4319 lines
168 KiB
C++
4319 lines
168 KiB
C++
/* Asynchronous replication implementation.
|
|
*
|
|
* Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
|
|
* Copyright (c) 2019 John Sully <john at eqalpha dot com>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* * Redistributions of source code must retain the above copyright notice,
|
|
* this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* * Neither the name of Redis nor the names of its contributors may be used
|
|
* to endorse or promote products derived from this software without
|
|
* specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
|
|
#include "server.h"
|
|
#include "cluster.h"
|
|
#include "bio.h"
|
|
#include "aelocker.h"
|
|
|
|
#include <sys/time.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/stat.h>
|
|
#include <mutex>
|
|
#include <algorithm>
|
|
#include <uuid/uuid.h>
|
|
#include <chrono>
|
|
#include <unordered_map>
|
|
#include <string>
|
|
|
|
void replicationDiscardCachedMaster(redisMaster *mi);
|
|
void replicationResurrectCachedMaster(redisMaster *mi, connection *conn);
|
|
void replicationSendAck(redisMaster *mi);
|
|
void putSlaveOnline(client *replica);
|
|
int cancelReplicationHandshake(redisMaster *mi);
|
|
static void propagateMasterStaleKeys();
|
|
|
|
/* We take a global flag to remember if this instance generated an RDB
|
|
* because of replication, so that we can remove the RDB file in case
|
|
* the instance is configured to have no persistence. */
|
|
int RDBGeneratedByReplication = 0;
|
|
|
|
/* --------------------------- Utility functions ---------------------------- */
|
|
|
|
/* Return the pointer to a string representing the replica ip:listening_port
|
|
* pair. Mostly useful for logging, since we want to log a replica using its
|
|
* IP address and its listening port which is more clear for the user, for
|
|
* example: "Closing connection with replica 10.1.2.3:6380". */
|
|
char *replicationGetSlaveName(client *c) {
|
|
static char buf[NET_PEER_ID_LEN];
|
|
char ip[NET_IP_STR_LEN];
|
|
|
|
ip[0] = '\0';
|
|
buf[0] = '\0';
|
|
if (c->slave_ip[0] != '\0' ||
|
|
connPeerToString(c->conn,ip,sizeof(ip),NULL) != -1)
|
|
{
|
|
/* Note that the 'ip' buffer is always larger than 'c->slave_ip' */
|
|
if (c->slave_ip[0] != '\0') memcpy(ip,c->slave_ip,sizeof(c->slave_ip));
|
|
|
|
if (c->slave_listening_port)
|
|
anetFormatAddr(buf,sizeof(buf),ip,c->slave_listening_port);
|
|
else
|
|
snprintf(buf,sizeof(buf),"%s:<unknown-replica-port>",ip);
|
|
} else {
|
|
snprintf(buf,sizeof(buf),"client id #%llu",
|
|
(unsigned long long) c->id);
|
|
}
|
|
return buf;
|
|
}
|
|
|
|
static bool FSameUuidNoNil(const unsigned char *a, const unsigned char *b)
|
|
{
|
|
unsigned char zeroCheck = 0;
|
|
for (int i = 0; i < UUID_BINARY_LEN; ++i)
|
|
{
|
|
if (a[i] != b[i])
|
|
return false;
|
|
zeroCheck |= a[i];
|
|
}
|
|
return (zeroCheck != 0); // if the UUID is nil then it is never equal
|
|
}
|
|
|
|
static bool FSameHost(client *clientA, client *clientB)
|
|
{
|
|
if (clientA == nullptr || clientB == nullptr)
|
|
return false;
|
|
|
|
const unsigned char *a = clientA->uuid;
|
|
const unsigned char *b = clientB->uuid;
|
|
|
|
return FSameUuidNoNil(a, b);
|
|
}
|
|
|
|
static bool FMasterHost(client *c)
|
|
{
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
if (FSameUuidNoNil(mi->master_uuid, c->uuid))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool FAnyDisconnectedMasters()
|
|
{
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
if (mi->repl_state != REPL_STATE_CONNECTED)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
client *replicaFromMaster(redisMaster *mi)
|
|
{
|
|
if (mi->master == nullptr)
|
|
return nullptr;
|
|
|
|
listIter liReplica;
|
|
listNode *lnReplica;
|
|
listRewind(g_pserver->slaves, &liReplica);
|
|
while ((lnReplica = listNext(&liReplica)) != nullptr)
|
|
{
|
|
client *replica = (client*)listNodeValue(lnReplica);
|
|
if (FSameHost(mi->master, replica))
|
|
return replica;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
/* Plain unlink() can block for quite some time in order to actually apply
|
|
* the file deletion to the filesystem. This call removes the file in a
|
|
* background thread instead. We actually just do close() in the thread,
|
|
* by using the fact that if there is another instance of the same file open,
|
|
* the foreground unlink() will not really do anything, and deleting the
|
|
* file will only happen once the last reference is lost. */
|
|
int bg_unlink(const char *filename) {
|
|
int fd = open(filename,O_RDONLY|O_NONBLOCK);
|
|
if (fd == -1) {
|
|
/* Can't open the file? Fall back to unlinking in the main thread. */
|
|
return unlink(filename);
|
|
} else {
|
|
/* The following unlink() will not do anything since file
|
|
* is still open. */
|
|
int retval = unlink(filename);
|
|
if (retval == -1) {
|
|
/* If we got an unlink error, we just return it, closing the
|
|
* new reference we have to the file. */
|
|
int old_errno = errno;
|
|
close(fd); /* This would overwrite our errno. So we saved it. */
|
|
errno = old_errno;
|
|
return -1;
|
|
}
|
|
bioCreateBackgroundJob(BIO_CLOSE_FILE,(void*)(long)fd,NULL,NULL);
|
|
return 0; /* Success. */
|
|
}
|
|
}
|
|
|
|
/* ---------------------------------- MASTER -------------------------------- */
|
|
|
|
void createReplicationBacklog(void) {
|
|
serverAssert(g_pserver->repl_backlog == NULL);
|
|
g_pserver->repl_backlog = (char*)zmalloc(g_pserver->repl_backlog_size, MALLOC_LOCAL);
|
|
g_pserver->repl_backlog_histlen = 0;
|
|
g_pserver->repl_backlog_idx = 0;
|
|
|
|
/* We don't have any data inside our buffer, but virtually the first
|
|
* byte we have is the next byte that will be generated for the
|
|
* replication stream. */
|
|
g_pserver->repl_backlog_off = g_pserver->master_repl_offset+1;
|
|
}
|
|
|
|
/* This function is called when the user modifies the replication backlog
|
|
* size at runtime. It is up to the function to both update the
|
|
* g_pserver->repl_backlog_size and to resize the buffer and setup it so that
|
|
* it contains the same data as the previous one (possibly less data, but
|
|
* the most recent bytes, or the same data and more free space in case the
|
|
* buffer is enlarged). */
|
|
void resizeReplicationBacklog(long long newsize) {
|
|
if (newsize < CONFIG_REPL_BACKLOG_MIN_SIZE)
|
|
newsize = CONFIG_REPL_BACKLOG_MIN_SIZE;
|
|
if (g_pserver->repl_backlog_size == newsize) return;
|
|
|
|
g_pserver->repl_backlog_size = newsize;
|
|
if (g_pserver->repl_backlog != NULL) {
|
|
/* What we actually do is to flush the old buffer and realloc a new
|
|
* empty one. It will refill with new data incrementally.
|
|
* The reason is that copying a few gigabytes adds latency and even
|
|
* worse often we need to alloc additional space before freeing the
|
|
* old buffer. */
|
|
zfree(g_pserver->repl_backlog);
|
|
g_pserver->repl_backlog = (char*)zmalloc(g_pserver->repl_backlog_size, MALLOC_LOCAL);
|
|
g_pserver->repl_backlog_histlen = 0;
|
|
g_pserver->repl_backlog_idx = 0;
|
|
/* Next byte we have is... the next since the buffer is empty. */
|
|
g_pserver->repl_backlog_off = g_pserver->master_repl_offset+1;
|
|
}
|
|
}
|
|
|
|
void freeReplicationBacklog(void) {
|
|
serverAssert(GlobalLocksAcquired());
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->slaves, &li);
|
|
while ((ln = listNext(&li))) {
|
|
// g_pserver->slaves should be empty, or filled with clients pending close
|
|
client *c = (client*)listNodeValue(ln);
|
|
serverAssert(c->flags & CLIENT_CLOSE_ASAP || FMasterHost(c));
|
|
}
|
|
zfree(g_pserver->repl_backlog);
|
|
g_pserver->repl_backlog = NULL;
|
|
}
|
|
|
|
/* Add data to the replication backlog.
|
|
* This function also increments the global replication offset stored at
|
|
* g_pserver->master_repl_offset, because there is no case where we want to feed
|
|
* the backlog without incrementing the offset. */
|
|
void feedReplicationBacklog(const void *ptr, size_t len) {
|
|
serverAssert(GlobalLocksAcquired());
|
|
const unsigned char *p = (const unsigned char*)ptr;
|
|
|
|
g_pserver->master_repl_offset += len;
|
|
|
|
/* This is a circular buffer, so write as much data we can at every
|
|
* iteration and rewind the "idx" index if we reach the limit. */
|
|
while(len) {
|
|
size_t thislen = g_pserver->repl_backlog_size - g_pserver->repl_backlog_idx;
|
|
if (thislen > len) thislen = len;
|
|
memcpy(g_pserver->repl_backlog+g_pserver->repl_backlog_idx,p,thislen);
|
|
g_pserver->repl_backlog_idx += thislen;
|
|
if (g_pserver->repl_backlog_idx == g_pserver->repl_backlog_size)
|
|
g_pserver->repl_backlog_idx = 0;
|
|
len -= thislen;
|
|
p += thislen;
|
|
g_pserver->repl_backlog_histlen += thislen;
|
|
}
|
|
if (g_pserver->repl_backlog_histlen > g_pserver->repl_backlog_size)
|
|
g_pserver->repl_backlog_histlen = g_pserver->repl_backlog_size;
|
|
/* Set the offset of the first byte we have in the backlog. */
|
|
g_pserver->repl_backlog_off = g_pserver->master_repl_offset -
|
|
g_pserver->repl_backlog_histlen + 1;
|
|
}
|
|
|
|
/* Wrapper for feedReplicationBacklog() that takes Redis string objects
|
|
* as input. */
|
|
void feedReplicationBacklogWithObject(robj *o) {
|
|
char llstr[LONG_STR_SIZE];
|
|
void *p;
|
|
size_t len;
|
|
|
|
if (o->encoding == OBJ_ENCODING_INT) {
|
|
len = ll2string(llstr,sizeof(llstr),(long)ptrFromObj(o));
|
|
p = llstr;
|
|
} else {
|
|
len = sdslen((sds)ptrFromObj(o));
|
|
p = ptrFromObj(o);
|
|
}
|
|
feedReplicationBacklog(p,len);
|
|
}
|
|
|
|
sds catCommandForAofAndActiveReplication(sds buf, struct redisCommand *cmd, robj **argv, int argc);
|
|
|
|
void replicationFeedSlave(client *replica, int dictid, robj **argv, int argc, bool fSendRaw)
|
|
{
|
|
char llstr[LONG_STR_SIZE];
|
|
std::unique_lock<decltype(replica->lock)> lock(replica->lock);
|
|
|
|
/* Send SELECT command to every replica if needed. */
|
|
if (g_pserver->replicaseldb != dictid) {
|
|
robj *selectcmd;
|
|
|
|
/* For a few DBs we have pre-computed SELECT command. */
|
|
if (dictid >= 0 && dictid < PROTO_SHARED_SELECT_CMDS) {
|
|
selectcmd = shared.select[dictid];
|
|
} else {
|
|
int dictid_len;
|
|
|
|
dictid_len = ll2string(llstr,sizeof(llstr),dictid);
|
|
selectcmd = createObject(OBJ_STRING,
|
|
sdscatprintf(sdsempty(),
|
|
"*2\r\n$6\r\nSELECT\r\n$%d\r\n%s\r\n",
|
|
dictid_len, llstr));
|
|
}
|
|
|
|
/* Add the SELECT command into the backlog. */
|
|
/* We don't do this for advanced replication because this will be done later when it adds the whole RREPLAY command */
|
|
if (g_pserver->repl_backlog && fSendRaw) feedReplicationBacklogWithObject(selectcmd);
|
|
|
|
/* Send it to slaves */
|
|
addReplyAsync(replica,selectcmd);
|
|
|
|
if (dictid < 0 || dictid >= PROTO_SHARED_SELECT_CMDS)
|
|
decrRefCount(selectcmd);
|
|
}
|
|
g_pserver->replicaseldb = dictid;
|
|
|
|
/* Feed slaves that are waiting for the initial SYNC (so these commands
|
|
* are queued in the output buffer until the initial SYNC completes),
|
|
* or are already in sync with the master. */
|
|
|
|
if (fSendRaw)
|
|
{
|
|
/* Add the multi bulk length. */
|
|
addReplyArrayLenAsync(replica,argc);
|
|
|
|
/* Finally any additional argument that was not stored inside the
|
|
* static buffer if any (from j to argc). */
|
|
for (int j = 0; j < argc; j++)
|
|
addReplyBulkAsync(replica,argv[j]);
|
|
}
|
|
else
|
|
{
|
|
struct redisCommand *cmd = lookupCommand(szFromObj(argv[0]));
|
|
sds buf = catCommandForAofAndActiveReplication(sdsempty(), cmd, argv, argc);
|
|
addReplyProtoAsync(replica, buf, sdslen(buf));
|
|
sdsfree(buf);
|
|
}
|
|
}
|
|
|
|
static int writeProtoNum(char *dst, const size_t cchdst, long long num)
|
|
{
|
|
if (cchdst < 1)
|
|
return 0;
|
|
dst[0] = '$';
|
|
int cch = 1;
|
|
cch += ll2string(dst + cch, cchdst - cch, digits10(num));
|
|
int chCpyT = std::min<int>(cchdst - cch, 2);
|
|
memcpy(dst + cch, "\r\n", chCpyT);
|
|
cch += chCpyT;
|
|
cch += ll2string(dst + cch, cchdst-cch, num);
|
|
chCpyT = std::min<int>(cchdst - cch, 3);
|
|
memcpy(dst + cch, "\r\n", chCpyT);
|
|
if (chCpyT == 3)
|
|
cch += 2;
|
|
else
|
|
cch += chCpyT;
|
|
return cch;
|
|
}
|
|
|
|
/* Propagate write commands to slaves, and populate the replication backlog
|
|
* as well. This function is used if the instance is a master: we use
|
|
* the commands received by our clients in order to create the replication
|
|
* stream. Instead if the instance is a replica and has sub-slaves attached,
|
|
* we use replicationFeedSlavesFromMaster() */
|
|
void replicationFeedSlaves(list *slaves, int dictid, robj **argv, int argc) {
|
|
listNode *ln, *lnReply;
|
|
listIter li, liReply;
|
|
int j, len;
|
|
serverAssert(GlobalLocksAcquired());
|
|
static client *fake = nullptr;
|
|
|
|
if (dictid < 0)
|
|
dictid = 0; // this can happen if we send a PING before any real operation
|
|
|
|
/* If the instance is not a top level master, return ASAP: we'll just proxy
|
|
* the stream of data we receive from our master instead, in order to
|
|
* propagate *identical* replication stream. In this way this replica can
|
|
* advertise the same replication ID as the master (since it shares the
|
|
* master replication history and has the same backlog and offsets). */
|
|
if (!g_pserver->fActiveReplica && listLength(g_pserver->masters)) return;
|
|
|
|
/* If there aren't slaves, and there is no backlog buffer to populate,
|
|
* we can return ASAP. */
|
|
if (g_pserver->repl_backlog == NULL && listLength(slaves) == 0) return;
|
|
|
|
/* We can't have slaves attached and no backlog. */
|
|
serverAssert(!(listLength(slaves) != 0 && g_pserver->repl_backlog == NULL));
|
|
|
|
if (fake == nullptr)
|
|
{
|
|
fake = createClient(nullptr, serverTL - g_pserver->rgthreadvar);
|
|
fake->flags |= CLIENT_FORCE_REPLY;
|
|
}
|
|
|
|
bool fSendRaw = !g_pserver->fActiveReplica;
|
|
replicationFeedSlave(fake, dictid, argv, argc, fSendRaw); // Note: updates the repl log, keep above the repl update code below
|
|
|
|
|
|
long long cchbuf = fake->bufpos;
|
|
listRewind(fake->reply, &liReply);
|
|
while ((lnReply = listNext(&liReply)))
|
|
{
|
|
clientReplyBlock* reply = (clientReplyBlock*)listNodeValue(lnReply);
|
|
cchbuf += reply->used;
|
|
}
|
|
|
|
serverAssert(argc > 0);
|
|
serverAssert(cchbuf > 0);
|
|
|
|
// The code below used to be: snprintf(proto, sizeof(proto), "*5\r\n$7\r\nRREPLAY\r\n$%d\r\n%s\r\n$%lld\r\n", (int)strlen(uuid), uuid, cchbuf);
|
|
// but that was much too slow
|
|
static const char *protoRREPLAY = "*5\r\n$7\r\nRREPLAY\r\n$36\r\n00000000-0000-0000-0000-000000000000\r\n$";
|
|
char proto[1024];
|
|
int cchProto = 0;
|
|
if (!fSendRaw)
|
|
{
|
|
char uuid[37];
|
|
uuid_unparse(cserver.uuid, uuid);
|
|
|
|
cchProto = strlen(protoRREPLAY);
|
|
memcpy(proto, protoRREPLAY, strlen(protoRREPLAY));
|
|
memcpy(proto + 22, uuid, 36); // Note UUID_STR_LEN includes the \0 trailing byte which we don't want
|
|
cchProto += ll2string(proto + cchProto, sizeof(proto)-cchProto, cchbuf);
|
|
memcpy(proto + cchProto, "\r\n", 3);
|
|
cchProto += 2;
|
|
}
|
|
|
|
long long master_repl_offset_start = g_pserver->master_repl_offset;
|
|
|
|
char szDbNum[128];
|
|
int cchDbNum = 0;
|
|
if (!fSendRaw)
|
|
cchDbNum = writeProtoNum(szDbNum, sizeof(szDbNum), dictid);
|
|
|
|
|
|
char szMvcc[128];
|
|
int cchMvcc = 0;
|
|
incrementMvccTstamp(); // Always increment MVCC tstamp so we're consistent with active and normal replication
|
|
if (!fSendRaw)
|
|
cchMvcc = writeProtoNum(szMvcc, sizeof(szMvcc), getMvccTstamp());
|
|
|
|
/* Write the command to the replication backlog if any. */
|
|
if (g_pserver->repl_backlog)
|
|
{
|
|
if (fSendRaw)
|
|
{
|
|
char aux[LONG_STR_SIZE+3];
|
|
|
|
/* Add the multi bulk reply length. */
|
|
aux[0] = '*';
|
|
len = ll2string(aux+1,sizeof(aux)-1,argc);
|
|
aux[len+1] = '\r';
|
|
aux[len+2] = '\n';
|
|
feedReplicationBacklog(aux,len+3);
|
|
|
|
for (j = 0; j < argc; j++) {
|
|
long objlen = stringObjectLen(argv[j]);
|
|
|
|
/* We need to feed the buffer with the object as a bulk reply
|
|
* not just as a plain string, so create the $..CRLF payload len
|
|
* and add the final CRLF */
|
|
aux[0] = '$';
|
|
len = ll2string(aux+1,sizeof(aux)-1,objlen);
|
|
aux[len+1] = '\r';
|
|
aux[len+2] = '\n';
|
|
feedReplicationBacklog(aux,len+3);
|
|
feedReplicationBacklogWithObject(argv[j]);
|
|
feedReplicationBacklog(aux+len+1,2);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
feedReplicationBacklog(proto, cchProto);
|
|
feedReplicationBacklog(fake->buf, fake->bufpos);
|
|
listRewind(fake->reply, &liReply);
|
|
while ((lnReply = listNext(&liReply)))
|
|
{
|
|
clientReplyBlock* reply = (clientReplyBlock*)listNodeValue(lnReply);
|
|
feedReplicationBacklog(reply->buf(), reply->used);
|
|
}
|
|
const char *crlf = "\r\n";
|
|
feedReplicationBacklog(crlf, 2);
|
|
feedReplicationBacklog(szDbNum, cchDbNum);
|
|
feedReplicationBacklog(szMvcc, cchMvcc);
|
|
}
|
|
}
|
|
|
|
/* Write the command to every replica. */
|
|
listRewind(slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
|
|
/* Don't feed slaves that are still waiting for BGSAVE to start */
|
|
if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_START) continue;
|
|
if (replica->flags & CLIENT_CLOSE_ASAP) continue;
|
|
std::unique_lock<decltype(replica->lock)> lock(replica->lock, std::defer_lock);
|
|
// When writing to clients on other threads the global lock is sufficient provided we only use AddReply*Async()
|
|
if (FCorrectThread(replica))
|
|
lock.lock();
|
|
if (serverTL->current_client && FSameHost(serverTL->current_client, replica))
|
|
{
|
|
replica->reploff_skipped += g_pserver->master_repl_offset - master_repl_offset_start;
|
|
continue;
|
|
}
|
|
|
|
/* Feed slaves that are waiting for the initial SYNC (so these commands
|
|
* are queued in the output buffer until the initial SYNC completes),
|
|
* or are already in sync with the master. */
|
|
|
|
if (!fSendRaw)
|
|
addReplyProtoAsync(replica, proto, cchProto);
|
|
|
|
addReplyProtoAsync(replica,fake->buf,fake->bufpos);
|
|
listRewind(fake->reply, &liReply);
|
|
while ((lnReply = listNext(&liReply)))
|
|
{
|
|
clientReplyBlock* reply = (clientReplyBlock*)listNodeValue(lnReply);
|
|
addReplyProtoAsync(replica, reply->buf(), reply->used);
|
|
}
|
|
|
|
if (!fSendRaw)
|
|
{
|
|
addReplyAsync(replica,shared.crlf);
|
|
addReplyProtoAsync(replica, szDbNum, cchDbNum);
|
|
addReplyProtoAsync(replica, szMvcc, cchMvcc);
|
|
}
|
|
}
|
|
|
|
// Cleanup cached fake client output buffers
|
|
fake->bufpos = 0;
|
|
fake->sentlen = 0;
|
|
fake->reply_bytes = 0;
|
|
listEmpty(fake->reply);
|
|
}
|
|
|
|
/* This is a debugging function that gets called when we detect something
|
|
* wrong with the replication protocol: the goal is to peek into the
|
|
* replication backlog and show a few final bytes to make simpler to
|
|
* guess what kind of bug it could be. */
|
|
void showLatestBacklog(void) {
|
|
if (g_pserver->repl_backlog == NULL) return;
|
|
|
|
long long dumplen = 256;
|
|
if (g_pserver->repl_backlog_histlen < dumplen)
|
|
dumplen = g_pserver->repl_backlog_histlen;
|
|
|
|
/* Identify the first byte to dump. */
|
|
long long idx =
|
|
(g_pserver->repl_backlog_idx + (g_pserver->repl_backlog_size - dumplen)) %
|
|
g_pserver->repl_backlog_size;
|
|
|
|
/* Scan the circular buffer to collect 'dumplen' bytes. */
|
|
sds dump = sdsempty();
|
|
while(dumplen) {
|
|
long long thislen =
|
|
((g_pserver->repl_backlog_size - idx) < dumplen) ?
