The CI report replica will return the error when performing CLUSTER
FAILOVER:
```
-ERR Master is down or failed, please use CLUSTER FAILOVER FORCE
```
This may because the primary state is fail or the cluster connection
is disconnected during the primary pause. In this PR, we added some
waits in wait_for_role, if the role is replica, we will wait for the
replication link and the cluster link to be ok.
Signed-off-by: Binbin <binloveplay1314@qq.com>
We have an assert in propagateNow. If the primary node receives a
CLUSTER UPDATE such as dirty slots during SIGTERM waitting or during
a manual failover pausing or during a client pause, the delKeysInSlot
call will trigger this assert and cause primary crash.
In this case, we added a new server_del_keys_in_slot state just like
client_pause_in_transaction to track the state to avoid the assert
in propagateNow, the dirty slots will be deleted in the end without
affecting the data consistency.
Signed-off-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
For fake clients like the ones used for Lua and modules, we don't
determine TLS in the right way, causing CLUSTER SLOTS from EVAL over TLS
to fail a debug-assert.
This error was introduced when the caching of CLUSTER SLOTS was
introduced, i.e. in 8.0.0.
Signed-off-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
The one in CLUSTER SETSLOT help us keep track of state better,
of course it also can make the test case happy.
The one in gossip process fixes a problem that a replica can
print a log saying it is an empty primary.
Signed-off-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: Ping Xie <pingxie@outlook.com>
The reason is VM_Call will use a fake client without connection,
so we also need to check if c->conn is NULL.
This also affects scripts. If they are called in the script, the
server will crash. Injecting commands into AOF will also cause
startup failure.
Fixes#1054.
Signed-off-by: Binbin <binloveplay1314@qq.com>
Fix timing issue in evaluating `cluster-allow-replica-migration` for replicas
There is a timing bug where the primary and replica have different
`cluster-allow-replica-migration` settings. In issue #970, we found that if
the replica receives `CLUSTER SETSLOT` before the gossip update, it remains
in the original shard. This happens because we only process the
`cluster-allow-replica-migration` flag for primaries during `CLUSTER SETSLOT`.
This commit fixes the issue by also evaluating this flag for replicas in the
`CLUSTER SETSLOT` path, ensuring correct replica migration behavior.
Closes#970
---------
Signed-off-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: Ping Xie <pingxie@outlook.com>
Signed-off-by: Ping Xie <pingxie@google.com>
The node may not be able to initiate an election in time due to
problems with cluster communication. If an election is initiated,
make sure its offset is 0.
Closes#967.
Signed-off-by: Binbin <binloveplay1314@qq.com>
Signed-off-by: Ping Xie <pingxie@google.com>
Maybe partially resolves https://github.com/valkey-io/valkey/issues/952.
The hostnames test relies on an assumption that node zero and node six
don't communicate with each other to test a bunch of behavior in the
handshake stake. This was done by previously dropping all meet packets,
however it seems like there was some case where node zero was sending a
single pong message to node 6, which was partially initializing the
state.
I couldn't track down why this happened, but I adjusted the test to
simply pause node zero which also correctly emulates the state we want
to be in since we're just testing state on node 6, and removes the
chance of errant messages. The test was failing about 5% of the time
locally, and I wasn't able to reproduce a failure with this new
configuration.
---------
Signed-off-by: Madelyn Olson <madelyneolson@gmail.com>
Signed-off-by: Ping Xie <pingxie@google.com>
The reason is the server 3 still have the server 7 as its replica
due to a short wait, the wait is not enough, we should wait for
server loss its replica.
```
*** [err]: valkey-cli make source node ignores NOREPLICAS error when doing the last CLUSTER SETSLOT
Expected '{127.0.0.1 21497 267}' to be equal to '' (context: type eval line 34 cmd {assert_equal [lindex [R 3 role] 2] {}} proc ::test)
```
Signed-off-by: Binbin <binloveplay1314@qq.com>
In standalone mode, when a `-REDIRECT` error occurs, special handling is
required if the client is in the `MULTI` context.
