In the long term we may want to move away from anet completely and have
everything implemented natively in connection.c, instead of having an
extra layer.
For now, just get rid of unused code.
This is both a bugfix and an enhancement.
Internally, Sentinel relies entirely on IP addresses to identify
instances. When configured with a new master, it also requires users to
specify and IP and not hostname.
However, replicas may use the replica-announce-ip configuration to
announce a hostname. When that happens, Sentinel fails to match the
announced hostname with the expected IP and considers that a different
instance, triggering reconfiguration, etc.
Another use case is where TLS is used and clients are expected to match
the hostname to connect to with the certificate's SAN attribute. To
properly implement this configuration, it is necessary for Sentinel to
redirect clients to a hostname rather than an IP address.
The new 'resolve-hostnames' configuration parameter determines if
Sentinel is willing to accept hostnames. It is set by default to no,
which maintains backwards compatibility and avoids unexpected DNS
resolution delays on systems with DNS configuration issues.
Internally, Sentinel continues to identify instances by their resolved
IP address and will also report the IP by default. The new
'announce-hostnames' parameter determines if Sentinel should prefer to
announce a hostname, when available, rather than an IP address. This
applies to addresses returned to clients, as well as their
representation in the configuration file, REPLICAOF configuration
commands, etc.
This commit also introduces SENTINEL CONFIG GET and SENTINEL CONFIG SET
which can be used to introspect or configure global Sentinel
configuration that was previously was only possible by directly
accessing the configuration file and possibly restarting the instance.
Co-authored-by: myl1024 <myl92916@qq.com>
Co-authored-by: sundb <sundbcn@gmail.com>
Sentinel uses execve to run scripts, so it needs to use FD_CLOEXEC
on all file descriptors, so that they're not accessible by the script it runs.
This commit includes a change to the sentinel tests, which verifies no
FDs are left opened when the script is executed.
Useful when you want to know through which bind address the client connected to
the server in case of multiple bind addresses.
- Adding `laddr` field to CLIENT list showing the local (bind) address.
- Adding `LADDR` option to CLIENT KILL to kill all the clients connected
to a specific local address.
- Refactoring to share code.
* Introduce a connection abstraction layer for all socket operations and
integrate it across the code base.
* Provide an optional TLS connections implementation based on OpenSSL.
* Pull a newer version of hiredis with TLS support.
* Tests, redis-cli updates for TLS support.
The implementation of the diskless replication was currently diskless only on the master side.
The slave side was still storing the received rdb file to the disk before loading it back in and parsing it.
This commit adds two modes to load rdb directly from socket:
1) when-empty
2) using "swapdb"
the third mode of using diskless slave by flushdb is risky and currently not included.
other changes:
--------------
distinguish between aof configuration and state so that we can re-enable aof only when sync eventually
succeeds (and not when exiting from readSyncBulkPayload after a failed attempt)
also a CONFIG GET and INFO during rdb loading would have lied
When loading rdb from the network, don't kill the server on short read (that can be a network error)
Fix rdb check when performed on preamble AOF
tests:
run replication tests for diskless slave too
make replication test a bit more aggressive
Add test for diskless load swapdb
This fix was suggested by Anthony LaTorre, that provided also a good
test case that was used to verify the fix.
The problem with the old implementation is that, the time returned by
a timer event (that is the time after it want to run again) is added
to the event *start time*. So if the event takes, in order to run, more
than the time it says it want to be scheduled again for running, an
infinite loop is triggered.
This performs a best effort source address binding attempt. If it is
possible to bind the local address and still have a successful
connect(), then this socket is returned. Otherwise the call is retried
without source address binding attempt.
Related to issues #2609 and #2612.
The first address specified as a bind parameter
(server.bindaddr[0]) gets used as the source IP
for cluster communication.
If no bind address is specified by the user, the
behavior is unchanged.
This patch allows multiple Redis Cluster instances
to communicate when running on the same interface
of the same host.
In high RPS environments, the default listen backlog is not sufficient, so
giving users the power to configure it is the right approach, especially
since it requires only minor modifications to the code.
The new function is used when we want to normalize an IP address without
performing a DNS lookup if the string to resolve is not a valid IP.
This is useful every time only IPs are valid inputs or when we want to
skip DNS resolution that is slow during runtime operations if we are
required to block.
This has been done by exposing the anetSockName() function anet.c
to be used when the sentinel is publishing its existence to the masters.
This implementation is very unintelligent as it will likely break if used
with IPv6 as the nested colons will break any parsing of the PUBLISH string
by the master.
Replace inet_ntoa(3) calls with the more future proof inet_ntop(3)
function which is capable of handling additional address families.
API Change: anetTcpAccept() & anetPeerToString() additional argument
additional argument required to specify the length of the character
buffer the IP address is written to in order to comply with
inet_ntop(3) function semantics.
Change anetResolve() function to use getaddrinfo(3) to resolve hostnames.
Resolved hostnames are limited to those reachable by the AF_INET address
family.
API Change: anetResolve requires additional argument.
additional argument required to specify the length of the character
buffer the IP address is written to in order to comply with
inet_ntop(3) function semantics. inet_ntop(3) replaces inet_ntoa(3)
as it has been designed to be compatible with more address families.
Bind() can't be called multiple times against the same socket, multiple
sockets are required to bind multiple interfaces, silly me.
This reverts commit e0be252d5ea895ed0adb43d8d14f2bee233c6953.
Further details from @antirez:
It was reported by @StopForumSpam on Twitter that the Redis replication
link was strangely using multiple TCP packets for multiple commands.
This wastes a lot of bandwidth and is due to the TCP_NODELAY option we
enable on the socket after accepting a new connection.
However the master -> slave channel is a one-way channel since Redis
replication is asynchronous, so there is no point in trying to reduce
the latency, we should aim to reduce the bandwidth. For this reason this
commit introduces the ability to disable the nagle algorithm on the
socket after a successful SYNC.
This feature is off by default because the delay can be up to 40
milliseconds with normally configured Linux kernels.
Added a configuration directive to allow a user to specify the
permissions to be granted to the Unix socket file. I followed
the format Pieter and Salvatore discusses in issue #85 (
https://github.com/antirez/redis/issues/85).
networking related stuff moved into networking.c
moved more code
more work on layout of source code
SDS instantaneuos memory saving. By Pieter and Salvatore at VMware ;)
cleanly compiling again after the first split, now splitting it in more C files
moving more things around... work in progress
split replication code
splitting more
Sets split
Hash split
replication split
even more splitting
more splitting
minor change
