introduces a NOMKSTREAM option for xadd command, this would be useful for some
use cases when we do not want to create new stream by default:
XADD key [MAXLEN [~|=] <count>] [NOMKSTREAM] <ID or *> [field value] [field value]
This cleans up and simplifies the API by passing the command name as the
first argument. Previously the command name was specified explicitly,
but was still included in the argv.
* Introduce a new API's: RM_GetContextFlagsAll, and
RM_GetKeyspaceNotificationFlagsAll that will return the
full flags mask of each feature. The module writer can
check base on this value if the Flags he needs are
supported or not.
* For each flag, introduce a new value on redismodule.h,
this value represents the LAST value and should be there
as a reminder to update it when a new value is added,
also it will be used in the code to calculate the full
flags mask (assuming flags are incrementally increasing).
In addition, stated that the module writer should not use
the LAST flag directly and he should use the GetFlagAll API's.
* Introduce a new API: RM_IsSubEventSupported, that returns for a given
event and subevent, whether or not the subevent supported.
* Introduce a new macro RMAPI_FUNC_SUPPORTED(func) that returns whether
or not a function API is supported by comparing it to NULL.
* Introduce a new API: int RM_GetServerVersion();, that will return the
current Redis version in the format 0x00MMmmpp; e.g. 0x00060008;
* Changed unstable version from 999.999.999 to 255.255.255
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Yossi Gottlieb <yossigo@gmail.com>
The main motivation here is to provide a way for modules to create a
single, global context that can be used for logging.
Currently, it is possible to obtain a thread-safe context that is not
attached to any blocked client by using `RM_GetThreadSafeContext`.
However, the attached context is not linked to the module identity so
log messages produced are not tagged with the module name.
Ideally we'd fix this in `RM_GetThreadSafeContext` itself but as it
doesn't accept the current context as an argument there's no way to do
that in a backwards compatible manner.
This is essentially the same as calling COMMAND GETKEYS but provides a
more efficient interface that can be used in every context (i.e. not a
Redis command).
Adding [B]LMOVE <src> <dst> RIGHT|LEFT RIGHT|LEFT. deprecating [B]RPOPLPUSH.
Note that when receiving a BRPOPLPUSH we'll still propagate an RPOPLPUSH,
but on BLMOVE RIGHT LEFT we'll propagate an LMOVE
improvement to existing tests
- Replace "after 1000" with "wait_for_condition" when wait for
clients to block/unblock.
- Add a pre-existing element to target list on basic tests so
that we can check if the new element was added to the correct
side of the list.
- check command stats on the replica to make sure the right
command was replicated
Co-authored-by: Oran Agra <oran@redislabs.com>
I suppose that it was overlooked, since till recently none of the blocked commands were readonly.
other changes:
- add test for the above.
- add better support for additional (and deferring) clients for
cluster tests
- improve a test which left the client in MULTI state.
track and report memory used by clients argv.
this is very usaful in case clients started sending a command and didn't
complete it. in which case the first args of the command are already
trimmed from the query buffer.
in an effort to avoid cache misses and overheads while keeping track of
these, i avoid calling sdsZmallocSize and instead use the sdslen /
bulk-len which can at least give some insight into the problem.
This memory is now added to the total clients memory usage, as well as
the client list.
Add optional GET parameter to SET command in order to set a new value to
a key and retrieve the old key value. With this change we can deprecate
`GETSET` command and use only the SET command with the GET parameter.
PROBLEM:
[$rd1 read] reads invalidation messages one by one, so it's never going to see the second invalidation message produced after INCR b, whether or not it exists. Adding another read will block incase no invalidation message is produced.
FIX:
We switch the order of "INCR a" and "INCR b" - now "INCR b" comes first. We still only read the first invalidation message produces. If an invalidation message is wrongly produces for b - then it will be produced before that of a, since "INCR b" comes before "INCR a".
Co-authored-by: Nitai Caro <caronita@amazon.com>
Before this commit, we would have continued to add replies to the reply buffer even if client
output buffer limit is reached, so the used memory would keep increasing over the configured limit.