|
|
(g_pserver->repl_backlog_size - idx) : dumplen;
|
|
|
|
dump = sdscatrepr(dump,g_pserver->repl_backlog+idx,thislen);
|
|
dumplen -= thislen;
|
|
idx = 0;
|
|
}
|
|
|
|
/* Finally log such bytes: this is vital debugging info to
|
|
* understand what happened. */
|
|
serverLog(LL_WARNING,"Latest backlog is: '%s'", dump);
|
|
sdsfree(dump);
|
|
}
|
|
|
|
/* This function is used in order to proxy what we receive from our master
|
|
* to our sub-slaves. */
|
|
#include <ctype.h>
|
|
void replicationFeedSlavesFromMasterStream(list *slaves, char *buf, size_t buflen) {
|
|
listNode *ln;
|
|
listIter li;
|
|
|
|
/* Debugging: this is handy to see the stream sent from master
|
|
* to slaves. Disabled with if(0). */
|
|
if (0) {
|
|
printf("%zu:",buflen);
|
|
for (size_t j = 0; j < buflen; j++) {
|
|
printf("%c", isprint(buf[j]) ? buf[j] : '.');
|
|
}
|
|
printf("\n");
|
|
}
|
|
|
|
if (g_pserver->repl_backlog) feedReplicationBacklog(buf,buflen);
|
|
listRewind(slaves,&li);
|
|
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
std::unique_lock<decltype(replica->lock)> ulock(replica->lock, std::defer_lock);
|
|
if (FCorrectThread(replica))
|
|
ulock.lock();
|
|
if (FMasterHost(replica))
|
|
continue; // Active Active case, don't feed back
|
|
|
|
/* Don't feed slaves that are still waiting for BGSAVE to start */
|
|
if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_START) continue;
|
|
addReplyProtoAsync(replica,buf,buflen);
|
|
}
|
|
|
|
if (listLength(slaves))
|
|
ProcessPendingAsyncWrites(); // flush them to their respective threads
|
|
}
|
|
|
|
void replicationFeedMonitors(client *c, list *monitors, int dictid, robj **argv, int argc) {
|
|
listNode *ln;
|
|
listIter li;
|
|
int j;
|
|
sds cmdrepr = sdsnew("+");
|
|
robj *cmdobj;
|
|
struct timeval tv;
|
|
serverAssert(GlobalLocksAcquired());
|
|
|
|
gettimeofday(&tv,NULL);
|
|
cmdrepr = sdscatprintf(cmdrepr,"%ld.%06ld ",(long)tv.tv_sec,(long)tv.tv_usec);
|
|
if (c->flags & CLIENT_LUA) {
|
|
cmdrepr = sdscatprintf(cmdrepr,"[%d lua] ",dictid);
|
|
} else if (c->flags & CLIENT_UNIX_SOCKET) {
|
|
cmdrepr = sdscatprintf(cmdrepr,"[%d unix:%s] ",dictid,g_pserver->unixsocket);
|
|
} else {
|
|
cmdrepr = sdscatprintf(cmdrepr,"[%d %s] ",dictid,getClientPeerId(c));
|
|
}
|
|
|
|
for (j = 0; j < argc; j++) {
|
|
if (argv[j]->encoding == OBJ_ENCODING_INT) {
|
|
cmdrepr = sdscatprintf(cmdrepr, "\"%ld\"", (long)ptrFromObj(argv[j]));
|
|
} else {
|
|
cmdrepr = sdscatrepr(cmdrepr,(char*)ptrFromObj(argv[j]),
|
|
sdslen((sds)ptrFromObj(argv[j])));
|
|
}
|
|
if (j != argc-1)
|
|
cmdrepr = sdscatlen(cmdrepr," ",1);
|
|
}
|
|
cmdrepr = sdscatlen(cmdrepr,"\r\n",2);
|
|
cmdobj = createObject(OBJ_STRING,cmdrepr);
|
|
|
|
listRewind(monitors,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *monitor = (client*)ln->value;
|
|
std::unique_lock<decltype(monitor->lock)> lock(monitor->lock, std::defer_lock);
|
|
// When writing to clients on other threads the global lock is sufficient provided we only use AddReply*Async()
|
|
if (FCorrectThread(c))
|
|
lock.lock();
|
|
addReplyAsync(monitor,cmdobj);
|
|
}
|
|
decrRefCount(cmdobj);
|
|
}
|
|
|
|
/* Feed the replica 'c' with the replication backlog starting from the
|
|
* specified 'offset' up to the end of the backlog. */
|
|
long long addReplyReplicationBacklog(client *c, long long offset) {
|
|
long long j, skip, len;
|
|
|
|
serverLog(LL_DEBUG, "[PSYNC] Replica request offset: %lld", offset);
|
|
|
|
if (g_pserver->repl_backlog_histlen == 0) {
|
|
serverLog(LL_DEBUG, "[PSYNC] Backlog history len is zero");
|
|
return 0;
|
|
}
|
|
|
|
serverLog(LL_DEBUG, "[PSYNC] Backlog size: %lld",
|
|
g_pserver->repl_backlog_size);
|
|
serverLog(LL_DEBUG, "[PSYNC] First byte: %lld",
|
|
g_pserver->repl_backlog_off);
|
|
serverLog(LL_DEBUG, "[PSYNC] History len: %lld",
|
|
g_pserver->repl_backlog_histlen);
|
|
serverLog(LL_DEBUG, "[PSYNC] Current index: %lld",
|
|
g_pserver->repl_backlog_idx);
|
|
|
|
/* Compute the amount of bytes we need to discard. */
|
|
skip = offset - g_pserver->repl_backlog_off;
|
|
serverLog(LL_DEBUG, "[PSYNC] Skipping: %lld", skip);
|
|
|
|
/* Point j to the oldest byte, that is actually our
|
|
* g_pserver->repl_backlog_off byte. */
|
|
j = (g_pserver->repl_backlog_idx +
|
|
(g_pserver->repl_backlog_size-g_pserver->repl_backlog_histlen)) %
|
|
g_pserver->repl_backlog_size;
|
|
serverLog(LL_DEBUG, "[PSYNC] Index of first byte: %lld", j);
|
|
|
|
/* Discard the amount of data to seek to the specified 'offset'. */
|
|
j = (j + skip) % g_pserver->repl_backlog_size;
|
|
|
|
/* Feed replica with data. Since it is a circular buffer we have to
|
|
* split the reply in two parts if we are cross-boundary. */
|
|
len = g_pserver->repl_backlog_histlen - skip;
|
|
serverLog(LL_DEBUG, "[PSYNC] Reply total length: %lld", len);
|
|
while(len) {
|
|
long long thislen =
|
|
((g_pserver->repl_backlog_size - j) < len) ?
|
|
(g_pserver->repl_backlog_size - j) : len;
|
|
|
|
serverLog(LL_DEBUG, "[PSYNC] addReply() length: %lld", thislen);
|
|
addReplySds(c,sdsnewlen(g_pserver->repl_backlog + j, thislen));
|
|
len -= thislen;
|
|
j = 0;
|
|
}
|
|
return g_pserver->repl_backlog_histlen - skip;
|
|
}
|
|
|
|
/* Return the offset to provide as reply to the PSYNC command received
|
|
* from the replica. The returned value is only valid immediately after
|
|
* the BGSAVE process started and before executing any other command
|
|
* from clients. */
|
|
long long getPsyncInitialOffset(void) {
|
|
return g_pserver->master_repl_offset;
|
|
}
|
|
|
|
/* Send a FULLRESYNC reply in the specific case of a full resynchronization,
|
|
* as a side effect setup the replica for a full sync in different ways:
|
|
*
|
|
* 1) Remember, into the replica client structure, the replication offset
|
|
* we sent here, so that if new slaves will later attach to the same
|
|
* background RDB saving process (by duplicating this client output
|
|
* buffer), we can get the right offset from this replica.
|
|
* 2) Set the replication state of the replica to WAIT_BGSAVE_END so that
|
|
* we start accumulating differences from this point.
|
|
* 3) Force the replication stream to re-emit a SELECT statement so
|
|
* the new replica incremental differences will start selecting the
|
|
* right database number.
|
|
*
|
|
* Normally this function should be called immediately after a successful
|
|
* BGSAVE for replication was started, or when there is one already in
|
|
* progress that we attached our replica to. */
|
|
int replicationSetupSlaveForFullResync(client *replica, long long offset) {
|
|
char buf[128];
|
|
int buflen;
|
|
|
|
replica->psync_initial_offset = offset;
|
|
replica->replstate = SLAVE_STATE_WAIT_BGSAVE_END;
|
|
/* We are going to accumulate the incremental changes for this
|
|
* replica as well. Set replicaseldb to -1 in order to force to re-emit
|
|
* a SELECT statement in the replication stream. */
|
|
g_pserver->replicaseldb = -1;
|
|
|
|
/* Don't send this reply to slaves that approached us with
|
|
* the old SYNC command. */
|
|
if (!(replica->flags & CLIENT_PRE_PSYNC)) {
|
|
buflen = snprintf(buf,sizeof(buf),"+FULLRESYNC %s %lld\r\n",
|
|
g_pserver->replid,offset);
|
|
if (connWrite(replica->conn,buf,buflen) != buflen) {
|
|
freeClientAsync(replica);
|
|
return C_ERR;
|
|
}
|
|
}
|
|
return C_OK;
|
|
}
|
|
|
|
/* This function handles the PSYNC command from the point of view of a
|
|
* master receiving a request for partial resynchronization.
|
|
*
|
|
* On success return C_OK, otherwise C_ERR is returned and we proceed
|
|
* with the usual full resync. */
|
|
int masterTryPartialResynchronization(client *c) {
|
|
serverAssert(GlobalLocksAcquired());
|
|
long long psync_offset, psync_len;
|
|
char *master_replid = (char*)ptrFromObj(c->argv[1]);
|
|
char buf[128];
|
|
int buflen;
|
|
|
|
/* Parse the replication offset asked by the replica. Go to full sync
|
|
* on parse error: this should never happen but we try to handle
|
|
* it in a robust way compared to aborting. */
|
|
if (getLongLongFromObjectOrReply(c,c->argv[2],&psync_offset,NULL) !=
|
|
C_OK) goto need_full_resync;
|
|
|
|
/* Is the replication ID of this master the same advertised by the wannabe
|
|
* replica via PSYNC? If the replication ID changed this master has a
|
|
* different replication history, and there is no way to continue.
|
|
*
|
|
* Note that there are two potentially valid replication IDs: the ID1
|
|
* and the ID2. The ID2 however is only valid up to a specific offset. */
|
|
if (strcasecmp(master_replid, g_pserver->replid) &&
|
|
(strcasecmp(master_replid, g_pserver->replid2) ||
|
|
psync_offset > g_pserver->second_replid_offset))
|
|
{
|
|
/* Run id "?" is used by slaves that want to force a full resync. */
|
|
if (master_replid[0] != '?') {
|
|
if (strcasecmp(master_replid, g_pserver->replid) &&
|
|
strcasecmp(master_replid, g_pserver->replid2))
|
|
{
|
|
serverLog(LL_NOTICE,"Partial resynchronization not accepted: "
|
|
"Replication ID mismatch (Replica asked for '%s', my "
|
|
"replication IDs are '%s' and '%s')",
|
|
master_replid, g_pserver->replid, g_pserver->replid2);
|
|
} else {
|
|
serverLog(LL_NOTICE,"Partial resynchronization not accepted: "
|
|
"Requested offset for second ID was %lld, but I can reply "
|
|
"up to %lld", psync_offset, g_pserver->second_replid_offset);
|
|
}
|
|
} else {
|
|
serverLog(LL_NOTICE,"Full resync requested by replica %s",
|
|
replicationGetSlaveName(c));
|
|
}
|
|
goto need_full_resync;
|
|
}
|
|
|
|
/* We still have the data our replica is asking for? */
|
|
if (!g_pserver->repl_backlog ||
|
|
psync_offset < g_pserver->repl_backlog_off ||
|
|
psync_offset > (g_pserver->repl_backlog_off + g_pserver->repl_backlog_histlen))
|
|
{
|
|
serverLog(LL_NOTICE,
|
|
"Unable to partial resync with replica %s for lack of backlog (Replica request was: %lld).", replicationGetSlaveName(c), psync_offset);
|
|
if (psync_offset > g_pserver->master_repl_offset) {
|
|
serverLog(LL_WARNING,
|
|
"Warning: replica %s tried to PSYNC with an offset that is greater than the master replication offset.", replicationGetSlaveName(c));
|
|
}
|
|
goto need_full_resync;
|
|
}
|
|
|
|
/* If we reached this point, we are able to perform a partial resync:
|
|
* 1) Set client state to make it a replica.
|
|
* 2) Inform the client we can continue with +CONTINUE
|
|
* 3) Send the backlog data (from the offset to the end) to the replica. */
|
|
c->flags |= CLIENT_SLAVE;
|
|
c->replstate = SLAVE_STATE_ONLINE;
|
|
c->repl_ack_time = g_pserver->unixtime;
|
|
c->repl_put_online_on_ack = 0;
|
|
listAddNodeTail(g_pserver->slaves,c);
|
|
|
|
/* We can't use the connection buffers since they are used to accumulate
|
|
* new commands at this stage. But we are sure the socket send buffer is
|
|
* empty so this write will never fail actually. */
|
|
if (c->slave_capa & SLAVE_CAPA_PSYNC2) {
|
|
buflen = snprintf(buf,sizeof(buf),"+CONTINUE %s\r\n", g_pserver->replid);
|
|
} else {
|
|
buflen = snprintf(buf,sizeof(buf),"+CONTINUE\r\n");
|
|
}
|
|
if (connWrite(c->conn,buf,buflen) != buflen) {
|
|
if (FCorrectThread(c))
|
|
freeClient(c);
|
|
else
|
|
freeClientAsync(c);
|
|
return C_OK;
|
|
}
|
|
psync_len = addReplyReplicationBacklog(c,psync_offset);
|
|
serverLog(LL_NOTICE,
|
|
"Partial resynchronization request from %s accepted. Sending %lld bytes of backlog starting from offset %lld.",
|
|
replicationGetSlaveName(c),
|
|
psync_len, psync_offset);
|
|
/* Note that we don't need to set the selected DB at g_pserver->replicaseldb
|
|
* to -1 to force the master to emit SELECT, since the replica already
|
|
* has this state from the previous connection with the master. */
|
|
|
|
refreshGoodSlavesCount();
|
|
|
|
/* Fire the replica change modules event. */
|
|
moduleFireServerEvent(REDISMODULE_EVENT_REPLICA_CHANGE,
|
|
REDISMODULE_SUBEVENT_REPLICA_CHANGE_ONLINE,
|
|
NULL);
|
|
|
|
return C_OK; /* The caller can return, no full resync needed. */
|
|
|
|
need_full_resync:
|
|
/* We need a full resync for some reason... Note that we can't
|
|
* reply to PSYNC right now if a full SYNC is needed. The reply
|
|
* must include the master offset at the time the RDB file we transfer
|
|
* is generated, so we need to delay the reply to that moment. */
|
|
return C_ERR;
|
|
}
|
|
|
|
/* Start a BGSAVE for replication goals, which is, selecting the disk or
|
|
* socket target depending on the configuration, and making sure that
|
|
* the script cache is flushed before to start.
|
|
*
|
|
* The mincapa argument is the bitwise AND among all the slaves capabilities
|
|
* of the slaves waiting for this BGSAVE, so represents the replica capabilities
|
|
* all the slaves support. Can be tested via SLAVE_CAPA_* macros.
|
|
*
|
|
* Side effects, other than starting a BGSAVE:
|
|
*
|
|
* 1) Handle the slaves in WAIT_START state, by preparing them for a full
|
|
* sync if the BGSAVE was successfully started, or sending them an error
|
|
* and dropping them from the list of slaves.
|
|
*
|
|
* 2) Flush the Lua scripting script cache if the BGSAVE was actually
|
|
* started.
|
|
*
|
|
* Returns C_OK on success or C_ERR otherwise. */
|
|
int startBgsaveForReplication(int mincapa) {
|
|
serverAssert(GlobalLocksAcquired());
|
|
int retval;
|
|
int socket_target = g_pserver->repl_diskless_sync && (mincapa & SLAVE_CAPA_EOF);
|
|
listIter li;
|
|
listNode *ln;
|
|
|
|
serverLog(LL_NOTICE,"Starting BGSAVE for SYNC with target: %s",
|
|
socket_target ? "replicas sockets" : "disk");
|
|
|
|
rdbSaveInfo rsi, *rsiptr;
|
|
rsiptr = rdbPopulateSaveInfo(&rsi);
|
|
/* Only do rdbSave* when rsiptr is not NULL,
|
|
* otherwise replica will miss repl-stream-db. */
|
|
if (rsiptr) {
|
|
if (socket_target)
|
|
retval = rdbSaveToSlavesSockets(rsiptr);
|
|
else
|
|
retval = rdbSaveBackground(rsiptr);
|
|
} else {
|
|
serverLog(LL_WARNING,"BGSAVE for replication: replication information not available, can't generate the RDB file right now. Try later.");
|
|
retval = C_ERR;
|
|
}
|
|
|
|
/* If we succeeded to start a BGSAVE with disk target, let's remember
|
|
* this fact, so that we can later delete the file if needed. Note
|
|
* that we don't set the flag to 1 if the feature is disabled, otherwise
|
|
* it would never be cleared: the file is not deleted. This way if
|
|
* the user enables it later with CONFIG SET, we are fine. */
|
|
if (retval == C_OK && !socket_target && g_pserver->rdb_del_sync_files)
|
|
RDBGeneratedByReplication = 1;
|
|
|
|
/* If we failed to BGSAVE, remove the slaves waiting for a full
|
|
* resynchronization from the list of slaves, inform them with
|
|
* an error about what happened, close the connection ASAP. */
|
|
if (retval == C_ERR) {
|
|
serverLog(LL_WARNING,"BGSAVE for replication failed");
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
std::unique_lock<decltype(replica->lock)> lock(replica->lock);
|
|
|
|
if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_START) {
|
|
replica->replstate = REPL_STATE_NONE;
|
|
replica->flags &= ~CLIENT_SLAVE;
|
|
listDelNode(g_pserver->slaves,ln);
|
|
addReplyError(replica,
|
|
"BGSAVE failed, replication can't continue");
|
|
replica->flags |= CLIENT_CLOSE_AFTER_REPLY;
|
|
}
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
/* If the target is socket, rdbSaveToSlavesSockets() already setup
|
|
* the slaves for a full resync. Otherwise for disk target do it now.*/
|
|
if (!socket_target) {
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
std::unique_lock<decltype(replica->lock)> lock(replica->lock);
|
|
|
|
if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_START) {
|
|
replicationSetupSlaveForFullResync(replica,
|
|
getPsyncInitialOffset());
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Flush the script cache, since we need that replica differences are
|
|
* accumulated without requiring slaves to match our cached scripts. */
|
|
if (retval == C_OK) replicationScriptCacheFlush();
|
|
return retval;
|
|
}
|
|
|
|
/* SYNC and PSYNC command implemenation. */
|
|
void syncCommand(client *c) {
|
|
/* ignore SYNC if already replica or in monitor mode */
|
|
if (c->flags & CLIENT_SLAVE) return;
|
|
|
|
/* Refuse SYNC requests if we are a replica but the link with our master
|
|
* is not ok... */
|
|
if (!g_pserver->fActiveReplica) {
|
|
if (FAnyDisconnectedMasters()) {
|
|
addReplySds(c,sdsnew("-NOMASTERLINK Can't SYNC while not connected with my master\r\n"));
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* SYNC can't be issued when the server has pending data to send to
|
|
* the client about already issued commands. We need a fresh reply
|
|
* buffer registering the differences between the BGSAVE and the current
|
|
* dataset, so that we can copy to other slaves if needed. */
|
|
if (clientHasPendingReplies(c)) {
|
|
addReplyError(c,"SYNC and PSYNC are invalid with pending output");
|
|
return;
|
|
}
|
|
|
|
serverLog(LL_NOTICE,"Replica %s asks for synchronization",
|
|
replicationGetSlaveName(c));
|
|
|
|
/* Try a partial resynchronization if this is a PSYNC command.
|
|
* If it fails, we continue with usual full resynchronization, however
|
|
* when this happens masterTryPartialResynchronization() already
|
|
* replied with:
|
|
*
|
|
* +FULLRESYNC <replid> <offset>
|
|
*
|
|
* So the replica knows the new replid and offset to try a PSYNC later
|
|
* if the connection with the master is lost. */
|
|
if (!strcasecmp((const char*)ptrFromObj(c->argv[0]),"psync")) {
|
|
if (masterTryPartialResynchronization(c) == C_OK) {
|
|
g_pserver->stat_sync_partial_ok++;
|
|
return; /* No full resync needed, return. */
|
|
} else {
|
|
char *master_replid = (char*)ptrFromObj(c->argv[1]);
|
|
|
|
/* Increment stats for failed PSYNCs, but only if the
|
|
* replid is not "?", as this is used by slaves to force a full
|
|
* resync on purpose when they are not albe to partially
|
|
* resync. */
|
|
if (master_replid[0] != '?') g_pserver->stat_sync_partial_err++;
|
|
}
|
|
} else {
|
|
/* If a replica uses SYNC, we are dealing with an old implementation
|
|
* of the replication protocol (like keydb-cli --replica). Flag the client
|
|
* so that we don't expect to receive REPLCONF ACK feedbacks. */
|
|
c->flags |= CLIENT_PRE_PSYNC;
|
|
}
|
|
|
|
/* Full resynchronization. */
|
|
g_pserver->stat_sync_full++;
|
|
|
|
/* Setup the replica as one waiting for BGSAVE to start. The following code
|
|
* paths will change the state if we handle the replica differently. */
|
|
c->replstate = SLAVE_STATE_WAIT_BGSAVE_START;
|
|
if (g_pserver->repl_disable_tcp_nodelay)
|
|
connDisableTcpNoDelay(c->conn); /* Non critical if it fails. */
|
|
c->repldbfd = -1;
|
|
c->flags |= CLIENT_SLAVE;
|
|
listAddNodeTail(g_pserver->slaves,c);
|
|
|
|
/* Create the replication backlog if needed. */
|
|
if (listLength(g_pserver->slaves) == 1 && g_pserver->repl_backlog == NULL) {
|
|
/* When we create the backlog from scratch, we always use a new
|
|
* replication ID and clear the ID2, since there is no valid
|
|
* past history. */
|
|
changeReplicationId();
|
|
clearReplicationId2();
|
|
createReplicationBacklog();
|
|
serverLog(LL_NOTICE,"Replication backlog created, my new "
|
|
"replication IDs are '%s' and '%s'",
|
|
g_pserver->replid, g_pserver->replid2);
|
|
}
|
|
|
|
/* CASE 1: BGSAVE is in progress, with disk target. */
|
|
if (g_pserver->rdb_child_pid != -1 &&
|
|
g_pserver->rdb_child_type == RDB_CHILD_TYPE_DISK)
|
|
{
|
|
/* Ok a background save is in progress. Let's check if it is a good
|
|
* one for replication, i.e. if there is another replica that is
|
|
* registering differences since the server forked to save. */
|
|
client *replica;
|
|
listNode *ln;
|
|
listIter li;
|
|
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
replica = (client*)ln->value;
|
|
if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_END) break;
|
|
}
|
|
|
|
/* To attach this replica, we check that it has at least all the
|
|
* capabilities of the replica that triggered the current BGSAVE. */
|
|
if (ln && ((c->slave_capa & replica->slave_capa) == replica->slave_capa)) {
|
|
/* Perfect, the server is already registering differences for
|
|
* another replica. Set the right state, and copy the buffer. */
|
|
copyClientOutputBuffer(c,replica);
|
|
replicationSetupSlaveForFullResync(c,replica->psync_initial_offset);
|
|
serverLog(LL_NOTICE,"Waiting for end of BGSAVE for SYNC");
|
|
} else {
|
|
/* No way, we need to wait for the next BGSAVE in order to
|
|
* register differences. */
|
|
serverLog(LL_NOTICE,"Can't attach the replica to the current BGSAVE. Waiting for next BGSAVE for SYNC");
|
|
}
|
|
|
|
/* CASE 2: BGSAVE is in progress, with socket target. */
|
|
} else if (g_pserver->rdb_child_pid != -1 &&
|
|
g_pserver->rdb_child_type == RDB_CHILD_TYPE_SOCKET)
|
|
{
|
|
/* There is an RDB child process but it is writing directly to
|
|
* children sockets. We need to wait for the next BGSAVE
|
|
* in order to synchronize. */
|
|
serverLog(LL_NOTICE,"Current BGSAVE has socket target. Waiting for next BGSAVE for SYNC");
|
|
|
|
/* CASE 3: There is no BGSAVE is progress. */
|
|
} else {
|
|
if (g_pserver->repl_diskless_sync && (c->slave_capa & SLAVE_CAPA_EOF)) {
|
|
/* Diskless replication RDB child is created inside
|
|
* replicationCron() since we want to delay its start a
|
|
* few seconds to wait for more slaves to arrive. */
|
|
if (g_pserver->repl_diskless_sync_delay)
|
|
serverLog(LL_NOTICE,"Delay next BGSAVE for diskless SYNC");
|
|
} else {
|
|
/* Target is disk (or the replica is not capable of supporting
|
|
* diskless replication) and we don't have a BGSAVE in progress,
|
|
* let's start one. */
|
|
if (!hasActiveChildProcess()) {
|
|
startBgsaveForReplication(c->slave_capa);
|
|
} else {
|
|
serverLog(LL_NOTICE,
|
|
"No BGSAVE in progress, but another BG operation is active. "
|
|
"BGSAVE for replication delayed");
|
|
}
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
void processReplconfUuid(client *c, robj *arg)
|
|
{
|
|
const char *remoteUUID = nullptr;
|
|
|
|
if (arg->type != OBJ_STRING)
|
|
goto LError;
|
|
|
|
remoteUUID = (const char*)ptrFromObj(arg);
|
|
if (strlen(remoteUUID) != 36)
|
|
goto LError;
|
|
|
|
if (uuid_parse(remoteUUID, c->uuid) != 0)
|
|
goto LError;
|
|
|
|
listIter liMi;
|
|
listNode *lnMi;
|
|
listRewind(g_pserver->masters, &liMi);
|
|
|
|
// Enforce a fair ordering for connection, if they attempt to connect before us close them out
|
|
// This must be consistent so that both make the same decision of who should proceed first
|
|
while ((lnMi = listNext(&liMi))) {
|
|
redisMaster *mi = (redisMaster*)listNodeValue(lnMi);
|
|
if (mi->repl_state == REPL_STATE_CONNECTED)
|
|
continue;
|
|
if (FSameUuidNoNil(mi->master_uuid, c->uuid)) {
|
|
// Decide based on UUID so both clients make the same decision of which host loses
|
|
// otherwise we may entere a loop where neither client can proceed
|
|
if (memcmp(mi->master_uuid, c->uuid, UUID_BINARY_LEN) < 0) {
|
|
freeClientAsync(c);
|
|
}
|
|
}
|
|
}
|
|
|
|
char szServerUUID[36 + 2]; // 1 for the '+', another for '\0'
|
|
szServerUUID[0] = '+';
|
|
uuid_unparse(cserver.uuid, szServerUUID+1);
|
|
addReplyProto(c, szServerUUID, 37);
|
|
addReplyProto(c, "\r\n", 2);
|
|
return;
|
|
|
|
LError:
|
|
addReplyError(c, "Invalid UUID");
|
|
return;
|
|
}
|
|
|
|
/* REPLCONF <option> <value> <option> <value> ...
