This happens only on diskless replicas when attempting to reconnect after
failing to load an RDB file. It is more likely to occur with larger datasets.
After reconnection is initiated, replicationEmptyDbCallback() may get called
and try to write to an unconnected socket. This triggered another issue where
the connection is put into an error state and the connect handler never gets
called. The problem is a regression introduced by commit cad93ed.
When all replicas waiting for a bgsave get disconnected (possibly due to output buffer limit),
It may be good to kill the bgsave child. in diskless replication it already happens, but in
disk-based, the child may still serve some purpose (for persistence).
By killing the child, we prevent it from eating COW memory in vain, and we also allow a new child fork sooner for the next full synchronization or bgsave.
We do that only if rdb persistence wasn't enabled in the configuration.
Btw, now, rdbRemoveTempFile in killRDBChild won't block server, so we can killRDBChild safely.
This commit adds streamIteratorStop call in rewriteStreamObject function in some of the return statement. Although currently this will not cause memory leak since stream id is only 16 bytes long.
Refine comment of makeThreadKillable().
This commit can be backported to 5.0, only if we also backport cf8a6e3.
Co-authored-by: Oran Agra <oran@redislabs.com>
6918ebc introudced a makefile script that detects if the toolchain
supports c11, and it looked that it was passing on MacOS and fails on
Ubuntu, looks like Ubuntu's Dash was spawning a background process,
deleted foo.c before gcc tried to compile it.
We're already using bg_unlink in several places to delete the rdb file in the background,
and avoid paying the cost of the deletion from our main thread.
This commit uses bg_unlink to remove the temporary rdb file in the background too.
However, in case we delete that rdb file just before exiting, we don't actually wait for the
background thread or the main thread to delete it, and just let the OS clean up after us.
i.e. we open the file, unlink it and exit with the fd still open.
Furthermore, rdbRemoveTempFile can be called from a thread and was using snprintf which is
not async-signal-safe, we now use ll2string instead.
Redis 6.0 introduces I/O threads, it is so cool and efficient, we use C11
_Atomic to establish inter-thread synchronization without mutex. But the
compiler that must supports C11 _Atomic can compile redis code, that brings a
lot of inconvenience since some common platforms can't support by default such
as CentOS7, so we want to implement redis atomic type to make it more portable.
We have implemented our atomic variable for redis that only has 'relaxed'
operations in src/atomicvar.h, so we implement some operations with
'sequentially-consistent', just like the default behavior of C11 _Atomic that
can establish inter-thread synchronization. And we replace all uses of C11
_Atomic with redis atomic variable.
Our implementation of redis atomic variable uses C11 _Atomic, __atomic or
__sync macros if available, it supports most common platforms, and we will
detect automatically which feature we use. In Makefile we use a dummy file to
detect if the compiler supports C11 _Atomic. Now for gcc, we can compile redis
code theoretically if your gcc version is not less than 4.1.2(starts to support
__sync_xxx operations). Otherwise, we remove use mutex fallback to implement
redis atomic variable for performance and test. You will get compiling errors
if your compiler doesn't support all features of above.
For cover redis atomic variable tests, we add other CI jobs that build redis on
CentOS6 and CentOS7 and workflow daily jobs that run the tests on them.
For them, we just install gcc by default in order to cover different compiler
versions, gcc is 4.4.7 by default installation on CentOS6 and 4.8.5 on CentOS7.
We restore the feature that we can test redis with Helgrind to find data race
errors. But you need install Valgrind in the default path configuration firstly
before running your tests, since we use macros in helgrind.h to tell Helgrind
inter-thread happens-before relationship explicitly for avoiding false positives.
Please open an issue on github if you find data race errors relate to this commit.
Unrelated:
- Fix redefinition of typedef 'RedisModuleUserChangedFunc'
For some old version compilers, they will report errors or warnings, if we
re-define function type.
If one thread got SIGSEGV, function sigsegvHandler() would be triggered,
it would call bioKillThreads(). But call pthread_cancel() to cancel itself
would make it block. Also note that if SIGSEGV is caught by bio thread, it
should kill the main thread in order to give a positive report.
Rather than blindly evicting until maxmemory limit is achieved, this
update adds a time limit to eviction. While over the maxmemory limit,
eviction will process before each command AND as a timeProc when no
commands are running.
This will reduce the latency impact on many cases, especially pathological
cases like massive used memory increase during dict rehashing.
There is a risk that some other edge cases (like massive pipelined use
of MGET) could cause Redis memory usage to keep growing despite the
eviction attempts, so a new maxmemory-eviction-tenacity config is
introduced to let users mitigate that.
This commit makes stream object returning "stream" as encoding type in OBJECT ENCODING subcommand and DEBUG OBJECT command.
Till now, it would return "unknown"
Co-authored-by: Yossi Gottlieb <yossigo@gmail.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
(cherry picked from commit b1de173ec0f6a03d6083b87f1505fbf843708685)
This is a catch-all test to confirm that that rewrite produces a valid
output for all parameters and that this process does not introduce
undesired configuration changes.
(cherry picked from commit 995f1fc53f7daf3d289d5d70d7b45cdd486dc6cc)
Improve RM_Call inline documentation about the fmt argument
so that we don't completely depend on the web docs.
Co-authored-by: Oran Agra <oran@redislabs.com>
(cherry picked from commit c13fa0aa3619c595f06e191a30710d85a109ad48)
THP can also be set to madvise, in which case it shouldn't cause
problems for Redis since redis (or the allocator) doesn't use madvise
to activate it.
(cherry picked from commit 60097d361d4096d3826c7580acffd4053f8a4835)
There was a bug. Although cluster replicas would allow read commands,
they would not allow a MULTI-EXEC that's composed solely of read commands.
Adds tests for coverage.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Eran Liberty <eranl@amazon.com>
(cherry picked from commit 7bee51bb5b2cccbaae76f4721761880acf4d5a93)
Fix issues with writeConn() which resulted with corruption of the stream by leaving an extra byte in the buffer. The trigger for this is partial writes or write errors which were not experienced on Linux but reported on macOS.
(cherry picked from commit 94cd74e5deb18e0383bcad5c596c72980e5350b6)
When redis isn't configured to have a log file, having these prints
before damonization puts them in the calling process stdout rather than
/dev/null
(cherry picked from commit 0db61f564991ad483e2a2014738f25628584476b)
