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.
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.
This test was nearly always failing on MacOS github actions.
This is because of bugs in the test that caused it to nearly always run
all 3 attempts and just look at the last one as the pass/fail creteria.
i.e. the test was nearly always running all 3 attempts and still sometimes
succeed. this is because the break condition was different than the test
completion condition.
The reason the test succeeded is because the break condition tested the
results of all 3 tests (PSETEX/PEXPIRE/PEXPIREAT), but the success check
at the end was only testing the result of PSETEX.
The reason the PEXPIREAT test nearly always failed is because it was
getting the current time wrong: getting the current second and loosing
the sub-section time, so the only chance for it to succeed is if it run
right when a certain second started.
Because i now get the time from redis, adding another round trip, i
added another 100ms to the PEXPIRE test to make it less fragile, and
also added many more attempts.
Adding many more attempts before failure to account for slow platforms,
github actions and valgrind
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.
Save parameters should either be default or whatever specified in the
config file. This fixes an issue introduced in #7092 which causes
configuration file settings to be applied on top of the defaults.
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>
if there are nested tests and nested servers, we need to restore the
previous value of cur_test when a test exist.
example:
```
test{test 1} {
start_server {
test{test 1.1 - master only} {
}
start_server {
test{test 1.2 - with replication} {
}
}
}
}
```
when `test 1.1 - master only exists`, we're still inside `test 1`
1) cur_test: when restart_server, "no such variable" error occurs
./runtest --single integration/rdb
test {client freed during loading}
SET ::cur_test
restart_server
kill_server
test "Check for memory leaks (pid $pid)"
SET ::cur_test
UNSET ::cur_test
UNSET ::cur_test // This global variable has been unset.
2) `ps --ppid` not available on macOS platform, can be replaced with
`pgrep -P pid`.
This test was failing from time to time see discussion at the bottom of #7635
This was probably due to timing, the DEBUG SLEEP executed by redis-cli
didn't sleep for enough time.
This commit changes:
1) use SET-ACTIVE-EXPIRE instead of DEBUG SLEEP
2) reduce many `after` sleeps with retry loops to speed up the test.
3) add many comment explaining the different steps of the test and
it's purpose.
4) config appendonly before populating the volatile keys, so that they'll
be part of the AOF command stream rather than the preamble RDB portion.
other complications: recently kill_instance switched from SIGKILL to
SIGTERM, and this would sometimes fail since there was an AOFRW running
in the background. now we wait for it to end before attempting the kill.
There is an inherent race condition in port allocation for spawned
servers. If a server fails to start because a port is taken, a new port
is allocated. This fixes a problem where the logs are not truncated and
as a result a large number of unmonitored servers are started.
2b998de46 added a file for stderr to keep valgrind log but i forgot to
add a similar thing when valgrind isn't being used.
the result is that `glob */err.txt` fails.
Starting redis 6.0 and the changes we made to the diskless master to be
suitable for TLS, I made the master avoid reaping (wait3) the pid of the
child until we know all replicas are done reading their rdb.
I did that in order to avoid a state where the rdb_child_pid is -1 but
we don't yet want to start another fork (still busy serving that data to
replicas).
It turns out that the solution used so far was problematic in case the
fork child was being killed (e.g. by the kernel OOM killer), in that
case there's a chance that we currently disabled the read event on the
rdb pipe, since we're waiting for a replica to become writable again.
and in that scenario the master would have never realized the child
exited, and the replica will remain hung too.
Note that there's no mechanism to detect a hung replica while it's in
rdb transfer state.
The solution here is to add another pipe which is used by the parent to
tell the child it is safe to exit. this mean that when the child exits,
for whatever reason, it is safe to reap it.
Besides that, i'm re-introducing an adjustment to REPLCONF ACK which was
part of #6271 (Accelerate diskless master connections) but was dropped
when that PR was rebased after the TLS fork/pipe changes (5a47794).
Now that RdbPipeCleanup no longer calls checkChildrenDone, and the ACK
has chance to detect that the child exited, it should be the one to call
it so that we don't have to wait for cron (server.hz) to do that.