What's more, we shouldn’t write any reply to the client if it is set 'CLIENT_CLOSE_ASAP' flag
because that doesn't conform to its definition and we will close all clients flagged with
'CLIENT_CLOSE_ASAP' in ‘beforeSleep’.
Because of code execution order, before this, we may firstly write to part of the replies to
the socket before disconnecting it, but in fact, we may can’t send the full replies to clients
since OS socket buffer is limited. But this unexpected behavior makes some commands work well,
for instance ACL DELUSER, if the client deletes the current user, we need to send reply to client
and close the connection, but before, we close the client firstly and write the reply to reply
buffer. secondly, we shouldn't do this despite the fact it works well in most cases.
We add a flag 'CLIENT_CLOSE_AFTER_COMMAND' to mark clients, this flag means we will close the
client after executing commands and send all entire replies, so that we can write replies to
reply buffer during executing commands, send replies to clients, and close them later.
We also fix some implicit problems. If client output buffer limit is enforced in 'multi/exec',
all commands will be executed completely in redis and clients will not read any reply instead of
partial replies. Even more, if the client executes 'ACL deluser' the using user in 'multi/exec',
it will not read the replies after 'ACL deluser' just like before executing 'client kill' itself
in 'multi/exec'.
We added some tests for output buffer limit breach during multi-exec and using a pipeline of
many small commands rather than one with big response.
Co-authored-by: Oran Agra <oran@redislabs.com>
XREADGROUP auto-creates the consumer inside the consumer group the
first time it saw it.
When XREADGROUP is being used with NOACK option, the message will not
be added into the client's PEL and XGROUP SETID would be propagated.
When the replica gets the XGROUP SETID it will only update the last delivered
id of the group, but will not create the consumer.
So, in this commit XGROUP CREATECONSUMER is being added.
Command pattern: XGROUP CREATECONSUMER <key> <group> <consumer>.
When NOACK option is being used, createconsumer command would be
propagated as well.
In case of AOFREWRITE, consumer with an empty PEL would be saved with
XGROUP CREATECONSUMER whereas consumer with pending entries would be
saved with XCLAIM
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>
- the test now waits for specific set of log messages rather than wait for
timeout looking for just one message.
- we don't wanna sample the current length of the log after an action, due
to a race, we need to start the search from the line number of the last
message we where waiting for.
- when attempting to trigger a full sync, use multi-exec to avoid a race
where the replica manages to re-connect before we completed the set of
actions that should force a full sync.
- fix verify_log_message which was broken and unused
on ci.redis.io the test fails a lot, reporting that bgsave didn't end.
increaseing the timeout we wait for that bgsave to get aborted.
in addition to that, i also verify that it indeed got aborted by
checking that the save counter wasn't reset.
add another test to verify that a successful bgsave indeed resets the
change counter.
in cases where you have
test name {
start_server {
start_server {
assert
}
}
}
the exception will be thrown to the test proc, and the servers are
supposed to be killed on the way out. but it seems there was always a
bug of not cleaning the server stack, and recently (#7404) we started
relying on that stack in order to kill them, so with that bug sometimes
we would have tried to kill the same server twice, and leave one alive.
luckly, in most cases the pattern is:
start_server {
test name {
}
}
This re-implements the redis-cli --pipe test so it no longer depends on a close feature available only in TCL 8.6.
Basically what this test does is run redis-cli --pipe, generates a bunch of commands and pipes them through redis-cli, and inspects the result in both Redis and the redis-cli output.
To do that, we need to close stdin for redis-cli to indicate we're done so it can flush its buffers and exit. TCL has bi-directional channels can only offers a way to "one-way close" a channel with TCL 8.6. To work around that, we now generate the commands into a file and feed that file to redis-cli directly.
As we're writing to an actual file, the number of commands is now reduced.
Before this commit, the output of "./runtest-cluster --help" is incorrect.
After this commit, the format of the following 3 output is consistent:
./runtest --help
./runtest-cluster --help
./runtest-sentinel --help
interestingly the latency monitor test fails because valgrind is slow
enough so that the time inside PEXPIREAT command from the moment of
the first mstime() call to get the basetime until checkAlreadyExpired
calls mstime() again is more than 1ms, and that test was too sensitive.
using this opportunity to speed up the test (unrelated to the failure)
the fix is just the longer time passed to PEXPIRE.
in the majority of the cases (on this rarely used feature) we want to
stop and be able to connect to the shard with redis-cli.
since these are two different processes interracting with the tty we
need to stop both, and we'll have to hit enter twice, but it's not that
bad considering it is rarely used.