We have adopted the same handling method as the cluster mode:
1. If a command in the transaction encounters a `REDIRECT` at the time
of queuing, the execution of `EXEC` will return an `EXECABORT` error (we
expect the client to redirect and discard the transaction upon receiving
a `REDIRECT`). That is:
```
MULTI ==> +OK
SET x y ==> -REDIRECT
EXEC ==> -EXECABORT
```
2. If all commands are successfully queued (i.e., `QUEUED` results are
received) but a redirect is detected during `EXEC` execution (such as a
primary-replica switch), a `REDIRECT` is returned to instruct the client
to perform a redirect. That is:
```
MULTI ==> +OK
SET x y ==> +QUEUED
failover
EXEC ==> -REDIRECT
```
---------
Signed-off-by: zhaozhao.zz <zhaozhao.zz@alibaba-inc.com>
When reconfiguring sub-replica, there may a case that the sub-replica will
use the old offset and win the election and cause the data loss if the old
primary went down.
In this case, sender is myself's primary, when executing updateShardId,
not only the sender's shard_id is updated, but also the shard_id of
myself is updated, casuing the subsequent areInSameShard check, that is,
the full_sync_required check to fail.
As part of the recent fix of #885, the sub-replica needs to decide whether
a full sync is required or not when switching shards. This shard membership
check is supposed to be done against sub-replica's current shard_id, which
however was lost in this code path. This then leads to sub-replica joining
the other shard with a completely different and incorrect replication history.
This is the only place where replicaof state can be updated on this path
so the most natural fix would be to pull the chain replication reduction
logic into this code block and before the updateShardId call.
This one follow #885 and closes#942.
Signed-off-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: Ping Xie <pingxie@outlook.com>
Fix a bug in isValidAuxChar where valid characters '.' and ':' were
incorrectly included in the banned charset. This issue affected the
validation of auxiliary fields in the nodes.conf file used by Valkey in
cluster mode, particularly when handling IPv4 and IPv6 addresses. The
code now correctly allows '.' and ':' as valid characters, ensuring
proper handling of these fields. Comments were added to clarify the use
of the banned charset.
Related to #736
---------
Signed-off-by: Ping Xie <pingxie@google.com>
In #885, we only add a shutdown path, there is another path
is that the server might got hang by slowlog. This PR added
the pause path coverage to cover it.
Signed-off-by: Binbin <binloveplay1314@qq.com>
The test might be fast enough and then there is no change in the role
causing the test to fail. Adding a wait to avoid the timing issue:
```
*** [err]: valkey-cli make source node ignores NOREPLICAS error when doing the last CLUSTER SETSLOT
Expected '{127.0.0.1 23154 267}' to be equal to '' (context: type eval line 24 cmd {assert_equal [lindex [R 3 role] 2] {}} proc ::test)
```
Signed-off-by: Binbin <binloveplay1314@qq.com>
This fixes#899. In that issue, the primary is cluster-allow-replica-migration no
and its replica is cluster-allow-replica-migration yes.
And during the slot migration:
1. Primary calling blockClientForReplicaAck, waiting its replica.
2. Its replica reconfiguring itself as a replica of other shards due to
replica migration and disconnect from the old primary.
3. The old primary never got the chance to receive the ack, so it got a
timeout and got a NOREPLICAS error.
In this case, the replicas might automatically migrate to another primary,
resulting in the client being unblocked with the NOREPLICAS error. In this
case, since the configuration will eventually propagate itself, we can safely
ignore this error on the source node.
Signed-off-by: Binbin <binloveplay1314@qq.com>
In CLUSTER SETSLOT propagation logic, if the replicas are down, the
client will get block during command processing and then unblock
with `NOREPLICAS Not enough good replicas to write`.
The reason is that all replicas are down (or some are down), but
myself->num_replicas is including all replicas, so the client will
get block and always get timeout.
We should only wait for those online replicas, otherwise the waiting
propagation will always timeout since there are not enough replicas.
The admin can easily check if there are replicas that are down for an
extended period of time. If they decide to move forward anyways, we
should not block it. If a replica failed right before the replication and
was not included in the replication, it would also unlikely win the election.
Signed-off-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: Ping Xie <pingxie@google.com>
Our current replica can initiate a failover without restriction when
it detects that the primary node is offline. This is generally not a
problem. However, consider the following scenarios:
1. In slot migration, a primary loses its last slot and then becomes
a replica. When it is fully synchronized with the new primary, the new
primary downs.