|
|
* This command is used by a replica in order to configure the replication
|
|
* process before starting it with the SYNC command.
|
|
*
|
|
* Currently the only use of this command is to communicate to the master
|
|
* what is the listening port of the Slave redis instance, so that the
|
|
* master can accurately list slaves and their listening ports in
|
|
* the INFO output.
|
|
*
|
|
* In the future the same command can be used in order to configure
|
|
* the replication to initiate an incremental replication instead of a
|
|
* full resync. */
|
|
void replconfCommand(client *c) {
|
|
int j;
|
|
|
|
if ((c->argc % 2) == 0) {
|
|
/* Number of arguments must be odd to make sure that every
|
|
* option has a corresponding value. */
|
|
addReply(c,shared.syntaxerr);
|
|
return;
|
|
}
|
|
|
|
/* Process every option-value pair. */
|
|
for (j = 1; j < c->argc; j+=2) {
|
|
if (!strcasecmp((const char*)ptrFromObj(c->argv[j]),"listening-port")) {
|
|
long port;
|
|
|
|
if ((getLongFromObjectOrReply(c,c->argv[j+1],
|
|
&port,NULL) != C_OK))
|
|
return;
|
|
c->slave_listening_port = port;
|
|
} else if (!strcasecmp((const char*)ptrFromObj(c->argv[j]),"ip-address")) {
|
|
sds ip = (sds)ptrFromObj(c->argv[j+1]);
|
|
if (sdslen(ip) < sizeof(c->slave_ip)) {
|
|
memcpy(c->slave_ip,ip,sdslen(ip)+1);
|
|
} else {
|
|
addReplyErrorFormat(c,"REPLCONF ip-address provided by "
|
|
"replica instance is too long: %zd bytes", sdslen(ip));
|
|
return;
|
|
}
|
|
} else if (!strcasecmp((const char*)ptrFromObj(c->argv[j]),"capa")) {
|
|
/* Ignore capabilities not understood by this master. */
|
|
if (!strcasecmp((const char*)ptrFromObj(c->argv[j+1]),"eof"))
|
|
c->slave_capa |= SLAVE_CAPA_EOF;
|
|
else if (!strcasecmp((const char*)ptrFromObj(c->argv[j+1]),"psync2"))
|
|
c->slave_capa |= SLAVE_CAPA_PSYNC2;
|
|
else if (!strcasecmp((const char*)ptrFromObj(c->argv[j+1]), "activeExpire"))
|
|
c->slave_capa |= SLAVE_CAPA_ACTIVE_EXPIRE;
|
|
} else if (!strcasecmp((const char*)ptrFromObj(c->argv[j]),"ack")) {
|
|
/* REPLCONF ACK is used by replica to inform the master the amount
|
|
* of replication stream that it processed so far. It is an
|
|
* internal only command that normal clients should never use. */
|
|
long long offset;
|
|
|
|
if (!(c->flags & CLIENT_SLAVE)) return;
|
|
if ((getLongLongFromObject(c->argv[j+1], &offset) != C_OK))
|
|
return;
|
|
if (offset > c->repl_ack_off)
|
|
c->repl_ack_off = offset;
|
|
c->repl_ack_time = g_pserver->unixtime;
|
|
/* If this was a diskless replication, we need to really put
|
|
* the replica online when the first ACK is received (which
|
|
* confirms slave is online and ready to get more data). This
|
|
* allows for simpler and less CPU intensive EOF detection
|
|
* when streaming RDB files. */
|
|
if (c->repl_put_online_on_ack && c->replstate == SLAVE_STATE_ONLINE)
|
|
putSlaveOnline(c);
|
|
/* Note: this command does not reply anything! */
|
|
return;
|
|
} else if (!strcasecmp((const char*)ptrFromObj(c->argv[j]),"getack")) {
|
|
/* REPLCONF GETACK is used in order to request an ACK ASAP
|
|
* to the replica. */
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
replicationSendAck((redisMaster*)listNodeValue(ln));
|
|
}
|
|
return;
|
|
} else if (!strcasecmp((const char*)ptrFromObj(c->argv[j]),"uuid")) {
|
|
/* REPLCONF uuid is used to set and send the UUID of each host */
|
|
processReplconfUuid(c, c->argv[j+1]);
|
|
return; // the process function replies to the client for both error and success
|
|
} else {
|
|
addReplyErrorFormat(c,"Unrecognized REPLCONF option: %s",
|
|
(char*)ptrFromObj(c->argv[j]));
|
|
return;
|
|
}
|
|
}
|
|
addReply(c,shared.ok);
|
|
}
|
|
|
|
/* This function puts a replica in the online state, and should be called just
|
|
* after a replica received the RDB file for the initial synchronization, and
|
|
* we are finally ready to send the incremental stream of commands.
|
|
*
|
|
* It does a few things:
|
|
*
|
|
* 1) Put the slave in ONLINE state. Note that the function may also be called
|
|
* for a replicas that are already in ONLINE state, but having the flag
|
|
* repl_put_online_on_ack set to true: we still have to install the write
|
|
* handler in that case. This function will take care of that.
|
|
* 2) Make sure the writable event is re-installed, since calling the SYNC
|
|
* command disables it, so that we can accumulate output buffer without
|
|
* sending it to the replica.
|
|
* 3) Update the count of "good replicas". */
|
|
void putSlaveOnline(client *replica) {
|
|
replica->replstate = SLAVE_STATE_ONLINE;
|
|
replica->repl_put_online_on_ack = 0;
|
|
replica->repl_ack_time = g_pserver->unixtime; /* Prevent false timeout. */
|
|
if (connSetWriteHandler(replica->conn, sendReplyToClient, true) == C_ERR) {
|
|
serverLog(LL_WARNING,"Unable to register writable event for replica bulk transfer: %s", strerror(errno));
|
|
freeClient(replica);
|
|
return;
|
|
}
|
|
refreshGoodSlavesCount();
|
|
/* Fire the replica change modules event. */
|
|
moduleFireServerEvent(REDISMODULE_EVENT_REPLICA_CHANGE,
|
|
REDISMODULE_SUBEVENT_REPLICA_CHANGE_ONLINE,
|
|
NULL);
|
|
serverLog(LL_NOTICE,"Synchronization with replica %s succeeded",
|
|
replicationGetSlaveName(replica));
|
|
|
|
if (!(replica->slave_capa & SLAVE_CAPA_ACTIVE_EXPIRE) && g_pserver->fActiveReplica)
|
|
{
|
|
serverLog(LL_WARNING, "Warning: replica %s does not support active expiration. This client may not correctly process key expirations."
|
|
"\n\tThis is OK if you are in the process of an active upgrade.", replicationGetSlaveName(replica));
|
|
serverLog(LL_WARNING, "Connections between active replicas and traditional replicas is deprecated. This will be refused in future versions."
|
|
"\n\tPlease fix your replica topology");
|
|
}
|
|
}
|
|
|
|
/* We call this function periodically to remove an RDB file that was
|
|
* generated because of replication, in an instance that is otherwise
|
|
* without any persistence. We don't want instances without persistence
|
|
* to take RDB files around, this violates certain policies in certain
|
|
* environments. */
|
|
void removeRDBUsedToSyncReplicas(void) {
|
|
serverAssert(GlobalLocksAcquired());
|
|
|
|
/* If the feature is disabled, return ASAP but also clear the
|
|
* RDBGeneratedByReplication flag in case it was set. Otherwise if the
|
|
* feature was enabled, but gets disabled later with CONFIG SET, the
|
|
* flag may remain set to one: then next time the feature is re-enabled
|
|
* via CONFIG SET we have have it set even if no RDB was generated
|
|
* because of replication recently. */
|
|
if (!g_pserver->rdb_del_sync_files) {
|
|
RDBGeneratedByReplication = 0;
|
|
return;
|
|
}
|
|
|
|
if (allPersistenceDisabled() && RDBGeneratedByReplication) {
|
|
client *slave;
|
|
listNode *ln;
|
|
listIter li;
|
|
|
|
int delrdb = 1;
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
slave = (client*)ln->value;
|
|
if (slave->replstate == SLAVE_STATE_WAIT_BGSAVE_START ||
|
|
slave->replstate == SLAVE_STATE_WAIT_BGSAVE_END ||
|
|
slave->replstate == SLAVE_STATE_SEND_BULK)
|
|
{
|
|
delrdb = 0;
|
|
break; /* No need to check the other replicas. */
|
|
}
|
|
}
|
|
if (delrdb) {
|
|
struct stat sb;
|
|
if (lstat(g_pserver->rdb_filename,&sb) != -1) {
|
|
RDBGeneratedByReplication = 0;
|
|
serverLog(LL_NOTICE,
|
|
"Removing the RDB file used to feed replicas "
|
|
"in a persistence-less instance");
|
|
bg_unlink(g_pserver->rdb_filename);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
void sendBulkToSlave(connection *conn) {
|
|
client *replica = (client*)connGetPrivateData(conn);
|
|
serverAssert(FCorrectThread(replica));
|
|
ssize_t nwritten;
|
|
AeLocker aeLock;
|
|
std::unique_lock<fastlock> ul(replica->lock);
|
|
|
|
/* Before sending the RDB file, we send the preamble as configured by the
|
|
* replication process. Currently the preamble is just the bulk count of
|
|
* the file in the form "$<length>\r\n". */
|
|
if (replica->replpreamble) {
|
|
nwritten = connWrite(conn,replica->replpreamble,sdslen(replica->replpreamble));
|
|
if (nwritten == -1) {
|
|
serverLog(LL_VERBOSE,
|
|
"Write error sending RDB preamble to replica: %s",
|
|
connGetLastError(conn));
|
|
ul.unlock();
|
|
aeLock.arm(nullptr);
|
|
freeClient(replica);
|
|
return;
|
|
}
|
|
g_pserver->stat_net_output_bytes += nwritten;
|
|
sdsrange(replica->replpreamble,nwritten,-1);
|
|
if (sdslen(replica->replpreamble) == 0) {
|
|
sdsfree(replica->replpreamble);
|
|
replica->replpreamble = NULL;
|
|
/* fall through sending data. */
|
|
} else {
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* If the preamble was already transferred, send the RDB bulk data.
|
|
* try to use sendfile system call if supported, unless tls is enabled.
|
|
* fallback to normal read+write otherwise. */
|
|
nwritten = 0;
|
|
if (!nwritten) {
|
|
ssize_t buflen;
|
|
char buf[PROTO_IOBUF_LEN];
|
|
|
|
lseek(replica->repldbfd,replica->repldboff,SEEK_SET);
|
|
buflen = read(replica->repldbfd,buf,PROTO_IOBUF_LEN);
|
|
if (buflen <= 0) {
|
|
serverLog(LL_WARNING,"Read error sending DB to replica: %s",
|
|
(buflen == 0) ? "premature EOF" : strerror(errno));
|
|
ul.unlock();
|
|
aeLock.arm(nullptr);
|
|
freeClient(replica);
|
|
return;
|
|
}
|
|
if ((nwritten = connWrite(conn,buf,buflen)) == -1) {
|
|
if (connGetState(conn) != CONN_STATE_CONNECTED) {
|
|
serverLog(LL_WARNING,"Write error sending DB to replica: %s",
|
|
connGetLastError(conn));
|
|
ul.unlock();
|
|
aeLock.arm(nullptr);
|
|
freeClient(replica);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
|
|
replica->repldboff += nwritten;
|
|
g_pserver->stat_net_output_bytes += nwritten;
|
|
if (replica->repldboff == replica->repldbsize) {
|
|
close(replica->repldbfd);
|
|
replica->repldbfd = -1;
|
|
connSetWriteHandler(replica->conn,NULL);
|
|
putSlaveOnline(replica);
|
|
}
|
|
}
|
|
|
|
/* Remove one write handler from the list of connections waiting to be writable
|
|
* during rdb pipe transfer. */
|
|
void rdbPipeWriteHandlerConnRemoved(struct connection *conn) {
|
|
if (!connHasWriteHandler(conn))
|
|
return;
|
|
connSetWriteHandler(conn, NULL);
|
|
g_pserver->rdb_pipe_numconns_writing--;
|
|
/* if there are no more writes for now for this conn, or write error: */
|
|
if (g_pserver->rdb_pipe_numconns_writing == 0) {
|
|
aePostFunction(g_pserver->rgthreadvar[IDX_EVENT_LOOP_MAIN].el, []{
|
|
if (aeCreateFileEvent(serverTL->el, g_pserver->rdb_pipe_read, AE_READABLE, rdbPipeReadHandler,NULL) == AE_ERR) {
|
|
serverPanic("Unrecoverable error creating g_pserver->rdb_pipe_read file event.");
|
|
}
|
|
});
|
|
}
|
|
}
|
|
|
|
/* Called in diskless master during transfer of data from the rdb pipe, when
|
|
* the replica becomes writable again. */
|
|
void rdbPipeWriteHandler(struct connection *conn) {
|
|
serverAssert(g_pserver->rdb_pipe_bufflen>0);
|
|
client *slave = (client*)connGetPrivateData(conn);
|
|
AssertCorrectThread(slave);
|
|
int nwritten;
|
|
if ((nwritten = connWrite(conn, g_pserver->rdb_pipe_buff + slave->repldboff,
|
|
g_pserver->rdb_pipe_bufflen - slave->repldboff)) == -1)
|
|
{
|
|
if (connGetState(conn) == CONN_STATE_CONNECTED)
|
|
return; /* equivalent to EAGAIN */
|
|
serverLog(LL_WARNING,"Write error sending DB to replica: %s",
|
|
connGetLastError(conn));
|
|
freeClientAsync(slave);
|
|
return;
|
|
} else {
|
|
slave->repldboff += nwritten;
|
|
g_pserver->stat_net_output_bytes += nwritten;
|
|
if (slave->repldboff < g_pserver->rdb_pipe_bufflen)
|
|
return; /* more data to write.. */
|
|
}
|
|
rdbPipeWriteHandlerConnRemoved(conn);
|
|
}
|
|
|
|
/* When the the pipe serving diskless rdb transfer is drained (write end was
|
|
* closed), we can clean up all the temporary variables, and cleanup after the
|
|
* fork child. */
|
|
void RdbPipeCleanup() {
|
|
close(g_pserver->rdb_pipe_read);
|
|
zfree(g_pserver->rdb_pipe_conns);
|
|
g_pserver->rdb_pipe_conns = NULL;
|
|
g_pserver->rdb_pipe_numconns = 0;
|
|
g_pserver->rdb_pipe_numconns_writing = 0;
|
|
zfree(g_pserver->rdb_pipe_buff);
|
|
g_pserver->rdb_pipe_buff = NULL;
|
|
g_pserver->rdb_pipe_bufflen = 0;
|
|
|
|
/* Since we're avoiding to detect the child exited as long as the pipe is
|
|
* not drained, so now is the time to check. */
|
|
checkChildrenDone();
|
|
}
|
|
|
|
/* Called in diskless master, when there's data to read from the child's rdb pipe */
|
|
void rdbPipeReadHandler(struct aeEventLoop *eventLoop, int fd, void *clientData, int mask) {
|
|
UNUSED(mask);
|
|
UNUSED(clientData);
|
|
int i;
|
|
if (!g_pserver->rdb_pipe_buff)
|
|
g_pserver->rdb_pipe_buff = (char*)zmalloc(PROTO_IOBUF_LEN);
|
|
serverAssert(g_pserver->rdb_pipe_numconns_writing==0);
|
|
serverAssert(eventLoop == g_pserver->rgthreadvar[IDX_EVENT_LOOP_MAIN].el);
|
|
|
|
while (1) {
|
|
g_pserver->rdb_pipe_bufflen = read(fd, g_pserver->rdb_pipe_buff, PROTO_IOBUF_LEN);
|
|
if (g_pserver->rdb_pipe_bufflen < 0) {
|
|
if (errno == EAGAIN || errno == EWOULDBLOCK)
|
|
return;
|
|
serverLog(LL_WARNING,"Diskless rdb transfer, read error sending DB to replicas: %s", strerror(errno));
|
|
for (i=0; i < g_pserver->rdb_pipe_numconns; i++) {
|
|
connection *conn = g_pserver->rdb_pipe_conns[i];
|
|
if (!conn)
|
|
continue;
|
|
client *slave = (client*)connGetPrivateData(conn);
|
|
freeClient(slave);
|
|
g_pserver->rdb_pipe_conns[i] = NULL;
|
|
}
|
|
killRDBChild();
|
|
return;
|
|
}
|
|
|
|
if (g_pserver->rdb_pipe_bufflen == 0) {
|
|
/* EOF - write end was closed. */
|
|
int stillUp = 0;
|
|
aeDeleteFileEvent(eventLoop, g_pserver->rdb_pipe_read, AE_READABLE);
|
|
for (i=0; i < g_pserver->rdb_pipe_numconns; i++)
|
|
{
|
|
connection *conn = g_pserver->rdb_pipe_conns[i];
|
|
if (!conn)
|
|
continue;
|
|
stillUp++;
|
|
}
|
|
serverLog(LL_WARNING,"Diskless rdb transfer, done reading from pipe, %d replicas still up.", stillUp);
|
|
RdbPipeCleanup();
|
|
return;
|
|
}
|
|
|
|
int stillAlive = 0;
|
|
for (i=0; i < g_pserver->rdb_pipe_numconns; i++)
|
|
{
|
|
int nwritten;
|
|
connection *conn = g_pserver->rdb_pipe_conns[i];
|
|
if (!conn)
|
|
continue;
|
|
|
|
client *slave = (client*)connGetPrivateData(conn);
|
|
std::unique_lock<fastlock> ul(slave->lock);
|
|
if(slave->flags.load(std::memory_order_relaxed) & CLIENT_CLOSE_ASAP)
|
|
continue; // if we asked to free the client don't send any more data
|
|
|
|
// Normally it would be bug to talk a client conn from a different thread, but here we know nobody else will
|
|
// be sending anything while in this replication state so it is OK
|
|
if ((nwritten = connWrite(conn, g_pserver->rdb_pipe_buff, g_pserver->rdb_pipe_bufflen)) == -1) {
|
|
if (connGetState(conn) != CONN_STATE_CONNECTED) {
|
|
serverLog(LL_WARNING,"Diskless rdb transfer, write error sending DB to replica: %s",
|
|
connGetLastError(conn));
|
|
freeClientAsync(slave);
|
|
g_pserver->rdb_pipe_conns[i] = NULL;
|
|
continue;
|
|
}
|
|
/* An error and still in connected state, is equivalent to EAGAIN */
|
|
slave->repldboff = 0;
|
|
} else {
|
|
slave->repldboff = nwritten;
|
|
g_pserver->stat_net_output_bytes += nwritten;
|
|
}
|
|
/* If we were unable to write all the data to one of the replicas,
|
|
* setup write handler (and disable pipe read handler, below) */
|
|
if (nwritten != g_pserver->rdb_pipe_bufflen) {
|
|
g_pserver->rdb_pipe_numconns_writing++;
|
|
slave->postFunction([conn](client *) {
|
|
connSetWriteHandler(conn, rdbPipeWriteHandler);
|
|
});
|
|
}
|
|
stillAlive++;
|
|
}
|
|
|
|
if (stillAlive == 0) {
|
|
serverLog(LL_WARNING,"Diskless rdb transfer, last replica dropped, killing fork child.");
|
|
killRDBChild();
|
|
RdbPipeCleanup();
|
|
}
|
|
/* Remove the pipe read handler if at least one write handler was set. */
|
|
if (g_pserver->rdb_pipe_numconns_writing || stillAlive == 0) {
|
|
aeDeleteFileEvent(eventLoop, g_pserver->rdb_pipe_read, AE_READABLE);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* This function is called at the end of every background saving,
|
|
* or when the replication RDB transfer strategy is modified from
|
|
* disk to socket or the other way around.
|
|
*
|
|
* The goal of this function is to handle slaves waiting for a successful
|
|
* background saving in order to perform non-blocking synchronization, and
|
|
* to schedule a new BGSAVE if there are slaves that attached while a
|
|
* BGSAVE was in progress, but it was not a good one for replication (no
|
|
* other replica was accumulating differences).
|
|
*
|
|
* The argument bgsaveerr is C_OK if the background saving succeeded
|
|
* otherwise C_ERR is passed to the function.