- redirect valgrind reports to a dedicated file rather than console
- try to avoid killing instances with SIGKILL so that we get the memory
leak report (killing with SIGTERM before resorting to SIGKILL)
- search for valgrind reports when done, print them and fail the tests
- add --dont-clean option to keep the logs on exit
- fix exit error code when crash is found (would have exited with 0)
changes that affect the normal redis test suite:
- refactor check_valgrind_errors into two functions one to search and
one to report
- move the search half into util.tcl to serve the cluster tests too
- ignore "address range perms" valgrind warnings which seem non relevant.
in some cases a command that returns an error possibly due to a timing
issue causes the tcl code to crash and thus prevents the rest of the
tests from running. this adds an option to make the test proceed despite
the crash.
maybe it should be the default mode some day.
- skip full units
- skip a single test (not just a list of tests)
- when skipping tag, skip spinning up servers, not just the tests
- skip tags when running against an external server too
- allow using multiple tags (split them)
During long running scripts or loading RDB/AOF, we may need to do some
defragging. Since processEventsWhileBlocked is called periodically at
unknown intervals, and many cron jobs either depend on run_with_period
(including active defrag), or rely on being called at server.hz rate
(i.e. active defrag knows ho much time to run by looking at server.hz),
the whileBlockedCron may have to run a loop triggering the cron jobs in it
(currently only active defrag) several times.
Other changes:
- Adding a test for defrag during aof loading.
- Changing key-load-delay config to take negative values for fractions
of a microsecond sleep
If the server gets MULTI command followed by only read
commands, and right before it gets the EXEC it reaches OOM,
the client will get OOM response.
So, from now on, it will get OOM response only if there was
at least one command that was tagged with `use-memory` flag
When calling to LPOS command when RANK is higher than matches,
the return value is non valid response. For example:
```
LPUSH l a
:1
LPOS l b RANK 5 COUNT 10
*-4
```
It may break client-side parser.
Now, we count how many replies were replied in the array.
```
LPUSH l a
:1
LPOS l b RANK 5 COUNT 10
*0
```
After fork, the child process(redis-aof-rewrite) will get the fd opened
by the parent process(redis), when redis killed by kill -9, it will not
graceful exit(call prepareForShutdown()), so redis-aof-rewrite thread may still
alive, the fd(lock) will still be held by redis-aof-rewrite thread, and
redis restart will fail to get lock, means fail to start.
This issue was causing failures in the cluster tests in github actions.
Co-authored-by: Oran Agra <oran@redislabs.com>
Add Linux kernel OOM killer control option.
This adds the ability to control the Linux OOM killer oom_score_adj
parameter for all Redis processes, depending on the process role (i.e.
master, replica, background child).
A oom-score-adj global boolean flag control this feature. In addition,
specific values can be configured using oom-score-adj-values if
additional tuning is required.
This is a rebased version of #3078 originally by shaharmor
with the following patches by TysonAndre made after rebasing
to work with the updated C API:
1. Add 2 more unit tests
(wrong argument count error message, integer over 64 bits)
2. Use addReplyArrayLen instead of addReplyMultiBulkLen.
3. Undo changes to src/help.h - for the ZMSCORE PR,
I heard those should instead be automatically
generated from the redis-doc repo if it gets updated
Motivations:
- Example use case: Client code to efficiently check if each element of a set
of 1000 items is a member of a set of 10 million items.
(Similar to reasons for working on #7593)
- HMGET and ZMSCORE already exist. This may lead to developers deciding
to implement functionality that's best suited to a regular set with a
data type of sorted set or hash map instead, for the multi-get support.
Currently, multi commands or lua scripting to call sismember multiple times
would almost definitely be less efficient than a native smismember
for the following reasons:
- Need to fetch the set from the string every time
instead of reusing the C pointer.
- Using pipelining or multi-commands would result in more bytes sent
and received by the client for the repeated SISMEMBER KEY sections.
- Need to specially encode the data and decode it from the client
for lua-based solutions.
- Proposed solutions using Lua or SADD/SDIFF could trigger writes to
memory, which is undesirable on a redis replica server
or when commands get replicated to replicas.