2. In CLUSTER REPLICATE command, a replica becomes a replica of another
primary. When it is fully synchronized with the new primary, the new
primary downs.
In the above scenario, case 1 may cause the empty primary to be elected
as the new primary, resulting in primary data loss. Case 2 may cause the
non-empty replica to be elected as the new primary, resulting in data
loss and confusion.
The reason is that we have cached primary logic, which is used for psync.
In the above scenario, when clusterSetPrimary is called, myself will cache
server.primary in server.cached_primary for psync. In replicationGetReplicaOffset,
we get server.cached_primary->reploff for offset, gossip it and rank it,
which causes the replica to use the old historical offset to initiate
failover, and it get a good rank, initiates election first, and then is
elected as the new primary.
The main problem here is that when the replica has not completed full
sync, it may get the historical offset in replicationGetReplicaOffset.
The fix is to clear cached_primary in these places where full sync is
obviously needed, and let the replica use offset == 0 to participate
in the election. In this way, this unhealthy replica has a worse rank
and is not easy to be elected.
Of course, it is possible that it will be elected with offset == 0.
In the future, we may need to prohibit the replica with offset == 0
from having the right to initiate elections.
Another point worth mentioning, in above cases:
1. In the ROLE command, the replica status will be handshake, and the
offset will be -1.
2. Before this PR, in the CLUSTER SHARD command, the replica status will
be online, and the offset will be the old cached value (which is wrong).
3. After this PR, in the CLUSTER SHARD, the replica status will be loading,
and the offset will be 0.
Signed-off-by: Binbin <binloveplay1314@qq.com>
We have a number of test failures in the empty shard migration which
seem to be related to race conditions in the failover, but could be more
pervasive. For now disable the tests to prevent so many false negative
test failures.
Signed-off-by: Madelyn Olson <madelyneolson@gmail.com>
Adds two new metrics for per-slot statistics, network-bytes-in and
network-bytes-out. The network bytes are inclusive of replication bytes
but exclude other types of network traffic such as clusterbus traffic.
#### network-bytes-in
The metric tracks network ingress bytes under per-slot context, by
reverse calculation of `c->argv_len_sum` and `c->argc`, stored under a
newly introduced field `c->net_input_bytes_curr_cmd`.
#### network-bytes-out
The metric tracks network egress bytes under per-slot context, by
hooking onto COB buffer mutations.
#### sample response
Both metrics are reported under the `CLUSTER SLOT-STATS` command.
```
127.0.0.1:6379> cluster slot-stats slotsrange 0 0
1) 1) (integer) 0
2) 1) "key-count"
2) (integer) 0
3) "cpu-usec"
4) (integer) 0
5) "network-bytes-in"
6) (integer) 0
7) "network-bytes-out"
8) (integer) 0
```
---------
Signed-off-by: Kyle Kim <kimkyle@amazon.com>
Signed-off-by: Madelyn Olson <madelyneolson@gmail.com>
Co-authored-by: Madelyn Olson <madelyneolson@gmail.com>
In some cases, like read more than write scenario, the replication
offset of the replicas are the same. When the primary fails, the
replicas have the same rankings (rank == 0). They issue the election
at the same time (although we have a random 500), the simultaneous
elections may lead to the failure of the election due to quorum.
In clusterGetReplicaRank, when we calculates the rank, if the offsets
are the same, the one with the smaller node name will have a better
rank to avoid this situation.
---------
Signed-off-by: Binbin <binloveplay1314@qq.com>
The metric tracks cpu time in micro-seconds, sharing the same value as
`INFO COMMANDSTATS`, aggregated under per-slot context.
---------
Signed-off-by: Kyle Kim <kimkyle@amazon.com>
Signed-off-by: Madelyn Olson <madelyneolson@gmail.com>
Co-authored-by: Madelyn Olson <madelyneolson@gmail.com>
We will not reset failover_auth_time after setting it, this is used
to check auth_timeout and auth_retry_time, but we should at least
reset it after a successful failover.
Let's assume the following scenario:
1. Two replicas initiate an election.
2. Replica 1 is elected as the primary node, and replica 2 does not have
enough votes.
3. Replica 1 is down, ie the new primary node down again in a short
time.