|
|
* The 'type' argument is the type of the child that terminated
|
|
* (if it had a disk or socket target). */
|
|
void updateSlavesWaitingBgsave(int bgsaveerr, int type)
|
|
{
|
|
listNode *ln;
|
|
listIter li;
|
|
int startbgsave = 0;
|
|
int mincapa = -1;
|
|
serverAssert(GlobalLocksAcquired());
|
|
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
|
|
std::unique_lock<fastlock> ul(replica->lock);
|
|
|
|
if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_START) {
|
|
startbgsave = 1;
|
|
mincapa = (mincapa == -1) ? replica->slave_capa :
|
|
(mincapa & replica->slave_capa);
|
|
} else if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_END) {
|
|
struct redis_stat buf;
|
|
|
|
/* If this was an RDB on disk save, we have to prepare to send
|
|
* the RDB from disk to the replica socket. Otherwise if this was
|
|
* already an RDB -> Slaves socket transfer, used in the case of
|
|
* diskless replication, our work is trivial, we can just put
|
|
* the replica online. */
|
|
if (type == RDB_CHILD_TYPE_SOCKET) {
|
|
serverLog(LL_NOTICE,
|
|
"Streamed RDB transfer with replica %s succeeded (socket). Waiting for REPLCONF ACK from slave to enable streaming",
|
|
replicationGetSlaveName(replica));
|
|
/* Note: we wait for a REPLCONF ACK message from the replica in
|
|
* order to really put it online (install the write handler
|
|
* so that the accumulated data can be transferred). However
|
|
* we change the replication state ASAP, since our slave
|
|
* is technically online now.
|
|
*
|
|
* So things work like that:
|
|
*
|
|
* 1. We end trasnferring the RDB file via socket.
|
|
* 2. The replica is put ONLINE but the write handler
|
|
* is not installed.
|
|
* 3. The replica however goes really online, and pings us
|
|
* back via REPLCONF ACK commands.
|
|
* 4. Now we finally install the write handler, and send
|
|
* the buffers accumulated so far to the replica.
|
|
*
|
|
* But why we do that? Because the replica, when we stream
|
|
* the RDB directly via the socket, must detect the RDB
|
|
* EOF (end of file), that is a special random string at the
|
|
* end of the RDB (for streamed RDBs we don't know the length
|
|
* in advance). Detecting such final EOF string is much
|
|
* simpler and less CPU intensive if no more data is sent
|
|
* after such final EOF. So we don't want to glue the end of
|
|
* the RDB trasfer with the start of the other replication
|
|
* data. */
|
|
replica->replstate = SLAVE_STATE_ONLINE;
|
|
replica->repl_put_online_on_ack = 1;
|
|
replica->repl_ack_time = g_pserver->unixtime; /* Timeout otherwise. */
|
|
} else {
|
|
if (bgsaveerr != C_OK) {
|
|
ul.unlock();
|
|
if (FCorrectThread(replica))
|
|
freeClient(replica);
|
|
else
|
|
freeClientAsync(replica);
|
|
serverLog(LL_WARNING,"SYNC failed. BGSAVE child returned an error");
|
|
continue;
|
|
}
|
|
if ((replica->repldbfd = open(g_pserver->rdb_filename,O_RDONLY)) == -1 ||
|
|
redis_fstat(replica->repldbfd,&buf) == -1) {
|
|
ul.unlock();
|
|
if (FCorrectThread(replica))
|
|
freeClient(replica);
|
|
else
|
|
freeClientAsync(replica);
|
|
serverLog(LL_WARNING,"SYNC failed. Can't open/stat DB after BGSAVE: %s", strerror(errno));
|
|
continue;
|
|
}
|
|
replica->repldboff = 0;
|
|
replica->repldbsize = buf.st_size;
|
|
replica->replstate = SLAVE_STATE_SEND_BULK;
|
|
replica->replpreamble = sdscatprintf(sdsempty(),"$%lld\r\n",
|
|
(unsigned long long) replica->repldbsize);
|
|
|
|
if (FCorrectThread(replica))
|
|
{
|
|
connSetWriteHandler(replica->conn,NULL);
|
|
if (connSetWriteHandler(replica->conn,sendBulkToSlave) == C_ERR) {
|
|
ul.unlock();
|
|
freeClient(replica);
|
|
continue;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
replica->postFunction([](client *replica) {
|
|
connSetWriteHandler(replica->conn,NULL);
|
|
if (connSetWriteHandler(replica->conn,sendBulkToSlave) == C_ERR) {
|
|
freeClient(replica);
|
|
}
|
|
});
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (startbgsave)
|
|
startBgsaveForReplication(mincapa);
|
|
}
|
|
|
|
/* Change the current instance replication ID with a new, random one.
|
|
* This will prevent successful PSYNCs between this master and other
|
|
* slaves, so the command should be called when something happens that
|
|
* alters the current story of the dataset. */
|
|
void changeReplicationId(void) {
|
|
getRandomHexChars(g_pserver->replid,CONFIG_RUN_ID_SIZE);
|
|
g_pserver->replid[CONFIG_RUN_ID_SIZE] = '\0';
|
|
}
|
|
|
|
|
|
int hexchToInt(char ch)
|
|
{
|
|
if (ch >= '0' && ch <= '9')
|
|
return ch - '0';
|
|
if (ch >= 'a' && ch <= 'f')
|
|
return (ch - 'a') + 10;
|
|
return (ch - 'A') + 10;
|
|
}
|
|
void mergeReplicationId(const char *id)
|
|
{
|
|
for (int i = 0; i < CONFIG_RUN_ID_SIZE; ++i)
|
|
{
|
|
const char *charset = "0123456789abcdef";
|
|
g_pserver->replid[i] = charset[hexchToInt(g_pserver->replid[i]) ^ hexchToInt(id[i])];
|
|
}
|
|
}
|
|
|
|
/* Clear (invalidate) the secondary replication ID. This happens, for
|
|
* example, after a full resynchronization, when we start a new replication
|
|
* history. */
|
|
void clearReplicationId2(void) {
|
|
memset(g_pserver->replid2,'0',sizeof(g_pserver->replid));
|
|
g_pserver->replid2[CONFIG_RUN_ID_SIZE] = '\0';
|
|
g_pserver->second_replid_offset = -1;
|
|
}
|
|
|
|
/* Use the current replication ID / offset as secondary replication
|
|
* ID, and change the current one in order to start a new history.
|
|
* This should be used when an instance is switched from replica to master
|
|
* so that it can serve PSYNC requests performed using the master
|
|
* replication ID. */
|
|
void shiftReplicationId(void) {
|
|
memcpy(g_pserver->replid2,g_pserver->replid,sizeof(g_pserver->replid));
|
|
/* We set the second replid offset to the master offset + 1, since
|
|
* the replica will ask for the first byte it has not yet received, so
|
|
* we need to add one to the offset: for example if, as a replica, we are
|
|
* sure we have the same history as the master for 50 bytes, after we
|
|
* are turned into a master, we can accept a PSYNC request with offset
|
|
* 51, since the replica asking has the same history up to the 50th
|
|
* byte, and is asking for the new bytes starting at offset 51. */
|
|
g_pserver->second_replid_offset = g_pserver->master_repl_offset+1;
|
|
changeReplicationId();
|
|
serverLog(LL_WARNING,"Setting secondary replication ID to %s, valid up to offset: %lld. New replication ID is %s", g_pserver->replid2, g_pserver->second_replid_offset, g_pserver->replid);
|
|
}
|
|
|
|
/* ----------------------------------- SLAVE -------------------------------- */
|
|
|
|
/* Returns 1 if the given replication state is a handshake state,
|
|
* 0 otherwise. */
|
|
int slaveIsInHandshakeState(redisMaster *mi) {
|
|
return mi->repl_state >= REPL_STATE_RECEIVE_PONG &&
|
|
mi->repl_state <= REPL_STATE_RECEIVE_PSYNC;
|
|
}
|
|
|
|
/* Avoid the master to detect the replica is timing out while loading the
|
|
* RDB file in initial synchronization. We send a single newline character
|
|
* that is valid protocol but is guaranteed to either be sent entirely or
|
|
* not, since the byte is indivisible.
|
|
*
|
|
* The function is called in two contexts: while we flush the current
|
|
* data with emptyDb(), and while we load the new data received as an
|
|
* RDB file from the master. */
|
|
void replicationSendNewlineToMaster(redisMaster *mi) {
|
|
static time_t newline_sent;
|
|
if (time(NULL) != newline_sent) {
|
|
newline_sent = time(NULL);
|
|
/* Pinging back in this stage is best-effort. */
|
|
if (mi->repl_transfer_s) connWrite(mi->repl_transfer_s, "\n", 1);
|
|
}
|
|
}
|
|
|
|
/* Callback used by emptyDb() while flushing away old data to load
|
|
* the new dataset received by the master. */
|
|
void replicationEmptyDbCallback(void *privdata) {
|
|
UNUSED(privdata);
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
replicationSendNewlineToMaster((redisMaster*)listNodeValue(ln));
|
|
}
|
|
}
|
|
|
|
/* Once we have a link with the master and the synchroniziation was
|
|
* performed, this function materializes the master client we store
|
|
* at g_pserver->master, starting from the specified file descriptor. */
|
|
void replicationCreateMasterClient(redisMaster *mi, connection *conn, int dbid) {
|
|
serverAssert(mi->master == nullptr);
|
|
mi->master = createClient(conn, serverTL - g_pserver->rgthreadvar);
|
|
if (conn)
|
|
{
|
|
serverAssert(connGetPrivateData(mi->master->conn) == mi->master);
|
|
connSetReadHandler(mi->master->conn, readQueryFromClient, true);
|
|
}
|
|
mi->master->flags |= CLIENT_MASTER;
|
|
mi->master->authenticated = 1;
|
|
mi->master->reploff = mi->master_initial_offset;
|
|
mi->master->reploff_skipped = 0;
|
|
mi->master->read_reploff = mi->master->reploff;
|
|
mi->master->puser = NULL; /* This client can do everything. */
|
|
|
|
memcpy(mi->master->uuid, mi->master_uuid, UUID_BINARY_LEN);
|
|
memset(mi->master_uuid, 0, UUID_BINARY_LEN); // make sure people don't use this temp storage buffer
|
|
|
|
memcpy(mi->master->replid, mi->master_replid,
|
|
sizeof(mi->master_replid));
|
|
/* If master offset is set to -1, this master is old and is not
|
|
* PSYNC capable, so we flag it accordingly. */
|
|
if (mi->master->reploff == -1)
|
|
mi->master->flags |= CLIENT_PRE_PSYNC;
|
|
if (dbid != -1) selectDb(mi->master,dbid);
|
|
}
|
|
|
|
/* This function will try to re-enable the AOF file after the
|
|
* master-replica synchronization: if it fails after multiple attempts
|
|
* the replica cannot be considered reliable and exists with an
|
|
* error. */
|
|
void restartAOFAfterSYNC() {
|
|
unsigned int tries, max_tries = 10;
|
|
for (tries = 0; tries < max_tries; ++tries) {
|
|
if (startAppendOnly() == C_OK) break;
|
|
serverLog(LL_WARNING,
|
|
"Failed enabling the AOF after successful master synchronization! "
|
|
"Trying it again in one second.");
|
|
sleep(1);
|
|
}
|
|
if (tries == max_tries) {
|
|
serverLog(LL_WARNING,
|
|
"FATAL: this replica instance finished the synchronization with "
|
|
"its master, but the AOF can't be turned on. Exiting now.");
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
static int useDisklessLoad() {
|
|
/* compute boolean decision to use diskless load */
|
|
int enabled = g_pserver->repl_diskless_load == REPL_DISKLESS_LOAD_SWAPDB ||
|
|
(g_pserver->repl_diskless_load == REPL_DISKLESS_LOAD_WHEN_DB_EMPTY && dbTotalServerKeyCount()==0);
|
|
/* Check all modules handle read errors, otherwise it's not safe to use diskless load. */
|
|
if (enabled && !moduleAllDatatypesHandleErrors()) {
|
|
serverLog(LL_WARNING,
|
|
"Skipping diskless-load because there are modules that don't handle read errors.");
|
|
enabled = 0;
|
|
}
|
|
return enabled;
|
|
}
|
|
|
|
/* Helper function for readSyncBulkPayload() to make backups of the current
|
|
* DBs before socket-loading the new ones. The backups may be restored later
|
|
* or freed by disklessLoadRestoreBackups(). */
|
|
redisDb *disklessLoadMakeBackups(void) {
|
|
redisDb *backups = (redisDb*)zmalloc(sizeof(redisDb)*cserver.dbnum);
|
|
for (int i=0; i<cserver.dbnum; i++) {
|
|
backups[i] = g_pserver->db[i];
|
|
g_pserver->db[i].pdict = dictCreate(&dbDictType,NULL);
|
|
g_pserver->db[i].setexpire = new (MALLOC_LOCAL) expireset();
|
|
}
|
|
return backups;
|
|
}
|
|
|
|
/* Helper function for readSyncBulkPayload(): when replica-side diskless
|
|
* database loading is used, Redis makes a backup of the existing databases
|
|
* before loading the new ones from the socket.
|
|
*
|
|
* If the socket loading went wrong, we want to restore the old backups
|
|
* into the server databases. This function does just that in the case
|
|
* the 'restore' argument (the number of DBs to replace) is non-zero.
|
|
*
|
|
* When instead the loading succeeded we want just to free our old backups,
|
|
* in that case the funciton will do just that when 'restore' is 0. */
|
|
void disklessLoadRestoreBackups(redisDb *backup, int restore, int empty_db_flags)
|
|
{
|
|
if (restore) {
|
|
/* Restore. */
|
|
emptyDbGeneric(g_pserver->db,-1,empty_db_flags,replicationEmptyDbCallback);
|
|
for (int i=0; i<cserver.dbnum; i++) {
|
|
dictRelease(g_pserver->db[i].pdict);
|
|
delete g_pserver->db[i].setexpire;
|
|
g_pserver->db[i] = backup[i];
|
|
}
|
|
} else {
|
|
/* Delete (Pass EMPTYDB_BACKUP in order to avoid firing module events) . */
|
|
emptyDbGeneric(backup,-1,empty_db_flags|EMPTYDB_BACKUP,replicationEmptyDbCallback);
|
|
for (int i=0; i<cserver.dbnum; i++) {
|
|
dictRelease(backup[i].pdict);
|
|
delete backup[i].setexpire;
|
|
}
|
|
}
|
|
zfree(backup);
|
|
}
|
|
|
|
/* Asynchronously read the SYNC payload we receive from a master */
|
|
#define REPL_MAX_WRITTEN_BEFORE_FSYNC (1024*1024*8) /* 8 MB */
|
|
void readSyncBulkPayload(connection *conn) {
|
|
char buf[PROTO_IOBUF_LEN];
|
|
ssize_t nread, readlen, nwritten;
|
|
int use_diskless_load = useDisklessLoad();
|
|
redisDb *diskless_load_backup = NULL;
|
|
rdbSaveInfo rsi = RDB_SAVE_INFO_INIT;
|
|
int empty_db_flags = g_pserver->repl_slave_lazy_flush ? EMPTYDB_ASYNC :
|
|
EMPTYDB_NO_FLAGS;
|
|
off_t left;
|
|
// Should we update our database, or create from scratch?
|
|
int fUpdate = g_pserver->fActiveReplica || g_pserver->enable_multimaster;
|
|
redisMaster *mi = (redisMaster*)connGetPrivateData(conn);
|
|
|
|
serverAssert(GlobalLocksAcquired());
|
|
|
|
/* Static vars used to hold the EOF mark, and the last bytes received
|
|
* form the server: when they match, we reached the end of the transfer. */
|
|
static char eofmark[CONFIG_RUN_ID_SIZE];
|
|
static char lastbytes[CONFIG_RUN_ID_SIZE];
|
|
static int usemark = 0;
|
|
|
|
/* If repl_transfer_size == -1 we still have to read the bulk length
|
|
* from the master reply. */
|
|
if (mi->repl_transfer_size == -1) {
|
|
if (connSyncReadLine(conn,buf,1024,g_pserver->repl_syncio_timeout*1000) == -1) {
|
|
serverLog(LL_WARNING,
|
|
"I/O error reading bulk count from MASTER: %s",
|
|
strerror(errno));
|
|
goto error;
|
|
}
|
|
|
|
if (buf[0] == '-') {
|
|
serverLog(LL_WARNING,
|
|
"MASTER aborted replication with an error: %s",
|
|
buf+1);
|
|
goto error;
|
|
} else if (buf[0] == '\0') {
|
|
/* At this stage just a newline works as a PING in order to take
|
|
* the connection live. So we refresh our last interaction
|
|
* timestamp. */
|
|
mi->repl_transfer_lastio = g_pserver->unixtime;
|
|
return;
|
|
} else if (buf[0] != '$') {
|
|
serverLog(LL_WARNING,"Bad protocol from MASTER, the first byte is not '$' (we received '%s'), are you sure the host and port are right?", buf);
|
|
goto error;
|
|
}
|
|
|
|
/* There are two possible forms for the bulk payload. One is the
|
|
* usual $<count> bulk format. The other is used for diskless transfers
|
|
* when the master does not know beforehand the size of the file to
|
|
* transfer. In the latter case, the following format is used:
|
|
*
|
|
* $EOF:<40 bytes delimiter>
|
|
*
|
|
* At the end of the file the announced delimiter is transmitted. The
|
|
* delimiter is long and random enough that the probability of a
|
|
* collision with the actual file content can be ignored. */
|
|
if (strncmp(buf+1,"EOF:",4) == 0 && strlen(buf+5) >= CONFIG_RUN_ID_SIZE) {
|
|
usemark = 1;
|
|
memcpy(eofmark,buf+5,CONFIG_RUN_ID_SIZE);
|
|
memset(lastbytes,0,CONFIG_RUN_ID_SIZE);
|
|
/* Set any repl_transfer_size to avoid entering this code path
|
|
* at the next call. */
|
|
mi->repl_transfer_size = 0;
|
|
serverLog(LL_NOTICE,
|
|
"MASTER <-> REPLICA sync: receiving streamed RDB from master with EOF %s",
|
|
use_diskless_load? "to parser":"to disk");
|
|
} else {
|
|
usemark = 0;
|
|
mi->repl_transfer_size = strtol(buf+1,NULL,10);
|
|
serverLog(LL_NOTICE,
|
|
"MASTER <-> REPLICA sync: receiving %lld bytes from master %s",
|
|
(long long) mi->repl_transfer_size,
|
|
use_diskless_load? "to parser":"to disk");
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (!use_diskless_load) {
|
|
/* Read the data from the socket, store it to a file and search
|
|
* for the EOF. */
|
|
if (usemark) {
|
|
readlen = sizeof(buf);
|
|
} else {
|
|
left = mi->repl_transfer_size - mi->repl_transfer_read;
|
|
readlen = (left < (signed)sizeof(buf)) ? left : (signed)sizeof(buf);
|
|
}
|
|
|
|
nread = connRead(conn,buf,readlen);
|
|
if (nread <= 0) {
|
|
if (connGetState(conn) == CONN_STATE_CONNECTED) {
|
|
/* equivalent to EAGAIN */
|
|
return;
|
|
}
|
|
serverLog(LL_WARNING,"I/O error trying to sync with MASTER: %s",
|
|
(nread == -1) ? strerror(errno) : "connection lost");
|
|
cancelReplicationHandshake(mi);
|
|
return;
|
|
}
|
|
g_pserver->stat_net_input_bytes += nread;
|
|
|
|
/* When a mark is used, we want to detect EOF asap in order to avoid
|
|
* writing the EOF mark into the file... */
|
|
int eof_reached = 0;
|
|
|
|
if (usemark) {
|
|
/* Update the last bytes array, and check if it matches our
|
|
* delimiter. */
|
|
if (nread >= CONFIG_RUN_ID_SIZE) {
|
|
memcpy(lastbytes,buf+nread-CONFIG_RUN_ID_SIZE,
|
|
CONFIG_RUN_ID_SIZE);
|
|
} else {
|
|
int rem = CONFIG_RUN_ID_SIZE-nread;
|
|
memmove(lastbytes,lastbytes+nread,rem);
|
|
memcpy(lastbytes+rem,buf,nread);
|
|
}
|
|
if (memcmp(lastbytes,eofmark,CONFIG_RUN_ID_SIZE) == 0)
|
|
eof_reached = 1;
|
|
}
|
|
|
|
/* Update the last I/O time for the replication transfer (used in
|
|
* order to detect timeouts during replication), and write what we
|
|
* got from the socket to the dump file on disk. */
|
|
mi->repl_transfer_lastio = g_pserver->unixtime;
|
|
if ((nwritten = write(mi->repl_transfer_fd,buf,nread)) != nread) {
|
|
serverLog(LL_WARNING,
|
|
"Write error or short write writing to the DB dump file "
|
|
"needed for MASTER <-> REPLICA synchronization: %s",
|
|
(nwritten == -1) ? strerror(errno) : "short write");
|
|
goto error;
|
|
}
|
|
mi->repl_transfer_read += nread;
|
|
|
|
/* Delete the last 40 bytes from the file if we reached EOF. */
|
|
if (usemark && eof_reached) {
|
|
if (ftruncate(mi->repl_transfer_fd,
|
|
mi->repl_transfer_read - CONFIG_RUN_ID_SIZE) == -1)
|
|
{
|
|
serverLog(LL_WARNING,
|
|
"Error truncating the RDB file received from the master "
|
|
"for SYNC: %s", strerror(errno));
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
/* Sync data on disk from time to time, otherwise at the end of the
|
|
* transfer we may suffer a big delay as the memory buffers are copied
|
|
* into the actual disk. */
|
|
if (mi->repl_transfer_read >=
|
|
mi->repl_transfer_last_fsync_off + REPL_MAX_WRITTEN_BEFORE_FSYNC)
|
|
{
|
|
off_t sync_size = mi->repl_transfer_read -
|
|
mi->repl_transfer_last_fsync_off;
|
|
rdb_fsync_range(mi->repl_transfer_fd,
|
|
mi->repl_transfer_last_fsync_off, sync_size);
|
|
mi->repl_transfer_last_fsync_off += sync_size;
|
|
}
|
|
|
|
/* Check if the transfer is now complete */
|
|
if (!usemark) {
|
|
if (mi->repl_transfer_read == mi->repl_transfer_size)
|
|
eof_reached = 1;
|
|
}
|
|
|
|
/* If the transfer is yet not complete, we need to read more, so
|
|
* return ASAP and wait for the handler to be called again. */
|
|
if (!eof_reached) return;
|
|
}
|
|
|
|
/* We reach this point in one of the following cases:
|
|
*
|
|
* 1. The replica is using diskless replication, that is, it reads data
|
|
* directly from the socket to the Redis memory, without using
|
|
* a temporary RDB file on disk. In that case we just block and
|
|
* read everything from the socket.
|
|
*
|
|
* 2. Or when we are done reading from the socket to the RDB file, in
|
|
* such case we want just to read the RDB file in memory. */
|
|
|
|
/* We need to stop any AOF rewriting child before flusing and parsing
|
|
* the RDB, otherwise we'll create a copy-on-write disaster. */
|
|
if (g_pserver->aof_state != AOF_OFF) stopAppendOnly();
|
|
|
|
/* When diskless RDB loading is used by replicas, it may be configured
|
|
* in order to save the current DB instead of throwing it away,
|
|
* so that we can restore it in case of failed transfer. */
|
|
if (use_diskless_load &&
|
|
g_pserver->repl_diskless_load == REPL_DISKLESS_LOAD_SWAPDB)
|
|
{
|
|
/* Create a backup of server.db[] and initialize to empty
|
|
* dictionaries */
|
|
diskless_load_backup = disklessLoadMakeBackups();
|
|
}
|
|
/* We call to emptyDb even in case of REPL_DISKLESS_LOAD_SWAPDB
|
|
* (Where disklessLoadMakeBackups left server.db empty) because we
|
|
* want to execute all the auxiliary logic of emptyDb (Namely,
|
|
* fire module events) */
|
|
if (!fUpdate) {
|
|
serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Flushing old data");
|
|
emptyDb(-1,empty_db_flags,replicationEmptyDbCallback);
|
|
}
|
|
|
|
/* Before loading the DB into memory we need to delete the readable
|
|
* handler, otherwise it will get called recursively since
|
|
* rdbLoad() will call the event loop to process events from time to
|
|
* time for non blocking loading. */
|
|
connSetReadHandler(conn, NULL);
|
|
serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Loading DB in memory");
|
|
|
|
if (use_diskless_load) {
|
|
rio rdb;
|
|
rioInitWithConn(&rdb,conn,mi->repl_transfer_size);
|
|
|
|
/* Put the socket in blocking mode to simplify RDB transfer.