* Tests: fix and reintroduce redis-cli tests.
These tests have been broken and disabled for 10 years now!
* TLS: add remaining redis-cli support.
This adds support for the redis-cli --pipe, --rdb and --replica options
previously unsupported in --tls mode.
* Fix writeConn().
Similarly to EXPIREAT with TTL in the past, which implicitly deletes the
key and return success, RESTORE should not store key that are already
expired into the db.
When used together with REPLACE it should emit a DEL to keyspace
notification and replication stream.
On some platforms strtold("+inf") with valgrind returns a non-inf result
[err]: INCRBYFLOAT does not allow NaN or Infinity in tests/unit/type/incr.tcl
Expected 'ERR*would produce*' to equal or match '1189731495357231765085759.....'
tests were sensitive to additional log lines appearing in the log
causing the search to come empty handed.
instead of just looking for the n last log lines, capture the log lines
before performing the action, and then search from that offset.
* tests/valgrind: don't use debug restart
DEBUG REATART causes two issues:
1. it uses execve which replaces the original process and valgrind doesn't
have a chance to check for errors, so leaks go unreported.
2. valgrind report invalid calls to close() which we're unable to resolve.
So now the tests use restart_server mechanism in the tests, that terminates
the old server and starts a new one, new PID, but same stdout, stderr.
since the stderr can contain two or more valgrind report, it is not enough
to just check for the absence of leaks, we also need to check for some known
errors, we do both, and fail if we either find an error, or can't find a
report saying there are no leaks.
other changes:
- when killing a server that was already terminated we check for leaks too.
- adding DEBUG LEAK which was used to test it.
- adding --trace-children to valgrind, although no longer needed.
- since the stdout contains two or more runs, we need slightly different way
of checking if the new process is up (explicitly looking for the new PID)
- move the code that handles --wait-server to happen earlier (before
watching the startup message in the log), and serve the restarted server too.
* squashme - CR fixes
In order to support the use of multi-exec in pipeline, it is important that
MULTI and EXEC are never rejected and it is easy for the client to know if the
connection is still in multi state.
It was easy to make sure MULTI and DISCARD never fail (done by previous
commits) since these only change the client state and don't do any actual
change in the server, but EXEC is a different story.
Since in the past, it was possible for clients to handle some EXEC errors and
retry the EXEC, we now can't affort to return any error on EXEC other than
EXECABORT, which now carries with it the real reason for the abort too.
Other fixes in this commit:
- Some checks that where performed at the time of queuing need to be re-
validated when EXEC runs, for instance if the transaction contains writes
commands, it needs to be aborted. there was one check that was already done
in execCommand (-READONLY), but other checks where missing: -OOM, -MISCONF,
-NOREPLICAS, -MASTERDOWN
- When a command is rejected by processCommand it was rejected with addReply,
which was not recognized as an error in case the bad command came from the
master. this will enable to count or MONITOR these errors in the future.
- make it easier for tests to create additional (non deferred) clients.
- add tests for the fixes of this commit.
The scan key module API provides the scan callback with the current
field name and value (if it exists). Those arguments are RedisModuleString*
which means it supposes to point to robj which is encoded as a string.
Using createStringObjectFromLongLong function might return robj that
points to an integer and so break a module that tries for example to
use RedisModule_StringPtrLen on the given field/value.
The PR introduces a fix that uses the createObject function and sdsfromlonglong function.
Using those function promise that the field and value pass to the to the
scan callback will be Strings.
The PR also changes the Scan test module to use RedisModule_StringPtrLen
to catch the issue. without this, the issue is hidden because
RedisModule_ReplyWithString knows to handle integer encoding of the
given robj (RedisModuleString).
The PR also introduces a new test to verify the issue is solved.
these tests create several edge cases that are otherwise uncovered (at
least not consistently) by the test suite, so although they're no longer
testing what they were meant to test, it's still a good idea to keep
them in hope that they'll expose some issue in the future.