4. Replica 2 know that the new primary node is down and wants to
initiate
a failover, but because the failover_auth_time of the previous round
has not been reset, it needs to wait for it to time out and then wait
for the next retry time, which will take cluster-node-timeout * 4 times,
this adds a lot of delay.
There is another problem. Like we will set additional random time for
failover_auth_time, such as random 500ms and replicas ranking 1s. If
replica 2 receives PONG from the new primary node before sending the
FAILOVER_AUTH_REQUEST, that is, before the failover_auth_time, it will
change itself to a replica. If the new primary node goes down again at
this time, replica 2 will use the previous failover_auth_time to
initiate
an election instead of going through the logic of random 500ms and
replicas ranking 1s again, which may lead to unexpected consequences
(for example, a low-ranking replica initiates an election and becomes
the new primary node).
That is, we need to reset failover_auth_time at the appropriate time.
When the replica switches to a new primary, we reset it, because the
existing failover_auth_time is already out of date in this case.
---------
Signed-off-by: Binbin <binloveplay1314@qq.com>
Fix#784
Prior to the change, `CLUSTER SHARDS` command processing might pick a
failed primary node which won't have the slot coverage information and
the slots `output` in turn would be empty. This change finds an
appropriate node which has the slot coverage information served by a
given shard and correctly displays it as part of `CLUSTER SHARDS`
output.
Before:
```
1) 1) "slots"
2) (empty array)
3) "nodes"
4) 1) 1) "id"
2) "2936f22a490095a0a851b7956b0a88f2b67a5d44"
...
9) "role"
10) "master"
...
13) "health"
14) "fail"
```
After:
```
1) 1) "slots"
2) 1) 0
2) 5461
3) "nodes"
4) 1) 1) "id"
2) "2936f22a490095a0a851b7956b0a88f2b67a5d44"
...
9) "role"
10) "master"
...
13) "health"
14) "fail"
```
---------
Signed-off-by: Harkrishn Patro <harkrisp@amazon.com>
Fixes a regression introduced in PR #445, which allowed a message from a
replica
to update the slot ownership of its primary. The regression results in a
`replicaof` cycle, causing server crashes due to the cycle detection
assert. The
fix restores the previous behavior where only primary senders can
trigger
`clusterUpdateSlotsConfigWith`.
Additional changes:
* Handling of primaries without slots is obsoleted by new handling of
when a
sender that was a replica announces that it is now a primary.
* Replication loop detection code is unchanged but shifted downwards.
* Some variables are renamed for better readability and some are
introduced to
avoid repeated memcmp() calls.
Fixes#753.
---------
Signed-off-by: Ping Xie <pingxie@google.com>
New configs:
* `cluster-announce-client-ipv4`
* `cluster-announce-client-ipv6`
New module API function:
* `ValkeyModule_GetClusterNodeInfoForClient`, takes a client id and is
otherwise just like its non-ForClient cousin.
If configured, one of these IP addresses are reported to each client in
CLUSTER SLOTS, CLUSTER SHARDS, CLUSTER NODES and redirects, replacing
the IP (`custer-announce-ip` or the auto-detected IP) of each node.
Which one is reported to the client depends on whether the client is
connected over IPv4 or IPv6.
Benefits:
* This allows clients using IPv4 to get the IPv4 addresses of all
cluster nodes and IPv6 clients to get the IPv6 clients.
* This allows the IPs visible to clients to be different to the IPs used
between the cluster nodes due to NAT'ing.
The information is propagated in the cluster bus using new Ping
extensions. (Old nodes without this feature ignore unknown Ping
extensions.)
This adds another dimension to CLUSTER SLOTS reply. It now depends on
the client's use of TLS, the IP address family and RESP version.
Refactoring: The cached connection type definition is moved from
connection.h (it actually has nothing to do with the connection
abstraction) to server.h and is changed to a bitmap, with one bit for
each of TLS, IPv6 and RESP3.
Fixes#337
---------
Signed-off-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
This PR is 1 of 3 PRs intended to achieve the goal of 1 million requests
per second, as detailed by [dan touitou](https://github.com/touitou-dan)
in https://github.com/valkey-io/valkey/issues/22. This PR modifies the
IO threads to be fully asynchronous, which is a first and necessary step
to allow more work offloading and better utilization of the IO threads.