|
|
* We'll restore it when the RDB is received. */
|
|
connBlock(conn);
|
|
connRecvTimeout(conn, g_pserver->repl_timeout*1000);
|
|
startLoading(mi->repl_transfer_size, RDBFLAGS_REPLICATION);
|
|
|
|
if (rdbLoadRio(&rdb,RDBFLAGS_REPLICATION,&rsi) != C_OK) {
|
|
/* RDB loading failed. */
|
|
stopLoading(0);
|
|
serverLog(LL_WARNING,
|
|
"Failed trying to load the MASTER synchronization DB "
|
|
"from socket");
|
|
cancelReplicationHandshake(mi);
|
|
rioFreeConn(&rdb, NULL);
|
|
if (g_pserver->repl_diskless_load == REPL_DISKLESS_LOAD_SWAPDB) {
|
|
/* Restore the backed up databases. */
|
|
disklessLoadRestoreBackups(diskless_load_backup,1,
|
|
empty_db_flags);
|
|
} else {
|
|
/* Remove the half-loaded data in case we started with
|
|
* an empty replica. */
|
|
emptyDb(-1,empty_db_flags,replicationEmptyDbCallback);
|
|
}
|
|
|
|
/* Note that there's no point in restarting the AOF on SYNC
|
|
* failure, it'll be restarted when sync succeeds or the replica
|
|
* gets promoted. */
|
|
return;
|
|
}
|
|
stopLoading(1);
|
|
|
|
/* RDB loading succeeded if we reach this point. */
|
|
if (g_pserver->repl_diskless_load == REPL_DISKLESS_LOAD_SWAPDB) {
|
|
/* Delete the backup databases we created before starting to load
|
|
* the new RDB. Now the RDB was loaded with success so the old
|
|
* data is useless. */
|
|
disklessLoadRestoreBackups(diskless_load_backup,0,empty_db_flags);
|
|
}
|
|
|
|
/* Verify the end mark is correct. */
|
|
if (usemark) {
|
|
if (!rioRead(&rdb,buf,CONFIG_RUN_ID_SIZE) ||
|
|
memcmp(buf,eofmark,CONFIG_RUN_ID_SIZE) != 0)
|
|
{
|
|
serverLog(LL_WARNING,"Replication stream EOF marker is broken");
|
|
cancelReplicationHandshake(mi);
|
|
rioFreeConn(&rdb, NULL);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* Cleanup and restore the socket to the original state to continue
|
|
* with the normal replication. */
|
|
rioFreeConn(&rdb, NULL);
|
|
connNonBlock(conn);
|
|
connRecvTimeout(conn,0);
|
|
} else {
|
|
/* Ensure background save doesn't overwrite synced data */
|
|
if (g_pserver->rdb_child_pid != -1) {
|
|
serverLog(LL_NOTICE,
|
|
"Replica is about to load the RDB file received from the "
|
|
"master, but there is a pending RDB child running. "
|
|
"Killing process %ld and removing its temp file to avoid "
|
|
"any race",
|
|
(long) g_pserver->rdb_child_pid);
|
|
killRDBChild();
|
|
}
|
|
|
|
const char *rdb_filename = mi->repl_transfer_tmpfile;
|
|
|
|
/* Rename rdb like renaming rewrite aof asynchronously. */
|
|
if (!fUpdate) {
|
|
int old_rdb_fd = open(g_pserver->rdb_filename,O_RDONLY|O_NONBLOCK);
|
|
if (rename(mi->repl_transfer_tmpfile,g_pserver->rdb_filename) == -1) {
|
|
serverLog(LL_WARNING,
|
|
"Failed trying to rename the temp DB into %s in "
|
|
"MASTER <-> REPLICA synchronization: %s",
|
|
g_pserver->rdb_filename, strerror(errno));
|
|
cancelReplicationHandshake(mi);
|
|
if (old_rdb_fd != -1) close(old_rdb_fd);
|
|
return;
|
|
}
|
|
rdb_filename = g_pserver->rdb_filename;
|
|
|
|
/* Close old rdb asynchronously. */
|
|
if (old_rdb_fd != -1) bioCreateBackgroundJob(BIO_CLOSE_FILE,(void*)(long)old_rdb_fd,NULL,NULL);
|
|
}
|
|
|
|
if (g_pserver->fActiveReplica)
|
|
{
|
|
rsi.mvccMinThreshold = mi->mvccLastSync;
|
|
if (mi->staleKeyMap != nullptr)
|
|
mi->staleKeyMap->clear();
|
|
else
|
|
mi->staleKeyMap = new (MALLOC_LOCAL) std::map<int, std::vector<robj_sharedptr>>();
|
|
rsi.mi = mi;
|
|
}
|
|
if (rdbLoadFile(rdb_filename,&rsi,RDBFLAGS_REPLICATION) != C_OK) {
|
|
serverLog(LL_WARNING,
|
|
"Failed trying to load the MASTER synchronization "
|
|
"DB from disk");
|
|
cancelReplicationHandshake(mi);
|
|
if (g_pserver->rdb_del_sync_files && allPersistenceDisabled()) {
|
|
serverLog(LL_NOTICE,"Removing the RDB file obtained from "
|
|
"the master. This replica has persistence "
|
|
"disabled");
|
|
bg_unlink(g_pserver->rdb_filename);
|
|
}
|
|
/* Note that there's no point in restarting the AOF on sync failure,
|
|
it'll be restarted when sync succeeds or replica promoted. */
|
|
return;
|
|
}
|
|
|
|
/* Cleanup. */
|
|
if (g_pserver->rdb_del_sync_files && allPersistenceDisabled()) {
|
|
serverLog(LL_NOTICE,"Removing the RDB file obtained from "
|
|
"the master. This replica has persistence "
|
|
"disabled");
|
|
bg_unlink(g_pserver->rdb_filename);
|
|
}
|
|
if (fUpdate)
|
|
unlink(mi->repl_transfer_tmpfile);
|
|
zfree(mi->repl_transfer_tmpfile);
|
|
close(mi->repl_transfer_fd);
|
|
mi->repl_transfer_fd = -1;
|
|
mi->repl_transfer_tmpfile = NULL;
|
|
}
|
|
|
|
/* Final setup of the connected slave <- master link */
|
|
replicationCreateMasterClient(mi,mi->repl_transfer_s,rsi.repl_stream_db);
|
|
mi->repl_transfer_s = nullptr;
|
|
mi->repl_state = REPL_STATE_CONNECTED;
|
|
mi->repl_down_since = 0;
|
|
|
|
/* Fire the master link modules event. */
|
|
moduleFireServerEvent(REDISMODULE_EVENT_MASTER_LINK_CHANGE,
|
|
REDISMODULE_SUBEVENT_MASTER_LINK_UP,
|
|
NULL);
|
|
|
|
/* After a full resynchroniziation we use the replication ID and
|
|
* offset of the master. The secondary ID / offset are cleared since
|
|
* we are starting a new history. */
|
|
if (fUpdate)
|
|
{
|
|
mergeReplicationId(mi->master->replid);
|
|
}
|
|
else
|
|
{
|
|
/* After a full resynchroniziation we use the replication ID and
|
|
* offset of the master. The secondary ID / offset are cleared since
|
|
* we are starting a new history. */
|
|
memcpy(g_pserver->replid,mi->master->replid,sizeof(g_pserver->replid));
|
|
g_pserver->master_repl_offset = mi->master->reploff;
|
|
}
|
|
clearReplicationId2();
|
|
|
|
/* Let's create the replication backlog if needed. Slaves need to
|
|
* accumulate the backlog regardless of the fact they have sub-slaves
|
|
* or not, in order to behave correctly if they are promoted to
|
|
* masters after a failover. */
|
|
if (g_pserver->repl_backlog == NULL) createReplicationBacklog();
|
|
serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Finished with success");
|
|
|
|
if (cserver.supervised_mode == SUPERVISED_SYSTEMD) {
|
|
redisCommunicateSystemd("STATUS=MASTER <-> REPLICA sync: Finished with success. Ready to accept connections.\n");
|
|
redisCommunicateSystemd("READY=1\n");
|
|
}
|
|
|
|
/* Restart the AOF subsystem now that we finished the sync. This
|
|
* will trigger an AOF rewrite, and when done will start appending
|
|
* to the new file. */
|
|
if (g_pserver->aof_enabled) restartAOFAfterSYNC();
|
|
return;
|
|
|
|
error:
|
|
cancelReplicationHandshake(mi);
|
|
return;
|
|
}
|
|
|
|
/* Send a synchronous command to the master. Used to send AUTH and
|
|
* REPLCONF commands before starting the replication with SYNC.
|
|
*
|
|
* The command returns an sds string representing the result of the
|
|
* operation. On error the first byte is a "-".
|
|
*/
|
|
#define SYNC_CMD_READ (1<<0)
|
|
#define SYNC_CMD_WRITE (1<<1)
|
|
#define SYNC_CMD_FULL (SYNC_CMD_READ|SYNC_CMD_WRITE)
|
|
char *sendSynchronousCommand(redisMaster *mi, int flags, connection *conn, ...)
|
|
{
|
|
/* Create the command to send to the master, we use redis binary
|
|
* protocol to make sure correct arguments are sent. This function
|
|
* is not safe for all binary data. */
|
|
if (flags & SYNC_CMD_WRITE) {
|
|
char *arg;
|
|
va_list ap;
|
|
sds cmd = sdsempty();
|
|
sds cmdargs = sdsempty();
|
|
size_t argslen = 0;
|
|
va_start(ap,conn);
|
|
|
|
while(1) {
|
|
arg = va_arg(ap, char*);
|
|
if (arg == NULL) break;
|
|
|
|
cmdargs = sdscatprintf(cmdargs,"$%zu\r\n%s\r\n",strlen(arg),arg);
|
|
argslen++;
|
|
}
|
|
|
|
va_end(ap);
|
|
|
|
cmd = sdscatprintf(cmd,"*%zu\r\n",argslen);
|
|
cmd = sdscatsds(cmd,cmdargs);
|
|
sdsfree(cmdargs);
|
|
|
|
/* Transfer command to the server. */
|
|
if (connSyncWrite(conn,cmd,sdslen(cmd),g_pserver->repl_syncio_timeout*1000)
|
|
== -1)
|
|
{
|
|
sdsfree(cmd);
|
|
return sdscatprintf(sdsempty(),"-Writing to master: %s",
|
|
connGetLastError(conn));
|
|
}
|
|
sdsfree(cmd);
|
|
}
|
|
|
|
/* Read the reply from the g_pserver-> */
|
|
if (flags & SYNC_CMD_READ) {
|
|
char buf[256];
|
|
|
|
if (connSyncReadLine(conn,buf,sizeof(buf),g_pserver->repl_syncio_timeout*1000)
|
|
== -1)
|
|
{
|
|
return sdscatprintf(sdsempty(),"-Reading from master: %s",
|
|
strerror(errno));
|
|
}
|
|
mi->repl_transfer_lastio = g_pserver->unixtime;
|
|
return sdsnew(buf);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/* Try a partial resynchronization with the master if we are about to reconnect.
|
|
* If there is no cached master structure, at least try to issue a
|
|
* "PSYNC ? -1" command in order to trigger a full resync using the PSYNC
|
|
* command in order to obtain the master run id and the master replication
|
|
* global offset.
|
|
*
|
|
* This function is designed to be called from syncWithMaster(), so the
|
|
* following assumptions are made:
|
|
*
|
|
* 1) We pass the function an already connected socket "fd".
|
|
* 2) This function does not close the file descriptor "fd". However in case
|
|
* of successful partial resynchronization, the function will reuse
|
|
* 'fd' as file descriptor of the g_pserver->master client structure.
|
|
*
|
|
* The function is split in two halves: if read_reply is 0, the function
|
|
* writes the PSYNC command on the socket, and a new function call is
|
|
* needed, with read_reply set to 1, in order to read the reply of the
|
|
* command. This is useful in order to support non blocking operations, so
|
|
* that we write, return into the event loop, and read when there are data.
|
|
*
|
|
* When read_reply is 0 the function returns PSYNC_WRITE_ERR if there
|
|
* was a write error, or PSYNC_WAIT_REPLY to signal we need another call
|
|
* with read_reply set to 1. However even when read_reply is set to 1
|
|
* the function may return PSYNC_WAIT_REPLY again to signal there were
|
|
* insufficient data to read to complete its work. We should re-enter
|
|
* into the event loop and wait in such a case.
|
|
*
|
|
* The function returns:
|
|
*
|
|
* PSYNC_CONTINUE: If the PSYNC command succeeded and we can continue.
|
|
* PSYNC_FULLRESYNC: If PSYNC is supported but a full resync is needed.
|
|
* In this case the master run_id and global replication
|
|
* offset is saved.
|
|
* PSYNC_NOT_SUPPORTED: If the server does not understand PSYNC at all and
|
|
* the caller should fall back to SYNC.
|
|
* PSYNC_WRITE_ERROR: There was an error writing the command to the socket.
|
|
* PSYNC_WAIT_REPLY: Call again the function with read_reply set to 1.
|
|
* PSYNC_TRY_LATER: Master is currently in a transient error condition.
|
|
*
|
|
* Notable side effects:
|
|
*
|
|
* 1) As a side effect of the function call the function removes the readable
|
|
* event handler from "fd", unless the return value is PSYNC_WAIT_REPLY.
|
|
* 2) g_pserver->master_initial_offset is set to the right value according
|
|
* to the master reply. This will be used to populate the 'g_pserver->master'
|
|
* structure replication offset.
|
|
*/
|
|
|
|
#define PSYNC_WRITE_ERROR 0
|
|
#define PSYNC_WAIT_REPLY 1
|
|
#define PSYNC_CONTINUE 2
|
|
#define PSYNC_FULLRESYNC 3
|
|
#define PSYNC_NOT_SUPPORTED 4
|
|
#define PSYNC_TRY_LATER 5
|
|
int slaveTryPartialResynchronization(redisMaster *mi, connection *conn, int read_reply) {
|
|
const char *psync_replid;
|
|
char psync_offset[32];
|
|
sds reply;
|
|
|
|
/* Writing half */
|
|
if (!read_reply) {
|
|
/* Initially set master_initial_offset to -1 to mark the current
|
|
* master run_id and offset as not valid. Later if we'll be able to do
|
|
* a FULL resync using the PSYNC command we'll set the offset at the
|
|
* right value, so that this information will be propagated to the
|
|
* client structure representing the master into g_pserver->master. */
|
|
mi->master_initial_offset = -1;
|
|
|
|
if (mi->cached_master && !g_pserver->fActiveReplica) {
|
|
psync_replid = mi->cached_master->replid;
|
|
snprintf(psync_offset,sizeof(psync_offset),"%lld", mi->cached_master->reploff+1);
|
|
serverLog(LL_NOTICE,"Trying a partial resynchronization (request %s:%s).", psync_replid, psync_offset);
|
|
} else {
|
|
serverLog(LL_NOTICE,"Partial resynchronization not possible (no cached master)");
|
|
psync_replid = "?";
|
|
memcpy(psync_offset,"-1",3);
|
|
}
|
|
|
|
/* Issue the PSYNC command */
|
|
reply = sendSynchronousCommand(mi,SYNC_CMD_WRITE,conn,"PSYNC",psync_replid,psync_offset,NULL);
|
|
if (reply != NULL) {
|
|
serverLog(LL_WARNING,"Unable to send PSYNC to master: %s",reply);
|
|
sdsfree(reply);
|
|
connSetReadHandler(conn, NULL);
|
|
return PSYNC_WRITE_ERROR;
|
|
}
|
|
return PSYNC_WAIT_REPLY;
|
|
}
|
|
|
|
/* Reading half */
|
|
reply = sendSynchronousCommand(mi,SYNC_CMD_READ,conn,NULL);
|
|
if (sdslen(reply) == 0) {
|
|
/* The master may send empty newlines after it receives PSYNC
|
|
* and before to reply, just to keep the connection alive. */
|
|
sdsfree(reply);
|
|
return PSYNC_WAIT_REPLY;
|
|
}
|
|
|
|
connSetReadHandler(conn, NULL);
|
|
|
|
if (!strncmp(reply,"+FULLRESYNC",11)) {
|
|
char *replid = NULL, *offset = NULL;
|
|
|
|
/* FULL RESYNC, parse the reply in order to extract the run id
|
|
* and the replication offset. */
|
|
replid = strchr(reply,' ');
|
|
if (replid) {
|
|
replid++;
|
|
offset = strchr(replid,' ');
|
|
if (offset) offset++;
|
|
}
|
|
if (!replid || !offset || (offset-replid-1) != CONFIG_RUN_ID_SIZE) {
|
|
serverLog(LL_WARNING,
|
|
"Master replied with wrong +FULLRESYNC syntax.");
|
|
/* This is an unexpected condition, actually the +FULLRESYNC
|
|
* reply means that the master supports PSYNC, but the reply
|
|
* format seems wrong. To stay safe we blank the master
|
|
* replid to make sure next PSYNCs will fail. */
|
|
memset(mi->master_replid,0,CONFIG_RUN_ID_SIZE+1);
|
|
} else {
|
|
memcpy(mi->master_replid, replid, offset-replid-1);
|
|
mi->master_replid[CONFIG_RUN_ID_SIZE] = '\0';
|
|
mi->master_initial_offset = strtoll(offset,NULL,10);
|
|
serverLog(LL_NOTICE,"Full resync from master: %s:%lld",
|
|
mi->master_replid,
|
|
mi->master_initial_offset);
|
|
}
|
|
/* We are going to full resync, discard the cached master structure. */
|
|
replicationDiscardCachedMaster(mi);
|
|
sdsfree(reply);
|
|
return PSYNC_FULLRESYNC;
|
|
}
|
|
|
|
if (!strncmp(reply,"+CONTINUE",9)) {
|
|
/* Partial resync was accepted. */
|
|
serverLog(LL_NOTICE,
|
|
"Successful partial resynchronization with master.");
|
|
|
|
/* Check the new replication ID advertised by the master. If it
|
|
* changed, we need to set the new ID as primary ID, and set or
|
|
* secondary ID as the old master ID up to the current offset, so
|
|
* that our sub-slaves will be able to PSYNC with us after a
|
|
* disconnection. */
|
|
char *start = reply+10;
|
|
char *end = reply+9;
|
|
while(end[0] != '\r' && end[0] != '\n' && end[0] != '\0') end++;
|
|
if (end-start == CONFIG_RUN_ID_SIZE) {
|
|
char sznew[CONFIG_RUN_ID_SIZE+1];
|
|
memcpy(sznew,start,CONFIG_RUN_ID_SIZE);
|
|
sznew[CONFIG_RUN_ID_SIZE] = '\0';
|
|
|
|
if (strcmp(sznew,mi->cached_master->replid)) {
|
|
/* Master ID changed. */
|
|
serverLog(LL_WARNING,"Master replication ID changed to %s",sznew);
|
|
|
|
/* Set the old ID as our ID2, up to the current offset+1. */
|
|
memcpy(g_pserver->replid2,mi->cached_master->replid,
|
|
sizeof(g_pserver->replid2));
|
|
g_pserver->second_replid_offset = g_pserver->master_repl_offset+1;
|
|
|
|
/* Update the cached master ID and our own primary ID to the
|
|
* new one. */
|
|
memcpy(g_pserver->replid,sznew,sizeof(g_pserver->replid));
|
|
memcpy(mi->cached_master->replid,sznew,sizeof(g_pserver->replid));
|
|
|
|
/* Disconnect all the sub-slaves: they need to be notified. */
|
|
if (!g_pserver->fActiveReplica)
|
|
disconnectSlaves();
|
|
}
|
|
}
|
|
|
|
/* Setup the replication to continue. */
|
|
sdsfree(reply);
|
|
replicationResurrectCachedMaster(mi, conn);
|
|
|
|
/* If this instance was restarted and we read the metadata to
|
|
* PSYNC from the persistence file, our replication backlog could
|
|
* be still not initialized. Create it. */
|
|
if (g_pserver->repl_backlog == NULL) createReplicationBacklog();
|
|
return PSYNC_CONTINUE;
|
|
}
|
|
|
|
/* If we reach this point we received either an error (since the master does
|
|
* not understand PSYNC or because it is in a special state and cannot
|
|
* serve our request), or an unexpected reply from the master.
|
|
*
|
|
* Return PSYNC_NOT_SUPPORTED on errors we don't understand, otherwise
|
|
* return PSYNC_TRY_LATER if we believe this is a transient error. */
|
|
|
|
if (!strncmp(reply,"-NOMASTERLINK",13) ||
|
|
!strncmp(reply,"-LOADING",8))
|
|
{
|
|
serverLog(LL_NOTICE,
|
|
"Master is currently unable to PSYNC "
|
|
"but should be in the future: %s", reply);
|
|
sdsfree(reply);
|
|
return PSYNC_TRY_LATER;
|
|
}
|
|
|
|
if (strncmp(reply,"-ERR",4)) {
|
|
/* If it's not an error, log the unexpected event. */
|
|
serverLog(LL_WARNING,
|
|
"Unexpected reply to PSYNC from master: %s", reply);
|
|
} else {
|
|
serverLog(LL_NOTICE,
|
|
"Master does not support PSYNC or is in "
|
|
"error state (reply: %s)", reply);
|
|
}
|
|
sdsfree(reply);
|
|
replicationDiscardCachedMaster(mi);
|
|
return PSYNC_NOT_SUPPORTED;
|
|
}
|
|
|
|
/* This handler fires when the non blocking connect was able to
|
|
* establish a connection with the master. */
|
|
void syncWithMaster(connection *conn) {
|
|
serverAssert(GlobalLocksAcquired());
|
|
char tmpfile[256] = {0}, *err = NULL;
|
|
int dfd = -1, maxtries = 5;
|
|
int psync_result;
|
|
|
|
redisMaster *mi = (redisMaster*)connGetPrivateData(conn);
|
|
|
|
/* If this event fired after the user turned the instance into a master
|
|
* with SLAVEOF NO ONE we must just return ASAP. */
|
|
if (mi->repl_state == REPL_STATE_NONE) {
|
|
connClose(conn);
|
|
return;
|
|
}
|
|
|
|
/* Check for errors in the socket: after a non blocking connect() we
|
|
* may find that the socket is in error state. */
|
|
if (connGetState(conn) != CONN_STATE_CONNECTED) {
|
|
serverLog(LL_WARNING,"Error condition on socket for SYNC: %s",
|
|
connGetLastError(conn));
|
|
goto error;
|
|
}
|
|
|
|
/* Send a PING to check the master is able to reply without errors. */
|
|
if (mi->repl_state == REPL_STATE_CONNECTING) {
|
|
serverLog(LL_NOTICE,"Non blocking connect for SYNC fired the event.");
|
|
/* Delete the writable event so that the readable event remains
|
|
* registered and we can wait for the PONG reply. */
|
|
connSetReadHandler(conn, syncWithMaster);
|
|
connSetWriteHandler(conn, NULL);
|
|
mi->repl_state = REPL_STATE_RECEIVE_PONG;
|
|
/* Send the PING, don't check for errors at all, we have the timeout
|
|
* that will take care about this. */
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_WRITE,conn,"PING",NULL);
|
|
if (err) goto write_error;
|
|
return;
|
|
}
|
|
|
|
/* Receive the PONG command. */
|
|
if (mi->repl_state == REPL_STATE_RECEIVE_PONG) {
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_READ,conn,NULL);
|
|
|
|
/* We accept only two replies as valid, a positive +PONG reply
|
|
* (we just check for "+") or an authentication error.
