In certain scenario start_server may think it failed to start a redis server
although it started successfully. in these cases, it'll not terminate it, and
it'll remain running when the test is over.
In start_server if config doesn't have bind (the minimal.conf in introspection.tcl),
it will try to bind ipv4 and ipv6. One may success while other fails. It will
output "Could not create server TCP listening socket".
wait_server_started uses this message to check whether instance started
successfully. So it will consider that it failed even though redis started successfully.
Additionally, in some cases it wasn't clear to users why the server exited,
since the warning message printed to the log, could in some cases be harmless,
and in some cases fatal.
This PR adds makes a clear distinction between a warning log message and
a fatal one, and changes the test suite to look for the fatal message.
lookupKeyReadOrReply and lookupKeyWriteOrReply might decide to reply to the user
with the given robj reply. This reply might be an error reply and if so addReply
function is used instead of addReplyErrorObject which will cause the error reply not
to be counted on stats. The fix checks the first char in the reply and if its '-' (error)
it uses addReplyErrorObject.
REDISMODULE_CTX_FLAGS_EVICT and REDISMODULE_CTX_FLAGS_MAXMEMORY
shouldn't be set when the module is run inside a replica that doesn't do eviction.
one may argue that the database is under eviction (the master does eviction and sends DELs to the replica).
but on the other hand, we don't really know the master's configuration.
all that matters is if the current instance does evictions or not.
listenToPort attempts to gracefully handle and ignore certain errors but does not store errno prior to logging, which in turn calls several libc functions that may overwrite errno.
This has been discovered due to libmusl strftime() always returning with errno set to EINVAL, which resulted with docker-library/redis#273.
1. moduleReplicateMultiIfNeeded should use server.in_eval like
moduleHandlePropagationAfterCommandCallback
2. server.in_eval could have been set to 1 and not reset back
to 0 (a lot of missed early-exits after in_eval is already 1)
Note: The new assertions in processCommand cover (2) and I added
two module tests to cover (1)
Implications:
If an EVAL that failed (and thus left server.in_eval=1) runs before a module
command that replicates, the replication stream will contain MULTI (because
moduleReplicateMultiIfNeeded used to check server.lua_caller which is NULL
at this point) but not EXEC (because server.in_eval==1)
This only affects modules as module.c the only user of server.in_eval.
Affects versions 6.2.0, 6.2.1
On a replica we do accept connections, even though commands accessing
the database will operate in read-only mode. But the server is still
already operational and processing commands.
Not sending the readiness notification means that on a HA setup where
the nodes all start as replicas (with replicaof in the config) with
a replica that cannot connect to the master server and which might not
come back in a predictable amount of time or at all, the service
supervisor will end up timing out the service and terminating it, with
no option to promote it to be the main instance. This seems counter to
what the readiness notification is supposed to be signaling.
Instead send the readiness notification when we start accepting
commands, and then send the various server status changes as that.
Fixes: commit 641c64ada10404356fc76c0b56a69b32c76f253c
Fixes: commit dfb598cf3304818e608ceb6b5d9529a293345c4a
Bug 1:
When a module ctx is freed moduleHandlePropagationAfterCommandCallback
is called and handles propagation. We want to prevent it from propagating
commands that were not replicated by the same context. Example:
1. module1.foo does: RM_Replicate(cmd1); RM_Call(cmd2); RM_Replicate(cmd3)
2. RM_Replicate(cmd1) propagates MULTI and adds cmd1 to also_propagagte
3. RM_Call(cmd2) create a new ctx, calls call() and destroys the ctx.
4. moduleHandlePropagationAfterCommandCallback is called, calling
alsoPropagates EXEC (Note: EXEC is still not written to socket),
setting server.in_trnsaction = 0
5. RM_Replicate(cmd3) is called, propagagting yet another MULTI (now
we have nested MULTI calls, which is no good) and then cmd3
We must prevent RM_Call(cmd2) from resetting server.in_transaction.
REDISMODULE_CTX_MULTI_EMITTED was revived for that purpose.
Bug 2:
Fix issues with nested RM_Call where some have '!' and some don't.
Example:
1. module1.foo does RM_Call of module2.bar without replication (i.e. no '!')
2. module2.bar internally calls RM_Call of INCR with '!'
3. at the end of module1.foo we call RM_ReplicateVerbatim
We want the replica/AOF to see only module1.foo and not the INCR from module2.bar
Introduced a global replication_allowed flag inside RM_Call to determine
whether we need to replicate or not (even if '!' was specified)
Other changes:
Split beforePropagateMultiOrExec to beforePropagateMulti afterPropagateExec
just for better readability
Have a clear separation between in and out flags
Other changes:
delete dead code in RM_ZsetIncrby: if zsetAdd returned error (happens only if
the result of the operation is NAN or if score is NAN) we return immediately so
there is no way that zsetAdd succeeded and returned NAN in the out-flags
`master_sync_perc` and `loading_loaded_perc` don't have that sign,
and i think the info field should be a raw floating point number (the name suggests its units).
we already have `used_memory_peak_perc` and `used_memory_dataset_perc` which do add the `%` sign, but:
1) i think it was a mistake but maybe too late to fix now, and maybe not too late to fix for `current_fork_perc`
2) it is more important to be consistent with the two other "progress" "prec" metrics, and not with the "utilization" metric.
1. Add `redis-server test all` support to run all tests.
2. Add redis test to daily ci.
3. Add `--accurate` option to run slow tests for more iterations (so that
by default we run less cycles (shorter time, and less prints).
4. Move dict benchmark to REDIS_TEST.
5. fix some leaks in tests
6. make quicklist tests run on a specific fill set of options rather than huge ranges
7. move some prints in quicklist test outside their loops to reduce prints
8. removing sds.h from dict.c since it is now used in both redis-server and
redis-cli (uses hiredis sds)
The obtained process_rss was incorrect (the OS reports pages, not
bytes), resulting with many other fields getting corrupted.
This has been tested on FreeBSD but not other platforms.
When a quicklist has quicklist->compress * 2 nodes, then call
__quicklistCompress, all nodes will be decompressed and the middle
two nodes will be recompressed again. This violates the fact that
quicklist->compress * 2 nodes are uncompressed. It's harmless
because when visit a node, we always try to uncompress node first.
This only happened when a quicklist has quicklist->compress * 2 + 1
nodes, then delete a node. For other scenarios like insert node and
iterate this will not happen.
It seems like non-Linux sockets may be less greedy, resulting with more
transient client output buffers.
Haven't proven this but empirically when stressing this test on
non-Linux tends to exhibit increased mem_clients_normal values.
Scenario:
1. A module client is blocked on keys with a timeout
2. Shortly before the timeout expires, the key is being populated and signaled
as ready
3. Redis calls moduleTryServeClientBlockedOnKey (which replies to client) and
then moduleUnblockClient
4. moduleUnblockClient doesn't really unblock the client, it writes to
server.module_blocked_pipe and only marks the BC as unblocked.
5. beforeSleep kics in, by this time the client still exists and techincally
timed-out. beforeSleep replies to the timeout client (double reply) and
only then moduleHandleBlockedClients is called, reading from module_blocked_pipe
and calling unblockClient
The solution is similar to what was done in moduleTryServeClientBlockedOnKey: we
should avoid re-processing an already-unblocked client