### Current IO threads state:
Valkey IO threads were introduced in Redis 6.0 to allow better
utilization of multi-core machines. Before this, Redis was
single-threaded and could only use one CPU core for network and command
processing. The introduction of IO threads helps in offloading the IO
operations to multiple threads.
**Current IO Threads flow:**
1. Initialization: When Redis starts, it initializes a specified number
of IO threads. These threads are in addition to the main thread, each
thread starts with an empty list, the main thread will populate that
list in each event-loop with pending-read-clients or
pending-write-clients.
2. Read Phase: The main thread accepts incoming connections and reads
requests from clients. The reading of requests are offloaded to IO
threads. The main thread puts the clients ready-to-read in a list and
set the global io_threads_op to IO_THREADS_OP_READ, the IO threads pick
the clients up, perform the read operation and parse the first incoming
command.
3. Command Processing: After reading the requests, command processing is
still single-threaded and handled by the main thread.
4. Write Phase: Similar to the read phase, the write phase is also be
offloaded to IO threads. The main thread prepares the response in the
clients’ output buffer then the main thread puts the client in the list,
and sets the global io_threads_op to the IO_THREADS_OP_WRITE. The IO
threads then pick the clients up and perform the write operation to send
the responses back to clients.
5. Synchronization: The main-thread communicate with the threads on how
many jobs left per each thread with atomic counter. The main-thread
doesn’t access the clients while being handled by the IO threads.
**Issues with current implementation:**
* Underutilized Cores: The current implementation of IO-threads leads to
the underutilization of CPU cores.
* The main thread remains responsible for a significant portion of
IO-related tasks that could be offloaded to IO-threads.
* When the main-thread is processing client’s commands, the IO threads
are idle for a considerable amount of time.
* Notably, the main thread's performance during the IO-related tasks is
constrained by the speed of the slowest IO-thread.
* Limited Offloading: Currently, Since the Main-threads waits
synchronously for the IO threads, the Threads perform only read-parse,
and write operations, with parsing done only for the first command. If
the threads can do work asynchronously we may offload more work to the
threads reducing the load from the main-thread.
* TLS: Currently, we don't support IO threads with TLS (where offloading
IO would be more beneficial) since TLS read/write operations are not
thread-safe with the current implementation.
### Suggested change
Non-blocking main thread - The main thread and IO threads will operate
in parallel to maximize efficiency. The main thread will not be blocked
by IO operations. It will continue to process commands independently of
the IO thread's activities.
**Implementation details**
**Inter-thread communication.**
* We use a static, lock-free ring buffer of fixed size (2048 jobs) for
the main thread to send jobs and for the IO to receive them. If the ring
buffer fills up, the main thread will handle the task itself, acting as
back pressure (in case IO operations are more expensive than command
processing). A static ring buffer is a better candidate than a dynamic
job queue as it eliminates the need for allocation/freeing per job.
* An IO job will be in the format: ` [void* function-call-back | void
*data] `where data is either a client to read/write from and the
function-ptr is the function to be called with the data for example
readQueryFromClient using this format we can use it later to offload
other types of works to the IO threads.
* The Ring buffer is one way from the main-thread to the IO thread, Upon
read/write event the main thread will send a read/write job then in
before sleep it will iterate over the pending read/write clients to
checking for each client if the IO threads has already finished handling
it. The IO thread signals it has finished handling a client read/write
by toggling an atomic flag read_state / write_state on the client
struct.
**Thread Safety**
As suggested in this solution, the IO threads are reading from and
writing to the clients' buffers while the main thread may access those
clients.
We must ensure no race conditions or unsafe access occurs while keeping
the Valkey code simple and lock free.
Minimal Action in the IO Threads
The main change is to limit the IO thread operations to the bare
minimum. The IO thread will access only the client's struct and only the
necessary fields in this struct.
The IO threads will be responsible for the following:
* Read Operation: The IO thread will only read and parse a single
command. It will not update the server stats, handle read errors, or
parsing errors. These tasks will be taken care of by the main thread.
* Write Operation: The IO thread will only write the available data. It
will not free the client's replies, handle write errors, or update the
server statistics.