|
|
* Note that older versions of Redis replied with "operation not
|
|
* permitted" instead of using a proper error code, so we test
|
|
* both. */
|
|
if (err[0] != '+' &&
|
|
strncmp(err,"-NOAUTH",7) != 0 &&
|
|
strncmp(err,"-ERR operation not permitted",28) != 0)
|
|
{
|
|
serverLog(LL_WARNING,"Error reply to PING from master: '%s'",err);
|
|
sdsfree(err);
|
|
goto error;
|
|
} else {
|
|
serverLog(LL_NOTICE,
|
|
"Master replied to PING, replication can continue...");
|
|
}
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_SEND_AUTH;
|
|
}
|
|
|
|
/* AUTH with the master if required. */
|
|
if (mi->repl_state == REPL_STATE_SEND_AUTH) {
|
|
if (mi->masteruser && mi->masterauth) {
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_WRITE,conn,"AUTH",
|
|
mi->masteruser,mi->masterauth,NULL);
|
|
if (err) goto write_error;
|
|
mi->repl_state = REPL_STATE_RECEIVE_AUTH;
|
|
return;
|
|
} else if (mi->masterauth) {
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_WRITE,conn,"AUTH",mi->masterauth,NULL);
|
|
if (err) goto write_error;
|
|
mi->repl_state = REPL_STATE_RECEIVE_AUTH;
|
|
return;
|
|
} else {
|
|
mi->repl_state = REPL_STATE_SEND_UUID;
|
|
}
|
|
}
|
|
|
|
/* Receive AUTH reply. */
|
|
if (mi->repl_state == REPL_STATE_RECEIVE_AUTH) {
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_READ,conn,NULL);
|
|
if (err[0] == '-') {
|
|
serverLog(LL_WARNING,"Unable to AUTH to MASTER: %s",err);
|
|
sdsfree(err);
|
|
goto error;
|
|
}
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_SEND_UUID;
|
|
}
|
|
|
|
/* Send UUID */
|
|
if (mi->repl_state == REPL_STATE_SEND_UUID) {
|
|
char szUUID[37] = {0};
|
|
memset(mi->master_uuid, 0, UUID_BINARY_LEN);
|
|
uuid_unparse((unsigned char*)cserver.uuid, szUUID);
|
|
err = sendSynchronousCommand(mi, SYNC_CMD_WRITE,conn,"REPLCONF","uuid",szUUID,NULL);
|
|
if (err) goto write_error;
|
|
mi->repl_state = REPL_STATE_RECEIVE_UUID;
|
|
return;
|
|
}
|
|
|
|
/* Receive UUID */
|
|
if (mi->repl_state == REPL_STATE_RECEIVE_UUID) {
|
|
err = sendSynchronousCommand(mi, SYNC_CMD_READ,conn,NULL);
|
|
if (err[0] == '-') {
|
|
serverLog(LL_WARNING, "non-fatal: Master doesn't understand REPLCONF uuid");
|
|
}
|
|
else {
|
|
if (strlen(err) != 37 // 36-byte UUID string and the leading '+'
|
|
|| uuid_parse(err+1, mi->master_uuid) != 0)
|
|
{
|
|
serverLog(LL_WARNING, "Master replied with a UUID we don't understand");
|
|
sdsfree(err);
|
|
goto error;
|
|
}
|
|
}
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_SEND_PORT;
|
|
// fallthrough
|
|
}
|
|
|
|
/* Set the slave port, so that Master's INFO command can list the
|
|
* slave listening port correctly. */
|
|
if (mi->repl_state == REPL_STATE_SEND_PORT) {
|
|
int port;
|
|
if (g_pserver->slave_announce_port) port = g_pserver->slave_announce_port;
|
|
else if (g_pserver->tls_replication && g_pserver->tls_port) port = g_pserver->tls_port;
|
|
else port = g_pserver->port;
|
|
sds portstr = sdsfromlonglong(port);
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_WRITE,conn,"REPLCONF",
|
|
"listening-port",portstr, NULL);
|
|
sdsfree(portstr);
|
|
if (err) goto write_error;
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_RECEIVE_PORT;
|
|
return;
|
|
}
|
|
|
|
/* Receive REPLCONF listening-port reply. */
|
|
if (mi->repl_state == REPL_STATE_RECEIVE_PORT) {
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_READ,conn,NULL);
|
|
/* Ignore the error if any, not all the Redis versions support
|
|
* REPLCONF listening-port. */
|
|
if (err[0] == '-') {
|
|
serverLog(LL_NOTICE,"(Non critical) Master does not understand "
|
|
"REPLCONF listening-port: %s", err);
|
|
}
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_SEND_IP;
|
|
}
|
|
|
|
/* Skip REPLCONF ip-address if there is no replica-announce-ip option set. */
|
|
if (mi->repl_state == REPL_STATE_SEND_IP &&
|
|
g_pserver->slave_announce_ip == NULL)
|
|
{
|
|
mi->repl_state = REPL_STATE_SEND_CAPA;
|
|
}
|
|
|
|
/* Set the slave ip, so that Master's INFO command can list the
|
|
* slave IP address port correctly in case of port forwarding or NAT. */
|
|
if (mi->repl_state == REPL_STATE_SEND_IP) {
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_WRITE,conn,"REPLCONF",
|
|
"ip-address",g_pserver->slave_announce_ip, NULL);
|
|
if (err) goto write_error;
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_RECEIVE_IP;
|
|
return;
|
|
}
|
|
|
|
/* Receive REPLCONF ip-address reply. */
|
|
if (mi->repl_state == REPL_STATE_RECEIVE_IP) {
|
|
err = sendSynchronousCommand(mi,SYNC_CMD_READ,conn,NULL);
|
|
/* Ignore the error if any, not all the Redis versions support
|
|
* REPLCONF listening-port. */
|
|
if (err[0] == '-') {
|
|
serverLog(LL_NOTICE,"(Non critical) Master does not understand "
|
|
"REPLCONF ip-address: %s", err);
|
|
}
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_SEND_CAPA;
|
|
}
|
|
|
|
/* Inform the master of our (replica) capabilities.
|
|
*
|
|
* EOF: supports EOF-style RDB transfer for diskless replication.
|
|
* PSYNC2: supports PSYNC v2, so understands +CONTINUE <new repl ID>.
|
|
*
|
|
* The master will ignore capabilities it does not understand. */
|
|
if (mi->repl_state == REPL_STATE_SEND_CAPA) {
|
|
if (g_pserver->fActiveReplica)
|
|
{
|
|
err = sendSynchronousCommand(mi, SYNC_CMD_WRITE,conn,"REPLCONF",
|
|
"capa","eof","capa","psync2","capa","activeExpire",NULL);
|
|
}
|
|
else
|
|
{
|
|
err = sendSynchronousCommand(mi, SYNC_CMD_WRITE,conn,"REPLCONF",
|
|
"capa","eof","capa","psync2",NULL);
|
|
}
|
|
if (err) goto write_error;
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_RECEIVE_CAPA;
|
|
return;
|
|
}
|
|
|
|
/* Receive CAPA reply. */
|
|
if (mi->repl_state == REPL_STATE_RECEIVE_CAPA) {
|
|
err = sendSynchronousCommand(mi, SYNC_CMD_READ,conn,NULL);
|
|
/* Ignore the error if any, not all the Redis versions support
|
|
* REPLCONF capa. */
|
|
if (err[0] == '-') {
|
|
serverLog(LL_NOTICE,"(Non critical) Master does not understand "
|
|
"REPLCONF capa: %s", err);
|
|
}
|
|
sdsfree(err);
|
|
mi->repl_state = REPL_STATE_SEND_PSYNC;
|
|
}
|
|
|
|
/* Try a partial resynchonization. If we don't have a cached master
|
|
* slaveTryPartialResynchronization() will at least try to use PSYNC
|
|
* to start a full resynchronization so that we get the master run id
|
|
* and the global offset, to try a partial resync at the next
|
|
* reconnection attempt. */
|
|
if (mi->repl_state == REPL_STATE_SEND_PSYNC) {
|
|
if (slaveTryPartialResynchronization(mi,conn,0) == PSYNC_WRITE_ERROR) {
|
|
err = sdsnew("Write error sending the PSYNC command.");
|
|
goto write_error;
|
|
}
|
|
mi->repl_state = REPL_STATE_RECEIVE_PSYNC;
|
|
return;
|
|
}
|
|
|
|
/* If reached this point, we should be in REPL_STATE_RECEIVE_PSYNC. */
|
|
if (mi->repl_state != REPL_STATE_RECEIVE_PSYNC) {
|
|
serverLog(LL_WARNING,"syncWithMaster(): state machine error, "
|
|
"state should be RECEIVE_PSYNC but is %d",
|
|
mi->repl_state);
|
|
goto error;
|
|
}
|
|
|
|
psync_result = slaveTryPartialResynchronization(mi,conn,1);
|
|
if (psync_result == PSYNC_WAIT_REPLY) return; /* Try again later... */
|
|
|
|
/* If the master is in an transient error, we should try to PSYNC
|
|
* from scratch later, so go to the error path. This happens when
|
|
* the server is loading the dataset or is not connected with its
|
|
* master and so forth. */
|
|
if (psync_result == PSYNC_TRY_LATER) goto error;
|
|
|
|
/* Note: if PSYNC does not return WAIT_REPLY, it will take care of
|
|
* uninstalling the read handler from the file descriptor. */
|
|
|
|
if (psync_result == PSYNC_CONTINUE) {
|
|
serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Master accepted a Partial Resynchronization.");
|
|
if (cserver.supervised_mode == SUPERVISED_SYSTEMD) {
|
|
redisCommunicateSystemd("STATUS=MASTER <-> REPLICA sync: Partial Resynchronization accepted. Ready to accept connections.\n");
|
|
redisCommunicateSystemd("READY=1\n");
|
|
}
|
|
return;
|
|
}
|
|
|
|
/* PSYNC failed or is not supported: we want our slaves to resync with us
|
|
* as well, if we have any sub-slaves. The master may transfer us an
|
|
* entirely different data set and we have no way to incrementally feed
|
|
* our slaves after that. */
|
|
if (!g_pserver->fActiveReplica)
|
|
{
|
|
disconnectSlavesExcept(mi->master_uuid); /* Force our slaves to resync with us as well. */
|
|
freeReplicationBacklog(); /* Don't allow our chained slaves to PSYNC. */
|
|
}
|
|
else
|
|
{
|
|
if (listLength(g_pserver->slaves))
|
|
{
|
|
changeReplicationId();
|
|
clearReplicationId2();
|
|
}
|
|
else
|
|
{
|
|
freeReplicationBacklog(); /* Don't allow our chained slaves to PSYNC. */
|
|
}
|
|
}
|
|
|
|
/* Fall back to SYNC if needed. Otherwise psync_result == PSYNC_FULLRESYNC
|
|
* and the g_pserver->master_replid and master_initial_offset are
|
|
* already populated. */
|
|
if (psync_result == PSYNC_NOT_SUPPORTED) {
|
|
serverLog(LL_NOTICE,"Retrying with SYNC...");
|
|
if (connSyncWrite(conn,"SYNC\r\n",6,g_pserver->repl_syncio_timeout*1000) == -1) {
|
|
serverLog(LL_WARNING,"I/O error writing to MASTER: %s",
|
|
strerror(errno));
|
|
goto error;
|
|
}
|
|
}
|
|
|
|
/* Prepare a suitable temp file for bulk transfer */
|
|
if (!useDisklessLoad()) {
|
|
while(maxtries--) {
|
|
auto dt = std::chrono::system_clock::now().time_since_epoch();
|
|
auto dtMillisecond = std::chrono::duration_cast<std::chrono::milliseconds>(dt);
|
|
snprintf(tmpfile,256,
|
|
"temp-%d.%ld.rdb",(int)dtMillisecond.count(),(long int)getpid());
|
|
dfd = open(tmpfile,O_CREAT|O_WRONLY|O_EXCL,0644);
|
|
if (dfd != -1) break;
|
|
sleep(1);
|
|
}
|
|
if (dfd == -1) {
|
|
serverLog(LL_WARNING,"Opening the temp file needed for MASTER <-> REPLICA synchronization: %s",strerror(errno));
|
|
goto error;
|
|
}
|
|
mi->repl_transfer_fd = dfd;
|
|
}
|
|
|
|
/* Setup the non blocking download of the bulk file. */
|
|
if (connSetReadHandler(conn, readSyncBulkPayload)
|
|
== C_ERR)
|
|
{
|
|
char conninfo[CONN_INFO_LEN];
|
|
serverLog(LL_WARNING,
|
|
"Can't create readable event for SYNC: %s (%s)",
|
|
strerror(errno), connGetInfo(conn, conninfo, sizeof(conninfo)));
|
|
goto error;
|
|
}
|
|
|
|
mi->repl_state = REPL_STATE_TRANSFER;
|
|
mi->repl_transfer_size = -1;
|
|
mi->repl_transfer_read = 0;
|
|
mi->repl_transfer_last_fsync_off = 0;
|
|
mi->repl_transfer_lastio = g_pserver->unixtime;
|
|
if (mi->repl_transfer_tmpfile)
|
|
zfree(mi->repl_transfer_tmpfile);
|
|
mi->repl_transfer_tmpfile = zstrdup(tmpfile);
|
|
return;
|
|
|
|
error:
|
|
if (dfd != -1) close(dfd);
|
|
connClose(conn);
|
|
mi->repl_transfer_s = NULL;
|
|
if (mi->repl_transfer_fd != -1)
|
|
close(mi->repl_transfer_fd);
|
|
if (mi->repl_transfer_tmpfile)
|
|
zfree(mi->repl_transfer_tmpfile);
|
|
mi->repl_transfer_tmpfile = NULL;
|
|
mi->repl_transfer_fd = -1;
|
|
mi->repl_state = REPL_STATE_CONNECT;
|
|
return;
|
|
|
|
write_error: /* Handle sendSynchronousCommand(SYNC_CMD_WRITE) errors. */
|
|
serverLog(LL_WARNING,"Sending command to master in replication handshake: %s", err);
|
|
sdsfree(err);
|
|
goto error;
|
|
}
|
|
|
|
int connectWithMaster(redisMaster *mi) {
|
|
mi->repl_transfer_s = g_pserver->tls_replication ? connCreateTLS() : connCreateSocket();
|
|
connSetPrivateData(mi->repl_transfer_s, mi);
|
|
if (connConnect(mi->repl_transfer_s, mi->masterhost, mi->masterport,
|
|
NET_FIRST_BIND_ADDR, syncWithMaster) == C_ERR) {
|
|
int sev = g_pserver->enable_multimaster ? LL_NOTICE : LL_WARNING; // with multimaster its not unheard of to intentiallionall have downed masters
|
|
serverLog(sev,"Unable to connect to MASTER: %s",
|
|
connGetLastError(mi->repl_transfer_s));
|
|
connClose(mi->repl_transfer_s);
|
|
mi->repl_transfer_s = NULL;
|
|
return C_ERR;
|
|
}
|
|
|
|
|
|
mi->repl_transfer_lastio = g_pserver->unixtime;
|
|
mi->repl_state = REPL_STATE_CONNECTING;
|
|
return C_OK;
|
|
}
|
|
|
|
/* This function can be called when a non blocking connection is currently
|
|
* in progress to undo it.
|
|
* Never call this function directly, use cancelReplicationHandshake() instead.
|
|
*/
|
|
void undoConnectWithMaster(redisMaster *mi) {
|
|
connClose(mi->repl_transfer_s);
|
|
mi->repl_transfer_s = NULL;
|
|
}
|
|
|
|
/* Abort the async download of the bulk dataset while SYNC-ing with master.
|
|
* Never call this function directly, use cancelReplicationHandshake() instead.
|
|
*/
|
|
void replicationAbortSyncTransfer(redisMaster *mi) {
|
|
serverAssert(mi->repl_state == REPL_STATE_TRANSFER);
|
|
undoConnectWithMaster(mi);
|
|
if (mi->repl_transfer_fd!=-1) {
|
|
close(mi->repl_transfer_fd);
|
|
unlink(mi->repl_transfer_tmpfile);
|
|
zfree(mi->repl_transfer_tmpfile);
|
|
mi->repl_transfer_tmpfile = NULL;
|
|
mi->repl_transfer_fd = -1;
|
|
}
|
|
}
|
|
|
|
/* This function aborts a non blocking replication attempt if there is one
|
|
* in progress, by canceling the non-blocking connect attempt or
|
|
* the initial bulk transfer.
|
|
*
|
|
* If there was a replication handshake in progress 1 is returned and
|
|
* the replication state (g_pserver->repl_state) set to REPL_STATE_CONNECT.
|
|
*
|
|
* Otherwise zero is returned and no operation is perforemd at all. */
|
|
int cancelReplicationHandshake(redisMaster *mi) {
|
|
if (mi->repl_state == REPL_STATE_TRANSFER) {
|
|
replicationAbortSyncTransfer(mi);
|
|
mi->repl_state = REPL_STATE_CONNECT;
|
|
} else if (mi->repl_state == REPL_STATE_CONNECTING ||
|
|
slaveIsInHandshakeState(mi))
|
|
{
|
|
undoConnectWithMaster(mi);
|
|
mi->repl_state = REPL_STATE_CONNECT;
|
|
} else {
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
/* Set replication to the specified master address and port. */
|
|
struct redisMaster *replicationAddMaster(char *ip, int port) {
|
|
// pre-reqs: We must not already have a replica in the list with the same tuple
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *miCheck = (redisMaster*)listNodeValue(ln);
|
|
if (strcasecmp(miCheck->masterhost, ip)==0 && miCheck->masterport == port)
|
|
return nullptr;
|
|
}
|
|
|
|
// Pre-req satisfied, lets continue
|
|
int was_master = listLength(g_pserver->masters) == 0;
|
|
redisMaster *mi = nullptr;
|
|
if (!g_pserver->enable_multimaster && listLength(g_pserver->masters)) {
|
|
serverAssert(listLength(g_pserver->masters) == 1);
|
|
mi = (redisMaster*)listNodeValue(listFirst(g_pserver->masters));
|
|
}
|
|
else
|
|
{
|
|
mi = (redisMaster*)zcalloc(sizeof(redisMaster), MALLOC_LOCAL);
|
|
initMasterInfo(mi);
|
|
listAddNodeTail(g_pserver->masters, mi);
|
|
}
|
|
|
|
sdsfree(mi->masterhost);
|
|
mi->masterhost = sdsnew(ip);
|
|
mi->masterport = port;
|
|
if (mi->master) {
|
|
if (FCorrectThread(mi->master))
|
|
freeClient(mi->master);
|
|
else
|
|
freeClientAsync(mi->master);
|
|
}
|
|
disconnectAllBlockedClients(); /* Clients blocked in master, now replica. */
|
|
|
|
/* Force our slaves to resync with us as well. They may hopefully be able
|
|
* to partially resync with us, but we can notify the replid change. */
|
|
if (!g_pserver->fActiveReplica)
|
|
disconnectSlaves();
|
|
cancelReplicationHandshake(mi);
|
|
/* Before destroying our master state, create a cached master using
|
|
* our own parameters, to later PSYNC with the new master. */
|
|
if (was_master) {
|
|
replicationDiscardCachedMaster(mi);
|
|
replicationCacheMasterUsingMyself(mi);
|
|
}
|
|
|
|
/* Fire the role change modules event. */
|
|
moduleFireServerEvent(REDISMODULE_EVENT_REPLICATION_ROLE_CHANGED,
|
|
REDISMODULE_EVENT_REPLROLECHANGED_NOW_REPLICA,
|
|
NULL);
|
|
|
|
/* Fire the master link modules event. */
|
|
if (mi->repl_state == REPL_STATE_CONNECTED)
|
|
moduleFireServerEvent(REDISMODULE_EVENT_MASTER_LINK_CHANGE,
|
|
REDISMODULE_SUBEVENT_MASTER_LINK_DOWN,
|
|
NULL);
|
|
|
|
mi->repl_state = REPL_STATE_CONNECT;
|
|
return mi;
|
|
}
|
|
|
|
void freeMasterInfo(redisMaster *mi)
|
|
{
|
|
zfree(mi->masterauth);
|
|
zfree(mi->masteruser);
|
|
if (mi->repl_transfer_tmpfile)
|
|
zfree(mi->repl_transfer_tmpfile);
|
|
delete mi->staleKeyMap;
|
|
if (mi->cached_master != nullptr)
|
|
freeClientAsync(mi->cached_master);
|
|
if (mi->master != nullptr)
|
|
freeClientAsync(mi->master);
|
|
zfree(mi);
|
|
}
|
|
|
|
|
|
/* Cancel replication, setting the instance as a master itself. */
|
|
void replicationUnsetMaster(redisMaster *mi) {
|
|
if (mi->masterhost == NULL) return; /* Nothing to do. */
|
|
|
|
/* Fire the master link modules event. */
|
|
if (mi->repl_state == REPL_STATE_CONNECTED)
|
|
moduleFireServerEvent(REDISMODULE_EVENT_MASTER_LINK_CHANGE,
|
|
REDISMODULE_SUBEVENT_MASTER_LINK_DOWN,
|
|
NULL);
|
|
|
|
sdsfree(mi->masterhost);
|
|
mi->masterhost = NULL;
|
|
if (mi->master) {
|
|
if (FCorrectThread(mi->master))
|
|
freeClient(mi->master);
|
|
else
|
|
freeClientAsync(mi->master);
|
|
}
|
|
replicationDiscardCachedMaster(mi);
|
|
cancelReplicationHandshake(mi);
|
|
/* When a slave is turned into a master, the current replication ID
|
|
* (that was inherited from the master at synchronization time) is
|
|
* used as secondary ID up to the current offset, and a new replication
|
|
* ID is created to continue with a new replication history.