Co-Authored-By: Shahar Mor <shahar@peer5.com>
Co-Authored-By: Tyson Andre <tysonandre775@hotmail.com>
Added RedisModule_HoldString that either returns a
shallow copy of the given String (by increasing
the String ref count) or a new deep copy of String
in case its not possible to get a shallow copy.
Co-authored-by: Itamar Haber <itamar@redislabs.com>
When runtest-cluster, at first, we need to create a cluster use spawn_instance,
a port which is not used is choosen, however sometimes we can't run server on
the port. possibley due to a race with another process taking it first.
such as redis/redis/runs/896537490. It may be due to the machine problem or
In order to reduce the probability of failure when start redis in
runtest-cluster, we attemp to use another port when find server do not start up.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: yanhui13 <yanhui13@meituan.com>
Diskless master has some inherent latencies.
1) fork starts with delay from cron rather than immediately
2) replica is put online only after an ACK. but the ACK
was sent only once a second.
3) but even if it would arrive immediately, it will not
register in case cron didn't yet detect that the fork is done.
Besides that, when a replica disconnects, it doesn't immediately
attempts to re-connect, it waits for replication cron (one per second).
in case it was already online, it may be important to try to re-connect
as soon as possible, so that the backlog at the master doesn't vanish.
In case it disconnected during rdb transfer, one can argue that it's
not very important to re-connect immediately, but this is needed for the
"diskless loading short read" test to be able to run 100 iterations in 5
seconds, rather than 3 (waiting for replication cron re-connection)
changes in this commit:
1) sync command starts a fork immediately if no sync_delay is configured
2) replica sends REPLCONF ACK when done reading the rdb (rather than on 1s cron)
3) when a replica unexpectedly disconnets, it immediately tries to
re-connect rather than waiting 1s
4) when when a child exits, if there is another replica waiting, we spawn a new
one right away, instead of waiting for 1s replicationCron.
5) added a call to connectWithMaster from replicationSetMaster. which is called
from the REPLICAOF command but also in 3 places in cluster.c, in all of
these the connection attempt will now be immediate instead of delayed by 1
second.
side note:
we can add a call to rdbPipeReadHandler in replconfCommand when getting
a REPLCONF ACK from the replica to solve a race where the replica got
the entire rdb and EOF marker before we detected that the pipe was
closed.
in the test i did see this race happens in one about of some 300 runs,
but i concluded that this race is unlikely in real life (where the
replica is on another host and we're more likely to first detect the
pipe was closed.
the test runs 100 iterations in 3 seconds, so in some cases it'll take 4
seconds instead (waiting for another REPLCONF ACK).
Removing unneeded startBgsaveForReplication from updateSlavesWaitingForBgsave
Now that CheckChildrenDone is calling the new replicationStartPendingFork
(extracted from serverCron) there's actually no need to call
startBgsaveForReplication from updateSlavesWaitingForBgsave anymore,
since as soon as updateSlavesWaitingForBgsave returns, CheckChildrenDone is
calling replicationStartPendingFork that handles that anyway.
The code in updateSlavesWaitingForBgsave had a bug in which it ignored
repl-diskless-sync-delay, but removing that code shows that this bug was
hiding another bug, which is that the max_idle should have used >= and
not >, this one second delay has a big impact on my new test.
Syntax: `ZMSCORE KEY MEMBER [MEMBER ...]`
This is an extension of #2359
amended by Tyson Andre to work with the changed unstable API,
add more tests, and consistently return an array.
- It seemed as if it would be more likely to get reviewed
after updating the implementation.
Currently, multi commands or lua scripting to call zscore multiple times
would almost definitely be less efficient than a native ZMSCORE
for the following reasons:
- Need to fetch the set from the string every time instead of reusing the C
pointer.
- Using pipelining or multi-commands would result in more bytes sent by
the client for the repeated `ZMSCORE KEY` sections.
- Need to specially encode the data and decode it from the client
for lua-based solutions.
- The fastest solution I've seen for large sets(thousands or millions)
involves lua and a variadic ZADD, then a ZINTERSECT, then a ZRANGE 0 -1,
then UNLINK of a temporary set (or lua). This is still inefficient.
Co-authored-by: Tyson Andre <tysonandre775@hotmail.com>