To achieve this without code duplication, the read/write code has been
refactored into smaller, independent components:
* Functions that perform only the read/parse/write calls.
* Functions that handle the read/parse/write results.
This refactor accounts for the majority of the modifications in this PR.
**Client Struct Safe Access**
As we ensure that the IO threads access memory only within the client
struct, we need to ensure thread safety only for the client's struct's
shared fields.
* Query Buffer
* Command parsing - The main thread will not try to parse a command from
the query buffer when a client is offloaded to the IO thread.
* Client's memory checks in client-cron - The main thread will not
access the client query buffer if it is offloaded and will handle the
querybuf grow/shrink when the client is back.
* CLIENT LIST command - The main thread will busy-wait for the IO thread
to finish handling the client, falling back to the current behavior
where the main thread waits for the IO thread to finish their
processing.
* Output Buffer
* The IO thread will not change the client's bufpos and won't free the
client's reply lists. These actions will be done by the main thread on
the client's return from the IO thread.
* bufpos / block→used: As the main thread may change the bufpos, the
reply-block→used, or add/delete blocks to the reply list while the IO
thread writes, we add two fields to the client struct: io_last_bufpos
and io_last_reply_block. The IO thread will write until the
io_last_bufpos, which was set by the main-thread before sending the
client to the IO thread. If more data has been added to the cob in
between, it will be written in the next write-job. In addition, the main
thread will not trim or merge reply blocks while the client is
offloaded.
* Parsing Fields
* Client's cmd, argc, argv, reqtype, etc., are set during parsing.
* The main thread will indicate to the IO thread not to parse a cmd if
the client is not reset. In this case, the IO thread will only read from
the network and won't attempt to parse a new command.
* The main thread won't access the c→cmd/c→argv in the CLIENT LIST
command as stated before it will busy wait for the IO threads.
* Client Flags
* c→flags, which may be changed by the main thread in multiple places,
won't be accessed by the IO thread. Instead, the main thread will set
the c→io_flags with the information necessary for the IO thread to know
the client's state.
* Client Close
* On freeClient, the main thread will busy wait for the IO thread to
finish processing the client's read/write before proceeding to free the
client.
* Client's Memory Limits
* The IO thread won't handle the qb/cob limits. In case a client crosses
the qb limit, the IO thread will stop reading for it, letting the main
thread know that the client crossed the limit.
**TLS**
TLS is currently not supported with IO threads for the following
reasons:
1. Pending reads - If SSL has pending data that has already been read
from the socket, there is a risk of not calling the read handler again.
To handle this, a list is used to hold the pending clients. With IO
threads, multiple threads can access the list concurrently.
2. Event loop modification - Currently, the TLS code
registers/unregisters the file descriptor from the event loop depending
on the read/write results. With IO threads, multiple threads can modify
the event loop struct simultaneously.
3. The same client can be sent to 2 different threads concurrently
(https://github.com/redis/redis/issues/12540).
Those issues were handled in the current PR:
1. The IO thread only performs the read operation. The main thread will
check for pending reads after the client returns from the IO thread and
will be the only one to access the pending list.
2. The registering/unregistering of events will be similarly postponed
and handled by the main thread only.
3. Each client is being sent to the same dedicated thread (c→id %
num_of_threads).
**Sending Replies Immediately with IO threads.**
Currently, after processing a command, we add the client to the
pending_writes_list. Only after processing all the clients do we send
all the replies. Since the IO threads are now working asynchronously, we
can send the reply immediately after processing the client’s requests,
reducing the command latency. However, if we are using AOF=always, we
must wait for the AOF buffer to be written, in which case we revert to
the current behavior.
**IO threads dynamic adjustment**
Currently, we use an all-or-nothing approach when activating the IO
threads. The current logic is as follows: if the number of pending write
clients is greater than twice the number of threads (including the main
thread), we enable all threads; otherwise, we enable none. For example,
if 8 IO threads are defined, we enable all 8 threads if there are 16
pending clients; else, we enable none.
It makes more sense to enable partial activation of the IO threads. If
we have 10 pending clients, we will enable 5 threads, and so on. This
approach allows for a more granular and efficient allocation of
resources based on the current workload.