|
|
*
|
|
* NOTE: this function MUST be called after we call
|
|
* freeClient(server.master), since there we adjust the replication
|
|
* offset trimming the final PINGs. See Github issue #7320. */
|
|
shiftReplicationId();
|
|
/* Disconnecting all the slaves is required: we need to inform slaves
|
|
* of the replication ID change (see shiftReplicationId() call). However
|
|
* the slaves will be able to partially resync with us, so it will be
|
|
* a very fast reconnection. */
|
|
if (!g_pserver->fActiveReplica)
|
|
disconnectSlaves();
|
|
mi->repl_state = REPL_STATE_NONE;
|
|
|
|
/* We need to make sure the new master will start the replication stream
|
|
* with a SELECT statement. This is forced after a full resync, but
|
|
* with PSYNC version 2, there is no need for full resync after a
|
|
* master switch. */
|
|
g_pserver->replicaseldb = -1;
|
|
|
|
/* Once we turn from replica to master, we consider the starting time without
|
|
* slaves (that is used to count the replication backlog time to live) as
|
|
* starting from now. Otherwise the backlog will be freed after a
|
|
* failover if slaves do not connect immediately. */
|
|
g_pserver->repl_no_slaves_since = g_pserver->unixtime;
|
|
|
|
listNode *ln = listSearchKey(g_pserver->masters, mi);
|
|
serverAssert(ln != nullptr);
|
|
listDelNode(g_pserver->masters, ln);
|
|
freeMasterInfo(mi);
|
|
|
|
/* Fire the role change modules event. */
|
|
moduleFireServerEvent(REDISMODULE_EVENT_REPLICATION_ROLE_CHANGED,
|
|
REDISMODULE_EVENT_REPLROLECHANGED_NOW_MASTER,
|
|
NULL);
|
|
|
|
/* Restart the AOF subsystem in case we shut it down during a sync when
|
|
* we were still a slave. */
|
|
if (g_pserver->aof_enabled && g_pserver->aof_state == AOF_OFF) restartAOFAfterSYNC();
|
|
}
|
|
|
|
/* This function is called when the replica lose the connection with the
|
|
* master into an unexpected way. */
|
|
void replicationHandleMasterDisconnection(redisMaster *mi) {
|
|
if (mi != nullptr)
|
|
{
|
|
/* Fire the master link modules event. */
|
|
if (mi->repl_state == REPL_STATE_CONNECTED)
|
|
moduleFireServerEvent(REDISMODULE_EVENT_MASTER_LINK_CHANGE,
|
|
REDISMODULE_SUBEVENT_MASTER_LINK_DOWN,
|
|
NULL);
|
|
mi->master = NULL;
|
|
mi->repl_state = REPL_STATE_CONNECT;
|
|
mi->repl_down_since = g_pserver->unixtime;
|
|
/* We lost connection with our master, don't disconnect slaves yet,
|
|
* maybe we'll be able to PSYNC with our master later. We'll disconnect
|
|
* the slaves only if we'll have to do a full resync with our master. */
|
|
}
|
|
}
|
|
|
|
void replicaofCommand(client *c) {
|
|
/* SLAVEOF is not allowed in cluster mode as replication is automatically
|
|
* configured using the current address of the master node. */
|
|
if (g_pserver->cluster_enabled) {
|
|
addReplyError(c,"REPLICAOF not allowed in cluster mode.");
|
|
return;
|
|
}
|
|
|
|
if (c->argc > 3) {
|
|
if (c->argc != 4) {
|
|
addReplyError(c, "Invalid arguments");
|
|
return;
|
|
}
|
|
if (!strcasecmp((const char*)ptrFromObj(c->argv[1]),"remove")) {
|
|
listIter li;
|
|
listNode *ln;
|
|
bool fRemoved = false;
|
|
long port;
|
|
string2l(szFromObj(c->argv[3]), sdslen(szFromObj(c->argv[3])), &port);
|
|
LRestart:
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li))) {
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
if (mi->masterport != port)
|
|
continue;
|
|
if (sdscmp(szFromObj(c->argv[2]), mi->masterhost) == 0) {
|
|
replicationUnsetMaster(mi);
|
|
fRemoved = true;
|
|
goto LRestart;
|
|
}
|
|
}
|
|
if (!fRemoved) {
|
|
addReplyError(c, "Master not found");
|
|
return;
|
|
} else if (listLength(g_pserver->masters) == 0) {
|
|
goto LLogNoMaster;
|
|
}
|
|
}
|
|
} else if (!strcasecmp((const char*)ptrFromObj(c->argv[1]),"no") &&
|
|
!strcasecmp((const char*)ptrFromObj(c->argv[2]),"one")) {
|
|
/* The special host/port combination "NO" "ONE" turns the instance
|
|
* into a master. Otherwise the new master address is set. */
|
|
if (listLength(g_pserver->masters)) {
|
|
while (listLength(g_pserver->masters))
|
|
{
|
|
replicationUnsetMaster((redisMaster*)listNodeValue(listFirst(g_pserver->masters)));
|
|
}
|
|
LLogNoMaster:
|
|
sds client = catClientInfoString(sdsempty(),c);
|
|
serverLog(LL_NOTICE,"MASTER MODE enabled (user request from '%s')",
|
|
client);
|
|
sdsfree(client);
|
|
}
|
|
} else {
|
|
long port;
|
|
|
|
if (c->flags & CLIENT_SLAVE)
|
|
{
|
|
/* If a client is already a replica they cannot run this command,
|
|
* because it involves flushing all replicas (including this
|
|
* client) */
|
|
addReplyError(c, "Command is not valid when client is a replica.");
|
|
return;
|
|
}
|
|
|
|
if ((getLongFromObjectOrReply(c, c->argv[2], &port, NULL) != C_OK))
|
|
return;
|
|
|
|
redisMaster *miNew = replicationAddMaster((char*)ptrFromObj(c->argv[1]), port);
|
|
if (miNew == nullptr)
|
|
{
|
|
// We have a duplicate
|
|
serverLog(LL_NOTICE,"REPLICAOF would result into synchronization "
|
|
"with the master we are already connected "
|
|
"with. No operation performed.");
|
|
addReplySds(c,sdsnew("+OK Already connected to specified "
|
|
"master\r\n"));
|
|
return;
|
|
}
|
|
|
|
sds client = catClientInfoString(sdsempty(),c);
|
|
serverLog(LL_NOTICE,"REPLICAOF %s:%d enabled (user request from '%s')",
|
|
miNew->masterhost, miNew->masterport, client);
|
|
sdsfree(client);
|
|
}
|
|
addReplyAsync(c,shared.ok);
|
|
}
|
|
|
|
/* ROLE command: provide information about the role of the instance
|
|
* (master or replica) and additional information related to replication
|
|
* in an easy to process format. */
|
|
void roleCommand(client *c) {
|
|
if (listLength(g_pserver->masters) == 0) {
|
|
listIter li;
|
|
listNode *ln;
|
|
void *mbcount;
|
|
int slaves = 0;
|
|
|
|
addReplyArrayLen(c,3);
|
|
addReplyBulkCBuffer(c,"master",6);
|
|
addReplyLongLong(c,g_pserver->master_repl_offset);
|
|
mbcount = addReplyDeferredLen(c);
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
char ip[NET_IP_STR_LEN], *slaveip = replica->slave_ip;
|
|
|
|
if (slaveip[0] == '\0') {
|
|
if (connPeerToString(replica->conn,ip,sizeof(ip),NULL) == -1)
|
|
continue;
|
|
slaveip = ip;
|
|
}
|
|
if (replica->replstate != SLAVE_STATE_ONLINE) continue;
|
|
addReplyArrayLen(c,3);
|
|
addReplyBulkCString(c,slaveip);
|
|
addReplyBulkLongLong(c,replica->slave_listening_port);
|
|
addReplyBulkLongLong(c,replica->repl_ack_off+replica->reploff_skipped);
|
|
slaves++;
|
|
}
|
|
setDeferredArrayLen(c,mbcount,slaves);
|
|
} else {
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
|
|
if (listLength(g_pserver->masters) > 1)
|
|
addReplyArrayLen(c,listLength(g_pserver->masters));
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
std::unique_lock<fastlock> lock;
|
|
if (mi->master != nullptr)
|
|
lock = std::unique_lock<fastlock>(mi->master->lock);
|
|
|
|
const char *slavestate = NULL;
|
|
addReplyArrayLen(c,5);
|
|
if (g_pserver->fActiveReplica)
|
|
addReplyBulkCBuffer(c,"active-replica",14);
|
|
else
|
|
addReplyBulkCBuffer(c,"slave",5);
|
|
addReplyBulkCString(c,mi->masterhost);
|
|
addReplyLongLong(c,mi->masterport);
|
|
if (slaveIsInHandshakeState(mi)) {
|
|
slavestate = "handshake";
|
|
} else {
|
|
switch(mi->repl_state) {
|
|
case REPL_STATE_NONE: slavestate = "none"; break;
|
|
case REPL_STATE_CONNECT: slavestate = "connect"; break;
|
|
case REPL_STATE_CONNECTING: slavestate = "connecting"; break;
|
|
case REPL_STATE_TRANSFER: slavestate = "sync"; break;
|
|
case REPL_STATE_CONNECTED: slavestate = "connected"; break;
|
|
default: slavestate = "unknown"; break;
|
|
}
|
|
}
|
|
addReplyBulkCString(c,slavestate);
|
|
addReplyLongLong(c,mi->master ? mi->master->reploff : -1);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Send a REPLCONF ACK command to the master to inform it about the current
|
|
* processed offset. If we are not connected with a master, the command has
|
|
* no effects. */
|
|
void replicationSendAck(redisMaster *mi)
|
|
{
|
|
client *c = mi->master;
|
|
|
|
if (c != NULL) {
|
|
c->flags |= CLIENT_MASTER_FORCE_REPLY;
|
|
addReplyArrayLen(c,3);
|
|
addReplyBulkCString(c,"REPLCONF");
|
|
addReplyBulkCString(c,"ACK");
|
|
addReplyBulkLongLong(c,c->reploff);
|
|
c->flags &= ~CLIENT_MASTER_FORCE_REPLY;
|
|
}
|
|
}
|
|
|
|
/* ---------------------- MASTER CACHING FOR PSYNC -------------------------- */
|
|
|
|
/* In order to implement partial synchronization we need to be able to cache
|
|
* our master's client structure after a transient disconnection.
|
|
* It is cached into g_pserver->cached_master and flushed away using the following
|
|
* functions. */
|
|
|
|
/* This function is called by freeClient() in order to cache the master
|
|
* client structure instead of destroying it. freeClient() will return
|
|
* ASAP after this function returns, so every action needed to avoid problems
|
|
* with a client that is really "suspended" has to be done by this function.
|
|
*
|
|
* The other functions that will deal with the cached master are:
|
|
*
|
|
* replicationDiscardCachedMaster() that will make sure to kill the client
|
|
* as for some reason we don't want to use it in the future.
|
|
*
|
|
* replicationResurrectCachedMaster() that is used after a successful PSYNC
|
|
* handshake in order to reactivate the cached master.
|
|
*/
|
|
void replicationCacheMaster(redisMaster *mi, client *c) {
|
|
serverAssert(mi->master != NULL && mi->cached_master == NULL);
|
|
serverLog(LL_NOTICE,"Caching the disconnected master state.");
|
|
AssertCorrectThread(c);
|
|
std::lock_guard<decltype(c->lock)> clientlock(c->lock);
|
|
|
|
/* Unlink the client from the server structures. */
|
|
unlinkClient(c);
|
|
|
|
/* Reset the master client so that's ready to accept new commands:
|
|
* we want to discard te non processed query buffers and non processed
|
|
* offsets, including pending transactions, already populated arguments,
|
|
* pending outputs to the master. */
|
|
sdsclear(mi->master->querybuf);
|
|
sdsclear(mi->master->pending_querybuf);
|
|
mi->master->read_reploff = mi->master->reploff;
|
|
if (c->flags & CLIENT_MULTI) discardTransaction(c);
|
|
listEmpty(c->reply);
|
|
c->sentlen = 0;
|
|
c->sentlenAsync = 0;
|
|
c->reply_bytes = 0;
|
|
c->bufpos = 0;
|
|
resetClient(c);
|
|
|
|
/* Save the master. g_pserver->master will be set to null later by
|
|
* replicationHandleMasterDisconnection(). */
|
|
mi->cached_master = mi->master;
|
|
|
|
/* Invalidate the Peer ID cache. */
|
|
if (c->peerid) {
|
|
sdsfree(c->peerid);
|
|
c->peerid = NULL;
|
|
}
|
|
|
|
/* Caching the master happens instead of the actual freeClient() call,
|
|
* so make sure to adjust the replication state. This function will
|
|
* also set g_pserver->master to NULL. */
|
|
replicationHandleMasterDisconnection(mi);
|
|
}
|
|
|
|
/* This function is called when a master is turend into a slave, in order to
|
|
* create from scratch a cached master for the new client, that will allow
|
|
* to PSYNC with the slave that was promoted as the new master after a
|
|
* failover.
|
|
*
|
|
* Assuming this instance was previously the master instance of the new master,
|
|
* the new master will accept its replication ID, and potentiall also the
|
|
* current offset if no data was lost during the failover. So we use our
|
|
* current replication ID and offset in order to synthesize a cached master. */
|
|
void replicationCacheMasterUsingMyself(redisMaster *mi) {
|
|
serverLog(LL_NOTICE,
|
|
"Before turning into a replica, using my own master parameters "
|
|
"to synthesize a cached master: I may be able to synchronize with "
|
|
"the new master with just a partial transfer.");
|
|
|
|
if (mi->cached_master != nullptr)
|
|
{
|
|
// This can happen on first load of the RDB, the master we created in config load is stale
|
|
freeClient(mi->cached_master);
|
|
}
|
|
|
|
/* This will be used to populate the field server.master->reploff
|
|
* by replicationCreateMasterClient(). We'll later set the created
|
|
* master as server.cached_master, so the replica will use such
|
|
* offset for PSYNC. */
|
|
mi->master_initial_offset = g_pserver->master_repl_offset;
|
|
|
|
/* The master client we create can be set to any DBID, because
|
|
* the new master will start its replication stream with SELECT. */
|
|
replicationCreateMasterClient(mi,NULL,-1);
|
|
std::lock_guard<decltype(mi->master->lock)> lock(mi->master->lock);
|
|
|
|
/* Use our own ID / offset. */
|
|
memcpy(mi->master->replid, g_pserver->replid, sizeof(g_pserver->replid));
|
|
|
|
/* Set as cached master. */
|
|
unlinkClient(mi->master);
|
|
mi->cached_master = mi->master;
|
|
mi->master = NULL;
|
|
}
|
|
|
|
/* Free a cached master, called when there are no longer the conditions for
|
|
* a partial resync on reconnection. */
|
|
void replicationDiscardCachedMaster(redisMaster *mi) {
|
|
if (mi->cached_master == NULL) return;
|
|
|
|
serverLog(LL_NOTICE,"Discarding previously cached master state.");
|
|
mi->cached_master->flags &= ~CLIENT_MASTER;
|
|
if (FCorrectThread(mi->cached_master))
|
|
freeClient(mi->cached_master);
|
|
else
|
|
freeClientAsync(mi->cached_master);
|
|
mi->cached_master = NULL;
|
|
}
|
|
|
|
/* Turn the cached master into the current master, using the file descriptor
|
|
* passed as argument as the socket for the new master.
|
|
*
|
|
* This function is called when successfully setup a partial resynchronization
|
|
* so the stream of data that we'll receive will start from were this
|
|
* master left. */
|
|
void replicationResurrectCachedMaster(redisMaster *mi, connection *conn) {
|
|
mi->master = mi->cached_master;
|
|
mi->cached_master = NULL;
|
|
mi->master->conn = conn;
|
|
connSetPrivateData(mi->master->conn, mi->master);
|
|
mi->master->flags &= ~(CLIENT_CLOSE_AFTER_REPLY|CLIENT_CLOSE_ASAP);
|
|
mi->master->authenticated = 1;
|
|
mi->master->lastinteraction = g_pserver->unixtime;
|
|
mi->repl_state = REPL_STATE_CONNECTED;
|
|
mi->repl_down_since = 0;
|
|
|
|
/* Normally changing the thread of a client is a BIG NONO,
|
|
but this client was unlinked so its OK here */
|
|
mi->master->iel = serverTL - g_pserver->rgthreadvar; // martial to this thread
|
|
|
|
/* Re-add to the list of clients. */
|
|
linkClient(mi->master);
|
|
serverAssert(connGetPrivateData(mi->master->conn) == mi->master);
|
|
if (connSetReadHandler(mi->master->conn, readQueryFromClient, true)) {
|
|
serverLog(LL_WARNING,"Error resurrecting the cached master, impossible to add the readable handler: %s", strerror(errno));
|
|
freeClientAsync(mi->master); /* Close ASAP. */
|
|
}
|
|
|
|
/* We may also need to install the write handler as well if there is
|
|
* pending data in the write buffers. */
|
|
if (clientHasPendingReplies(mi->master)) {
|
|
if (connSetWriteHandler(mi->master->conn, sendReplyToClient, true)) {
|
|
serverLog(LL_WARNING,"Error resurrecting the cached master, impossible to add the writable handler: %s", strerror(errno));
|
|
freeClientAsync(mi->master); /* Close ASAP. */
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ------------------------- MIN-SLAVES-TO-WRITE --------------------------- */
|
|
|
|
/* This function counts the number of slaves with lag <= min-slaves-max-lag.
|
|
* If the option is active, the server will prevent writes if there are not
|
|
* enough connected slaves with the specified lag (or less). */
|
|
void refreshGoodSlavesCount(void) {
|
|
listIter li;
|
|
listNode *ln;
|
|
int good = 0;
|
|
|
|
if (!g_pserver->repl_min_slaves_to_write ||
|
|
!g_pserver->repl_min_slaves_max_lag) return;
|
|
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
time_t lag = g_pserver->unixtime - replica->repl_ack_time;
|
|
|
|
if (replica->replstate == SLAVE_STATE_ONLINE &&
|
|
lag <= g_pserver->repl_min_slaves_max_lag) good++;
|
|
}
|
|
g_pserver->repl_good_slaves_count = good;
|
|
}
|
|
|
|
/* ----------------------- REPLICATION SCRIPT CACHE --------------------------
|
|
* The goal of this code is to keep track of scripts already sent to every
|
|
* connected replica, in order to be able to replicate EVALSHA as it is without
|
|
* translating it to EVAL every time it is possible.
|
|
*
|
|
* We use a capped collection implemented by a hash table for fast lookup
|
|
* of scripts we can send as EVALSHA, plus a linked list that is used for
|
|
* eviction of the oldest entry when the max number of items is reached.
|
|
*
|
|
* We don't care about taking a different cache for every different replica
|
|
* since to fill the cache again is not very costly, the goal of this code
|
|
* is to avoid that the same big script is trasmitted a big number of times
|
|
* per second wasting bandwidth and processor speed, but it is not a problem
|
|
* if we need to rebuild the cache from scratch from time to time, every used
|
|
* script will need to be transmitted a single time to reappear in the cache.
|
|
*
|
|
* This is how the system works:
|
|
*
|
|
* 1) Every time a new replica connects, we flush the whole script cache.
|
|
* 2) We only send as EVALSHA what was sent to the master as EVALSHA, without
|
|
* trying to convert EVAL into EVALSHA specifically for slaves.
|
|
* 3) Every time we trasmit a script as EVAL to the slaves, we also add the
|
|
* corresponding SHA1 of the script into the cache as we are sure every
|
|
* replica knows about the script starting from now.
|
|
* 4) On SCRIPT FLUSH command, we replicate the command to all the slaves
|
|
* and at the same time flush the script cache.
|
|
* 5) When the last replica disconnects, flush the cache.
|
|
* 6) We handle SCRIPT LOAD as well since that's how scripts are loaded
|
|
* in the master sometimes.
|
|
*/
|
|
|
|
/* Initialize the script cache, only called at startup. */
|
|
void replicationScriptCacheInit(void) {
|
|
g_pserver->repl_scriptcache_size = 10000;
|
|
g_pserver->repl_scriptcache_dict = dictCreate(&replScriptCacheDictType,NULL);
|
|
g_pserver->repl_scriptcache_fifo = listCreate();
|
|
}
|
|
|
|
/* Empty the script cache. Should be called every time we are no longer sure
|
|
* that every replica knows about all the scripts in our set, or when the
|
|
* current AOF "context" is no longer aware of the script. In general we
|
|
* should flush the cache:
|
|
*
|
|
* 1) Every time a new replica reconnects to this master and performs a
|
|
* full SYNC (PSYNC does not require flushing).
|
|
* 2) Every time an AOF rewrite is performed.
|
|
* 3) Every time we are left without slaves at all, and AOF is off, in order
|
|
* to reclaim otherwise unused memory.
|
|
*/
|
|
void replicationScriptCacheFlush(void) {
|
|
dictEmpty(g_pserver->repl_scriptcache_dict,NULL);
|
|
listRelease(g_pserver->repl_scriptcache_fifo);
|
|
g_pserver->repl_scriptcache_fifo = listCreate();
|
|
}
|
|
|
|
/* Add an entry into the script cache, if we reach max number of entries the
|
|
* oldest is removed from the list. */
|
|
void replicationScriptCacheAdd(sds sha1) {
|
|
int retval;
|
|
sds key = sdsdup(sha1);
|
|
|
|
/* Evict oldest. */
|
|
if (listLength(g_pserver->repl_scriptcache_fifo) == g_pserver->repl_scriptcache_size)
|
|
{
|
|
listNode *ln = listLast(g_pserver->repl_scriptcache_fifo);
|
|
sds oldest = (sds)listNodeValue(ln);
|
|
|
|
retval = dictDelete(g_pserver->repl_scriptcache_dict,oldest);
|
|
serverAssert(retval == DICT_OK);
|
|
listDelNode(g_pserver->repl_scriptcache_fifo,ln);
|
|
}
|
|
|
|
/* Add current. */
|
|
retval = dictAdd(g_pserver->repl_scriptcache_dict,key,NULL);
|
|
listAddNodeHead(g_pserver->repl_scriptcache_fifo,key);
|
|
serverAssert(retval == DICT_OK);
|
|
}
|
|
|
|
/* Returns non-zero if the specified entry exists inside the cache, that is,
|
|
* if all the slaves are aware of this script SHA1. */
|
|
int replicationScriptCacheExists(sds sha1) {
|
|
return dictFind(g_pserver->repl_scriptcache_dict,sha1) != NULL;
|
|
}
|
|
|
|
/* ----------------------- SYNCHRONOUS REPLICATION --------------------------
|
|
* Redis synchronous replication design can be summarized in points:
|
|
*
|
|
* - Redis masters have a global replication offset, used by PSYNC.
|
|
* - Master increment the offset every time new commands are sent to slaves.
|
|
* - Slaves ping back masters with the offset processed so far.
|
|
*
|
|
* So synchronous replication adds a new WAIT command in the form:
|
|
*
|
|
* WAIT <num_replicas> <milliseconds_timeout>
|
|
*
|
|
* That returns the number of replicas that processed the query when
|
|
* we finally have at least num_replicas, or when the timeout was
|
|
* reached.
|
|
*
|
|
* The command is implemented in this way:
|
|
*
|
|
* - Every time a client processes a command, we remember the replication
|
|
* offset after sending that command to the slaves.
|
|
* - When WAIT is called, we ask slaves to send an acknowledgement ASAP.
|
|
* The client is blocked at the same time (see blocked.c).
|
|
* - Once we receive enough ACKs for a given offset or when the timeout
|
|
* is reached, the WAIT command is unblocked and the reply sent to the
|
|
* client.