In addition, the user will now be able to change the number of I/O
threads at runtime. For example, when decreasing the number of threads
from 4 to 2, threads 3 and 4 will be closed after flushing their job
queues.
**Tests**
Currently, we run the io-threads tests with 4 IO threads
(443d80f168/.github/workflows/daily.yml (L353)).
This means that we will not activate the IO threads unless there are 8
(threads * 2) pending write clients per single loop, which is unlikely
to happened in most of tests, meaning the IO threads are not currently
being tested.
To enforce the main thread to always offload work to the IO threads,
regardless of the number of pending events, we add an
events-per-io-thread configuration with a default value of 2. When set
to 0, this configuration will force the main thread to always offload
work to the IO threads.
When we offload every single read/write operation to the IO threads, the
IO-threads are running with 100% CPU when running multiple tests
concurrently some tests fail as a result of larger than expected command
latencies. To address this issue, we have to add some after or wait_for
calls to some of the tests to ensure they pass with IO threads as well.
Signed-off-by: Uri Yagelnik <uriy@amazon.com>
cluster-slots test is tesing a very fragmented slots range of a
relatively large cluster. For this reason, when run under valgrind, some
of the nodes are timing out when cluster is attempting to converge and
propagate.
This pr sets the test's cluster-node-timeout to 90000 and
cluster-ping-interval to 1000.
Signed-off-by: ranshid <ranshid@amazon.com>
Test failed in my local:
```
*** [err]: CLUSTER SLOT-STATS ORDERBY LIMIT correct response pagination, where limit is less than number of assigned slots in tests/unit/cluster/slot-stats.tcl
Expected [dict exists 0 0 1 0 2 0 3 0 4 0 16383] (context: type source line 64 file /xxx/tests/unit/cluster/slot-stats.tcl cmd {assert {[dict exists $expected_slots $slot]}} proc ::assert_slot_visibility level 1)
```
It seems that when the stat is equal, that is, when the key-count is
equal,
the qsort performance will be different. When the stat is equal, we
compare
by slot (in ascending order).
Signed-off-by: Binbin <binloveplay1314@qq.com>
We did not set a default value for limit, but it will be used
in addReplyOrderBy later, the undefined behavior may crash the
server since the value could be negative and crash will happen
in addReplyArrayLen.
An interesting reproducible example (limit reuses the value of -1):
```
> cluster slot-stats orderby key-count desc limit -1
(error) ERR Limit has to lie in between 1 and 16384 (maximum number of slots).
> cluster slot-stats orderby key-count desc
Error: Server closed the connection
```
Set the default value of limit to 16384.
---------
Signed-off-by: Binbin <binloveplay1314@qq.com>
The command provides detailed slot usage statistics upon invocation,
with initial support for key-count metric. cpu-usec (approved) and
memory-bytes (pending-approval) metrics will soon follow after the
merger of this PR.
---------
Signed-off-by: Kyle Kim <kimkyle@amazon.com>
Signed-off-by: Madelyn Olson <madelyneolson@gmail.com>
Co-authored-by: Madelyn Olson <madelyneolson@gmail.com>
In markNodeAsFailingIfNeeded we will count needed_quorum and failures,
needed_quorum is the half the cluster->size and plus one, and
cluster-size
is the size of primary node which contain slots, but when counting
failures, we dit not check if primary has slots.
Only the primary has slots that has the rights to vote, adding a new
clusterNodeIsVotingPrimary to formalize this concept.
Release notes:
bugfix where nodes not in the quorum group might spuriously mark nodes
as failed
---------
Signed-off-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: Ping Xie <pingxie@outlook.com>
When there is a link failure while an ongoing MEET request is sent the
sending node stops sending anymore MEET and starts sending PINGs. Since
every node responds to PINGs from unknown nodes with a PONG, the
receiving node never adds the sending node. But the sending node adds
the receiving node when it sees a PONG. This can lead to asymmetry in
cluster membership. This changes makes the sender keep sending MEET
until it sees a PONG, avoiding the asymmetry.
---------
Signed-off-by: Sankar <1890648+srgsanky@users.noreply.github.com>
More rebranding of
* Log messages (#252)
* The DENIED error reply
* Internal function names and comments, mainly Lua API
---------
Signed-off-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
"Client blocked on XREADGROUP while stream's slot is migrated" uses the
migrate command, which requires special handling for TLS and non-tls.
This was not being handled, so was throwing an error.
Signed-off-by: Madelyn Olson <madelyneolson@gmail.com>
In #11012, we changed the way command durations were computed to handle
the same command being executed multiple times. In #11970, we added an
assert if the duration is not properly reset, potentially indicating
that a call to report statistics was missed.
I found an edge case where this happens - easily reproduced by blocking
a client on `XGROUPREAD` and migrating the stream's slot. This causes
the engine to process the `XGROUPREAD` command twice:
1. First time, we are blocked on the stream, so we wait for unblock to
come back to it a second time. In most cases, when we come back to
process the command second time after unblock, we process the command
normally, which includes recording the duration and then resetting it.
2. After unblocking we come back to process the command, and this is
where we hit the edge case - at this point, we had already migrated the
slot to another node, so we return a `MOVED` response. But when we do
that, we don’t reset the duration field.
Fix: also reset the duration when returning a `MOVED` response. I think
this is right, because the client should redirect the command to the
right node, which in turn will calculate the execution duration.
Also wrote a test which reproduces this, it fails without the fix and
passes with it.
---------
Signed-off-by: Nitai Caro <caronita@amazon.com>
Co-authored-by: Nitai Caro <caronita@amazon.com>
In #53, we will cache the CLUSTER SLOTS response to improve the
throughput and reduct the latency.
In the code snippet below, the second cluster slots will use the
old hostname:
```
config set cluster-preferred-endpoint-type hostname
config set cluster-announce-hostname old-hostname.com
multi
cluster slots
config set cluster-announce-hostname new-hostname.com
cluster slots
exec
```
When updating the hostname, in updateAnnouncedHostname, we will set
CLUSTER_TODO_SAVE_CONFIG and we will do a clearCachedClusterSlotsResponse
in clusterSaveConfigOrDie, so harmless in most cases.
Move the clearCachedClusterSlotsResponse call to clusterDoBeforeSleep
instead of scheduling it to be called in clusterSaveConfigOrDie.
Signed-off-by: Binbin <binloveplay1314@qq.com>
This aligns the behaviour with established Valkey commands with a
TIMEOUT argument, such as BLPOP.
Fix#422
Signed-off-by: Ping Xie <pingxie@google.com>
After READONLY, make a cluster replica behave as its primary regarding
returning ASK redirects and TRYAGAIN.
Without this patch, a client reading from a replica cannot tell if a key
doesn't exist or if it has already been migrated to another shard as
part of an ongoing slot migration. Therefore, without an ASK redirect in
this situation, offloading reads to cluster replicas wasn't reliable.
Note: The target of a redirect is always a primary. If a client wants to
continue reading from a replica after following a redirect, it needs to
figure out the replicas of that new primary using CLUSTER SHARDS or
similar.
This is related to #21 and has been made possible by the introduction of
Replication of Slot Migration States in #445.
----
Release notes:
During cluster slot migration, replicas are able to return -ASK
redirects and -TRYAGAIN.
---------
Signed-off-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
This commit adds a logic to cache `CLUSTER SLOTS` response for reduced
latency and also updates the cache when a change in the cluster is
detected.
Historically, `CLUSTER SLOTS` command was deprecated, however all the
server clients have been using `CLUSTER SLOTS` and have not migrated to
`CLUSTER SHARDS`. In future this logic can be added to any other
commands to improve the performance of the engine.
---------
Signed-off-by: Roshan Khatri <rvkhatri@amazon.com>
We currently has two disjoint TCL frameworks:
1. Normal testing framework, which trigger by runtest, which individually
launches nodes for testing.
2. Cluster framework, which trigger by runtest-cluster, which pre-allocates
N nodes and uses them for testing large configurations.
The normal TCL testing framework is much more readily tested and is also
automatically run as part of the CI for new PRs. The runtest-cluster since
it runs very slowly (cannot be parallelized), it currently only runs in daily
CI, this results in some changes to the cluster not being exposed in PR CI
in time.
This PR migrate the Cluster mode tests to normal framework. Some cluster
tests are kept in runtest-cluster because of timing issues or not yet
supported, we can process them later.
Signed-off-by: Binbin <binloveplay1314@qq.com>