|
|
*/
|
|
|
|
/* This just set a flag so that we broadcast a REPLCONF GETACK command
|
|
* to all the slaves in the beforeSleep() function. Note that this way
|
|
* we "group" all the clients that want to wait for synchronouns replication
|
|
* in a given event loop iteration, and send a single GETACK for them all. */
|
|
void replicationRequestAckFromSlaves(void) {
|
|
g_pserver->get_ack_from_slaves = 1;
|
|
}
|
|
|
|
/* Return the number of slaves that already acknowledged the specified
|
|
* replication offset. */
|
|
int replicationCountAcksByOffset(long long offset) {
|
|
listIter li;
|
|
listNode *ln;
|
|
int count = 0;
|
|
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
|
|
if (replica->replstate != SLAVE_STATE_ONLINE) continue;
|
|
if ((replica->repl_ack_off + replica->reploff_skipped) >= offset) count++;
|
|
}
|
|
return count;
|
|
}
|
|
|
|
/* WAIT for N replicas to acknowledge the processing of our latest
|
|
* write command (and all the previous commands). */
|
|
void waitCommand(client *c) {
|
|
mstime_t timeout;
|
|
long numreplicas, ackreplicas;
|
|
long long offset = c->woff;
|
|
|
|
if (listLength(g_pserver->masters) && !g_pserver->fActiveReplica) {
|
|
addReplyError(c,"WAIT cannot be used with replica instances. Please also note that since Redis 4.0 if a replica is configured to be writable (which is not the default) writes to replicas are just local and are not propagated.");
|
|
return;
|
|
}
|
|
|
|
/* Argument parsing. */
|
|
if (getLongFromObjectOrReply(c,c->argv[1],&numreplicas,NULL) != C_OK)
|
|
return;
|
|
if (getTimeoutFromObjectOrReply(c,c->argv[2],&timeout,UNIT_MILLISECONDS)
|
|
!= C_OK) return;
|
|
|
|
/* First try without blocking at all. */
|
|
ackreplicas = replicationCountAcksByOffset(c->woff);
|
|
if (ackreplicas >= numreplicas || c->flags & CLIENT_MULTI) {
|
|
addReplyLongLong(c,ackreplicas);
|
|
return;
|
|
}
|
|
|
|
/* Otherwise block the client and put it into our list of clients
|
|
* waiting for ack from slaves. */
|
|
c->bpop.timeout = timeout;
|
|
c->bpop.reploffset = offset;
|
|
c->bpop.numreplicas = numreplicas;
|
|
listAddNodeTail(g_pserver->clients_waiting_acks,c);
|
|
blockClient(c,BLOCKED_WAIT);
|
|
|
|
/* Make sure that the server will send an ACK request to all the slaves
|
|
* before returning to the event loop. */
|
|
replicationRequestAckFromSlaves();
|
|
}
|
|
|
|
/* This is called by unblockClient() to perform the blocking op type
|
|
* specific cleanup. We just remove the client from the list of clients
|
|
* waiting for replica acks. Never call it directly, call unblockClient()
|
|
* instead. */
|
|
void unblockClientWaitingReplicas(client *c) {
|
|
listNode *ln = listSearchKey(g_pserver->clients_waiting_acks,c);
|
|
serverAssert(ln != NULL);
|
|
listDelNode(g_pserver->clients_waiting_acks,ln);
|
|
}
|
|
|
|
/* Check if there are clients blocked in WAIT that can be unblocked since
|
|
* we received enough ACKs from slaves. */
|
|
void processClientsWaitingReplicas(void) {
|
|
long long last_offset = 0;
|
|
int last_numreplicas = 0;
|
|
|
|
listIter li;
|
|
listNode *ln;
|
|
|
|
listRewind(g_pserver->clients_waiting_acks,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *c = (client*)ln->value;
|
|
fastlock_lock(&c->lock);
|
|
|
|
/* Every time we find a client that is satisfied for a given
|
|
* offset and number of replicas, we remember it so the next client
|
|
* may be unblocked without calling replicationCountAcksByOffset()
|
|
* if the requested offset / replicas were equal or less. */
|
|
if (last_offset && last_offset > c->bpop.reploffset &&
|
|
last_numreplicas > c->bpop.numreplicas)
|
|
{
|
|
unblockClient(c);
|
|
addReplyLongLongAsync(c,last_numreplicas);
|
|
} else {
|
|
int numreplicas = replicationCountAcksByOffset(c->bpop.reploffset);
|
|
|
|
if (numreplicas >= c->bpop.numreplicas) {
|
|
last_offset = c->bpop.reploffset;
|
|
last_numreplicas = numreplicas;
|
|
unblockClient(c);
|
|
addReplyLongLongAsync(c,numreplicas);
|
|
}
|
|
}
|
|
fastlock_unlock(&c->lock);
|
|
}
|
|
}
|
|
|
|
/* Return the replica replication offset for this instance, that is
|
|
* the offset for which we already processed the master replication stream. */
|
|
long long replicationGetSlaveOffset(redisMaster *mi) {
|
|
long long offset = 0;
|
|
|
|
if (mi != NULL && mi->masterhost != NULL) {
|
|
if (mi->master) {
|
|
offset = mi->master->reploff;
|
|
} else if (mi->cached_master) {
|
|
offset = mi->cached_master->reploff;
|
|
}
|
|
}
|
|
/* offset may be -1 when the master does not support it at all, however
|
|
* this function is designed to return an offset that can express the
|
|
* amount of data processed by the master, so we return a positive
|
|
* integer. */
|
|
if (offset < 0) offset = 0;
|
|
return offset;
|
|
}
|
|
|
|
/* --------------------------- REPLICATION CRON ---------------------------- */
|
|
|
|
/* Replication cron function, called 1 time per second. */
|
|
void replicationCron(void) {
|
|
static long long replication_cron_loops = 0;
|
|
serverAssert(GlobalLocksAcquired());
|
|
listIter liMaster;
|
|
listNode *lnMaster;
|
|
listRewind(g_pserver->masters, &liMaster);
|
|
|
|
bool fInMasterConnection = false;
|
|
while ((lnMaster = listNext(&liMaster)) && !fInMasterConnection)
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(lnMaster);
|
|
if (mi->repl_state != REPL_STATE_NONE && mi->repl_state != REPL_STATE_CONNECTED && mi->repl_state != REPL_STATE_CONNECT) {
|
|
fInMasterConnection = true;
|
|
}
|
|
}
|
|
|
|
bool fConnectionStarted = false;
|
|
listRewind(g_pserver->masters, &liMaster);
|
|
while ((lnMaster = listNext(&liMaster)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(lnMaster);
|
|
|
|
std::unique_lock<decltype(mi->master->lock)> ulock;
|
|
if (mi->master != nullptr)
|
|
ulock = decltype(ulock)(mi->master->lock);
|
|
|
|
/* Non blocking connection timeout? */
|
|
if (mi->masterhost &&
|
|
(mi->repl_state == REPL_STATE_CONNECTING ||
|
|
slaveIsInHandshakeState(mi)) &&
|
|
(time(NULL)-mi->repl_transfer_lastio) > g_pserver->repl_timeout)
|
|
{
|
|
serverLog(LL_WARNING,"Timeout connecting to the MASTER...");
|
|
cancelReplicationHandshake(mi);
|
|
}
|
|
|
|
/* Bulk transfer I/O timeout? */
|
|
if (mi->masterhost && mi->repl_state == REPL_STATE_TRANSFER &&
|
|
(time(NULL)-mi->repl_transfer_lastio) > g_pserver->repl_timeout)
|
|
{
|
|
serverLog(LL_WARNING,"Timeout receiving bulk data from MASTER... If the problem persists try to set the 'repl-timeout' parameter in keydb.conf to a larger value.");
|
|
cancelReplicationHandshake(mi);
|
|
}
|
|
|
|
/* Timed out master when we are an already connected replica? */
|
|
if (mi->masterhost && mi->master && mi->repl_state == REPL_STATE_CONNECTED &&
|
|
(time(NULL)-mi->master->lastinteraction) > g_pserver->repl_timeout)
|
|
{
|
|
serverLog(LL_WARNING,"MASTER timeout: no data nor PING received...");
|
|
if (FCorrectThread(mi->master))
|
|
freeClient(mi->master);
|
|
else
|
|
freeClientAsync(mi->master);
|
|
}
|
|
|
|
/* Check if we should connect to a MASTER */
|
|
if (mi->repl_state == REPL_STATE_CONNECT && !fInMasterConnection) {
|
|
serverLog(LL_NOTICE,"Connecting to MASTER %s:%d",
|
|
mi->masterhost, mi->masterport);
|
|
if (connectWithMaster(mi) == C_OK) {
|
|
serverLog(LL_NOTICE,"MASTER <-> REPLICA sync started");
|
|
}
|
|
fInMasterConnection = true;
|
|
fConnectionStarted = true;
|
|
}
|
|
|
|
/* Send ACK to master from time to time.
|
|
* Note that we do not send periodic acks to masters that don't
|
|
* support PSYNC and replication offsets. */
|
|
if (mi->masterhost && mi->master &&
|
|
!(mi->master->flags & CLIENT_PRE_PSYNC))
|
|
replicationSendAck(mi);
|
|
}
|
|
|
|
if (fConnectionStarted) {
|
|
// If we cancel this handshake we want the next attempt to be a different master
|
|
listRotateHeadToTail(g_pserver->masters);
|
|
}
|
|
|
|
/* If we have attached slaves, PING them from time to time.
|
|
* So slaves can implement an explicit timeout to masters, and will
|
|
* be able to detect a link disconnection even if the TCP connection
|
|
* will not actually go down. */
|
|
listIter li;
|
|
listNode *ln;
|
|
robj *ping_argv[1];
|
|
|
|
/* First, send PING according to ping_slave_period. */
|
|
if ((replication_cron_loops % g_pserver->repl_ping_slave_period) == 0 &&
|
|
listLength(g_pserver->slaves))
|
|
{
|
|
/* Note that we don't send the PING if the clients are paused during
|
|
* a Redis Cluster manual failover: the PING we send will otherwise
|
|
* alter the replication offsets of master and replica, and will no longer
|
|
* match the one stored into 'mf_master_offset' state. */
|
|
int manual_failover_in_progress =
|
|
g_pserver->cluster_enabled &&
|
|
g_pserver->cluster->mf_end &&
|
|
clientsArePaused();
|
|
|
|
if (!manual_failover_in_progress) {
|
|
ping_argv[0] = createStringObject("PING",4);
|
|
replicationFeedSlaves(g_pserver->slaves, g_pserver->replicaseldb,
|
|
ping_argv, 1);
|
|
decrRefCount(ping_argv[0]);
|
|
}
|
|
}
|
|
|
|
/* Second, send a newline to all the slaves in pre-synchronization
|
|
* stage, that is, slaves waiting for the master to create the RDB file.
|
|
*
|
|
* Also send the a newline to all the chained slaves we have, if we lost
|
|
* connection from our master, to keep the slaves aware that their
|
|
* master is online. This is needed since sub-slaves only receive proxied
|
|
* data from top-level masters, so there is no explicit pinging in order
|
|
* to avoid altering the replication offsets. This special out of band
|
|
* pings (newlines) can be sent, they will have no effect in the offset.
|
|
*
|
|
* The newline will be ignored by the replica but will refresh the
|
|
* last interaction timer preventing a timeout. In this case we ignore the
|
|
* ping period and refresh the connection once per second since certain
|
|
* timeouts are set at a few seconds (example: PSYNC response). */
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
|
|
int is_presync =
|
|
(replica->replstate == SLAVE_STATE_WAIT_BGSAVE_START ||
|
|
(replica->replstate == SLAVE_STATE_WAIT_BGSAVE_END &&
|
|
g_pserver->rdb_child_type != RDB_CHILD_TYPE_SOCKET));
|
|
|
|
if (is_presync) {
|
|
connWrite(replica->conn, "\n", 1);
|
|
}
|
|
}
|
|
|
|
/* Disconnect timedout slaves. */
|
|
if (listLength(g_pserver->slaves)) {
|
|
listIter li;
|
|
listNode *ln;
|
|
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
std::unique_lock<fastlock> ul(replica->lock);
|
|
|
|
if (replica->replstate != SLAVE_STATE_ONLINE) continue;
|
|
if (replica->flags & CLIENT_PRE_PSYNC) continue;
|
|
if ((g_pserver->unixtime - replica->repl_ack_time) > g_pserver->repl_timeout)
|
|
{
|
|
serverLog(LL_WARNING, "Disconnecting timedout replica: %s",
|
|
replicationGetSlaveName(replica));
|
|
if (FCorrectThread(replica))
|
|
{
|
|
ul.release();
|
|
if (!freeClient(replica))
|
|
replica->lock.unlock(); // we didn't free so we have undo the lock we just released
|
|
}
|
|
else
|
|
{
|
|
freeClientAsync(replica);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If this is a master without attached slaves and there is a replication
|
|
* backlog active, in order to reclaim memory we can free it after some
|
|
* (configured) time. Note that this cannot be done for slaves: slaves
|
|
* without sub-slaves attached should still accumulate data into the
|
|
* backlog, in order to reply to PSYNC queries if they are turned into
|
|
* masters after a failover. */
|
|
if (listLength(g_pserver->slaves) == 0 && g_pserver->repl_backlog_time_limit &&
|
|
g_pserver->repl_backlog && listLength(g_pserver->masters) == 0)
|
|
{
|
|
time_t idle = g_pserver->unixtime - g_pserver->repl_no_slaves_since;
|
|
|
|
if (idle > g_pserver->repl_backlog_time_limit) {
|
|
/* When we free the backlog, we always use a new
|
|
* replication ID and clear the ID2. This is needed
|
|
* because when there is no backlog, the master_repl_offset
|
|
* is not updated, but we would still retain our replication
|
|
* ID, leading to the following problem:
|
|
*
|
|
* 1. We are a master instance.
|
|
* 2. Our replica is promoted to master. It's repl-id-2 will
|
|
* be the same as our repl-id.
|
|
* 3. We, yet as master, receive some updates, that will not
|
|
* increment the master_repl_offset.
|
|
* 4. Later we are turned into a replica, connect to the new
|
|
* master that will accept our PSYNC request by second
|
|
* replication ID, but there will be data inconsistency
|
|
* because we received writes. */
|
|
changeReplicationId();
|
|
clearReplicationId2();
|
|
freeReplicationBacklog();
|
|
serverLog(LL_NOTICE,
|
|
"Replication backlog freed after %d seconds "
|
|
"without connected replicas.",
|
|
(int) g_pserver->repl_backlog_time_limit);
|
|
}
|
|
}
|
|
|
|
/* If AOF is disabled and we no longer have attached slaves, we can
|
|
* free our Replication Script Cache as there is no need to propagate
|
|
* EVALSHA at all. */
|
|
if (listLength(g_pserver->slaves) == 0 &&
|
|
g_pserver->aof_state == AOF_OFF &&
|
|
listLength(g_pserver->repl_scriptcache_fifo) != 0)
|
|
{
|
|
replicationScriptCacheFlush();
|
|
}
|
|
|
|
/* Start a BGSAVE good for replication if we have slaves in
|
|
* WAIT_BGSAVE_START state.
|
|
*
|
|
* In case of diskless replication, we make sure to wait the specified
|
|
* number of seconds (according to configuration) so that other slaves
|
|
* have the time to arrive before we start streaming. */
|
|
if (!hasActiveChildProcess()) {
|
|
time_t idle, max_idle = 0;
|
|
int slaves_waiting = 0;
|
|
int mincapa = -1;
|
|
listNode *ln;
|
|
listIter li;
|
|
|
|
listRewind(g_pserver->slaves,&li);
|
|
while((ln = listNext(&li))) {
|
|
client *replica = (client*)ln->value;
|
|
if (replica->replstate == SLAVE_STATE_WAIT_BGSAVE_START) {
|
|
idle = g_pserver->unixtime - replica->lastinteraction;
|
|
if (idle > max_idle) max_idle = idle;
|
|
slaves_waiting++;
|
|
mincapa = (mincapa == -1) ? replica->slave_capa :
|
|
(mincapa & replica->slave_capa);
|
|
}
|
|
}
|
|
|
|
if (slaves_waiting &&
|
|
(!g_pserver->repl_diskless_sync ||
|
|
max_idle > g_pserver->repl_diskless_sync_delay))
|
|
{
|
|
/* Start the BGSAVE. The called function may start a
|
|
* BGSAVE with socket target or disk target depending on the
|
|
* configuration and slaves capabilities. */
|
|
startBgsaveForReplication(mincapa);
|
|
}
|
|
}
|
|
|
|
propagateMasterStaleKeys();
|
|
|
|
/* Remove the RDB file used for replication if Redis is not running
|
|
* with any persistence. */
|
|
removeRDBUsedToSyncReplicas();
|
|
|
|
/* Refresh the number of slaves with lag <= min-slaves-max-lag. */
|
|
refreshGoodSlavesCount();
|
|
replication_cron_loops++; /* Incremented with frequency 1 HZ. */
|
|
}
|
|
|
|
int FBrokenLinkToMaster()
|
|
{
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
if (mi->repl_state != REPL_STATE_CONNECTED)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
int FActiveMaster(client *c)
|
|
{
|
|
if (!(c->flags & CLIENT_MASTER))
|
|
return false;
|
|
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
if (mi->master == c)
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
redisMaster *MasterInfoFromClient(client *c)
|
|
{
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
if (mi->master == c || mi->cached_master == c)
|
|
return mi;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
#define REPLAY_MAX_NESTING 64
|
|
class ReplicaNestState
|
|
{
|
|
public:
|
|
bool FPush()
|
|
{
|
|
if (m_cnesting == REPLAY_MAX_NESTING) {
|
|
m_fCancelled = true;
|
|
return false; // overflow
|
|
}
|
|
|
|
if (m_cnesting == 0)
|
|
m_fCancelled = false;
|
|
++m_cnesting;
|
|
return true;
|
|
}
|
|
|
|
void Pop()
|
|
{
|
|
--m_cnesting;
|
|
}
|
|
|
|
void Cancel()
|
|
{
|
|
m_fCancelled = true;
|
|
}
|
|
|
|
bool FCancelled() const
|
|
{
|
|
return m_fCancelled;
|
|
}
|
|
|
|
bool FFirst() const
|
|
{
|
|
return m_cnesting == 1;
|
|
}
|
|
|
|
redisMaster *getMi(client *c)
|
|
{
|
|
if (m_mi == nullptr)
|
|
m_mi = MasterInfoFromClient(c);
|
|
return m_mi;
|
|
}
|
|
|
|
int nesting() const { return m_cnesting; }
|
|
|
|
private:
|
|
int m_cnesting = 0;
|
|
bool m_fCancelled = false;
|
|
redisMaster *m_mi = nullptr;
|
|
};
|
|
|
|
static thread_local std::unique_ptr<ReplicaNestState> s_pstate;
|
|
|
|
bool FInReplicaReplay()
|
|
{
|
|
return s_pstate != nullptr && s_pstate->nesting() > 0;
|
|
}
|
|
|
|
struct RemoteMasterState
|
|
{
|
|
uint64_t mvcc = 0;
|
|
client *cFake = nullptr;
|
|
|
|
~RemoteMasterState()
|
|
{
|
|
aeAcquireLock();
|
|
freeClient(cFake);
|
|
aeReleaseLock();
|
|
}
|
|
};
|
|
|
|
static std::unordered_map<std::string, RemoteMasterState> g_mapremote;
|
|
|
|
void replicaReplayCommand(client *c)
|
|
{
|
|
if (s_pstate == nullptr)
|
|
s_pstate = std::make_unique<ReplicaNestState>();
|
|
|
|
// the replay command contains two arguments:
|
|
// 1: The UUID of the source
|
|
// 2: The raw command buffer to be replayed
|
|
// 3: (OPTIONAL) the database ID the command should apply to
|
|
|
|
if (!(c->flags & CLIENT_MASTER))
|
|
{
|
|
addReplyError(c, "Command must be sent from a master");
|
|
s_pstate->Cancel();
|
|
return;
|
|
}
|
|
|
|
/* First Validate Arguments */
|
|
if (c->argc < 3)
|
|
{
|
|
addReplyError(c, "Invalid number of arguments");
|
|
s_pstate->Cancel();
|
|
return;
|
|
}
|
|
|
|
std::string uuid;
|
|
uuid.resize(UUID_BINARY_LEN);
|
|
if (c->argv[1]->type != OBJ_STRING || sdslen((sds)ptrFromObj(c->argv[1])) != 36
|
|
|| uuid_parse((sds)ptrFromObj(c->argv[1]), (unsigned char*)uuid.data()) != 0)
|
|
{
|
|
addReplyError(c, "Expected UUID arg1");
|
|
s_pstate->Cancel();
|
|
return;
|
|
}
|
|
|
|
if (c->argv[2]->type != OBJ_STRING)
|
|
{
|
|
addReplyError(c, "Expected command buffer arg2");
|
|
s_pstate->Cancel();
|
|
return;
|
|
}
|
|
|
|
if (c->argc >= 4)
|
|
{
|
|
long long db;
|
|
if (getLongLongFromObject(c->argv[3], &db) != C_OK || db >= cserver.dbnum || selectDb(c, (int)db) != C_OK)
|
|
{
|
|
addReplyError(c, "Invalid database ID");
|
|
s_pstate->Cancel();
|
|
return;
|
|
}
|
|
}
|
|
|
|
uint64_t mvcc = 0;
|
|
if (c->argc >= 5)
|
|
{
|
|
if (getUnsignedLongLongFromObject(c->argv[4], &mvcc) != C_OK)
|
|
{
|
|
addReplyError(c, "Invalid MVCC Timestamp");
|
|
s_pstate->Cancel();
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (FSameUuidNoNil((unsigned char*)uuid.data(), cserver.uuid))
|
|
{
|
|
addReply(c, shared.ok);
|
|
s_pstate->Cancel();
|
|
return; // Our own commands have come back to us. Ignore them.
|
|
}
|
|
|
|
if (!s_pstate->FPush())
|
|
return;
|
|
|
|
RemoteMasterState &remoteState = g_mapremote[uuid];
|
|
if (remoteState.cFake == nullptr)
|
|
remoteState.cFake = createClient(nullptr, c->iel);
|
|
else
|
|
remoteState.cFake->iel = c->iel;
|
|
|
|
client *cFake = remoteState.cFake;
|
|
|
|
if (mvcc != 0 && remoteState.mvcc >= mvcc)
|
|
{
|
|
s_pstate->Cancel();
|
|
s_pstate->Pop();
|
|
return;
|
|
}
|
|
|
|
// OK We've recieved a command lets execute
|
|
client *current_clientSave = serverTL->current_client;
|
|
cFake->lock.lock();
|
|
cFake->authenticated = c->authenticated;
|
|
cFake->puser = c->puser;
|
|
cFake->querybuf = sdscatsds(cFake->querybuf,(sds)ptrFromObj(c->argv[2]));
|
|
selectDb(cFake, c->db->id);
|
|
auto ccmdPrev = serverTL->commandsExecuted;
|
|
cFake->flags |= CLIENT_MASTER | CLIENT_PREVENT_REPL_PROP;
|
|
processInputBuffer(cFake, (CMD_CALL_FULL & (~CMD_CALL_PROPAGATE)));
|
|
cFake->flags &= ~(CLIENT_MASTER | CLIENT_PREVENT_REPL_PROP);
|
|
bool fExec = ccmdPrev != serverTL->commandsExecuted;
|
|
cFake->lock.unlock();
|
|
if (cFake->master_error)
|
|
{
|
|
selectDb(c, cFake->db->id);
|
|
freeClient(cFake);
|
|
remoteState.cFake = cFake = nullptr;
|
|
addReplyError(c, "Error in rreplay command, please check logs.");
|
|
}
|
|
if (cFake != nullptr)
|
|
{
|
|
if (fExec || cFake->flags & CLIENT_MULTI)
|
|
{
|
|
addReply(c, shared.ok);
|
|
selectDb(c, cFake->db->id);
|
|
if (mvcc > remoteState.mvcc)
|
|
remoteState.mvcc = mvcc;
|
|
}
|
|
else
|
|
{
|
|
serverLog(LL_WARNING, "Command didn't execute: %s", cFake->buf);
|
|
addReplyError(c, "command did not execute");
|
|
}
|
|
serverAssert(sdslen(cFake->querybuf) == 0);
|
|
}
|
|
serverTL->current_client = current_clientSave;
|
|
|
|
// call() will not propogate this for us, so we do so here
|
|
if (!s_pstate->FCancelled() && s_pstate->FFirst())
|
|
alsoPropagate(cserver.rreplayCommand,c->db->id,c->argv,c->argc,PROPAGATE_AOF|PROPAGATE_REPL);
|
|
|
|
s_pstate->Pop();
|
|
return;
|
|
}
|
|
|
|
void updateMasterAuth()
|
|
{
|
|
listIter li;
|
|
listNode *ln;
|
|
|
|
listRewind(g_pserver->masters, &li);
|
|
while ((ln = listNext(&li)))
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
zfree(mi->masterauth); mi->masterauth = nullptr;
|
|
zfree(mi->masteruser); mi->masteruser = nullptr;
|
|
|
|
if (cserver.default_masterauth)
|
|
mi->masterauth = zstrdup(cserver.default_masterauth);
|
|
if (cserver.default_masteruser)
|
|
mi->masteruser = zstrdup(cserver.default_masteruser);
|
|
}
|
|
}
|
|
|
|
static void propagateMasterStaleKeys()
|
|
{
|
|
listIter li;
|
|
listNode *ln;
|
|
listRewind(g_pserver->masters, &li);
|
|
robj *rgobj[2];
|
|
|
|
rgobj[0] = createEmbeddedStringObject("DEL", 3);
|
|
|
|
while ((ln = listNext(&li)) != nullptr)
|
|
{
|
|
redisMaster *mi = (redisMaster*)listNodeValue(ln);
|
|
if (mi->staleKeyMap != nullptr)
|
|
{
|
|
if (mi->master != nullptr)
|
|
{
|
|
for (auto &pair : *mi->staleKeyMap)
|
|
{
|
|
if (pair.second.empty())
|
|
continue;
|
|
|
|
client *replica = replicaFromMaster(mi);
|
|
if (replica == nullptr)
|
|
continue;
|
|
|
|
for (auto &spkey : pair.second)
|
|
{
|
|
rgobj[1] = spkey.get();
|
|
replicationFeedSlave(replica, pair.first, rgobj, 2, false);
|
|
}
|
|
}
|
|
delete mi->staleKeyMap;
|
|
mi->staleKeyMap = nullptr;
|
|
}
|
|
}
|
|
}
|
|
|
|
decrRefCount(rgobj[0]);
|
|
}
|