For my mistake, in the last revert commit in #13231, I originally wanted
to revert the last one, but reverted the penultimate fix.
Now that we have fix another potential memory read issue in [`743f1dd`
(#13231)](743f1dde79),
now it just seems to avoid confusion, i will verify in the future
whether it will have any impact, if so we will add this PR to backport.
Failed CI: https://github.com/sundb/redis/actions/runs/8826731960
Introducted by #13013
After defragmenting the dictionary in the kvstore, if the dict is
reallocated, the value of its node in the kvstore rehashing list must be
updated.
## Background
1. Currently Lua memory control does not pass through Redis's zmalloc.c.
Redis maxmemory cannot limit memory problems caused by users abusing lua
since these lua VM memory is not part of used_memory.
2. Since jemalloc is much better (fragmentation and speed), and also we
know it and trust it. we are
going to use jemalloc instead of libc to allocate the Lua VM code and
count it used memory.
## Process:
In this PR, we will use jemalloc in lua.
1. Create an arena for all lua vm (script and function), which is
shared, in order to avoid blocking defragger.
2. Create a bound tcache for the lua VM, since the lua VM and the main
thread are by default in the same tcache, and if there is no isolated
tcache, lua may request memory from the tcache which has just been freed
by main thread, and vice versa
On the other hand, since lua vm might be release in bio thread, but
tcache is not thread-safe, we need to recreate
the tcache every time we recreate the lua vm.
3. Remove lua memory statistics from memory fragmentation statistics to
avoid the effects of lua memory fragmentation
## Other
Add the following new fields to `INFO DEBUG` (we may promote them to
INFO MEMORY some day)
1. allocator_allocated_lua: total number of bytes allocated of lua arena
2. allocator_active_lua: total number of bytes in active pages allocated
in lua arena
3. allocator_resident_lua: maximum number of bytes in physically
resident data pages mapped in lua arena
4. allocator_frag_bytes_lua: fragment bytes in lua arena
This is oranagra's idea, and i got some help from sundb.
This solves the third point in #13102.
---------
Co-authored-by: debing.sun <debing.sun@redis.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
When using Redis Cloud, sendReadOnly() exit with `Error: ERR unknown
command 'READONLY'`.
It is impacting `--memkeys`, `--bigkeys`, `--hotkeys`, and will impact
`--keystats`.
Added one line to ignore this error.
issue introduced in #12735 (not yet released).
when the main thread and the module thread are in the same thread,
sched_yield() can work well.
when they are both bind to different cpus, sched_yield() will look for
the thread with the highest priority, and if the module thread is always
the highest priority on a cpu, it will take a long time to let the main
thread to reacquire the GIL.
ref https://man7.org/linux/man-pages/man2/sched_yield.2.html
```
If the calling thread is the only thread in the highest priority
list at that time, it will continue to run after a call to
sched_yield().
```
# Overview
Users utilize the `FLUSHDB SYNC` and `FLUSHALL SYNC` commands for a variety of
reasons. The main issue with this command is that if the database becomes
substantial in size, the server will be unresponsive for an extended period.
Other than freezing application traffic, this may also lead some clients making
incorrect judgments about the server's availability. For instance, a watchdog may
erroneously decide to terminate the process, resulting in potential adverse
outcomes. While a `FLUSH* ASYNC` can address these issues, it might not be used
for two reasons: firstly, it's not the default, and secondly, in some cases, the
client issuing the flush wants to wait for its completion before repopulating the
database.
Between the option of triggering FLUSH* asynchronously in the background without
indication for completion versus running it synchronously in the foreground by
the main thread, there is another more appealing option. We can block the
client that requested the flush, execute the flush command in the background, and
once done, unblock the client and return notification for completion. This approach
ensures the server remains responsive to other clients, and the blocked client
receives the expected response only after the flush operation has been successfully
carried out.
# Implementation details
Instead of defining yet another flavor to the flush command, we can modify
`FLUSHALL SYNC` and `FLUSHDB SYNC` always run in this new mode.
## Extending BIO Threads capabilities
Today jobs that are carried out by BIO threads don't have the capability to
indicate completion to the main thread. We can add this infrastructure by having
an additional dummy job, coined as completion-job, that eventually will be written
by BIO threads to a response-queue. The main thread will take care to consume items
from the response-queue and call the provided callback function of each
completion-job.
## FLUSH* SYNC to run as blocking ASYNC
Command `FLUSH* SYNC` will be modified to create one or more async jobs to flush
DB(s) and afterward will push additional completion-job request. By sending the
completion job request only at the end, the main thread will be called back only
after all the preceding jobs completed their task in the background. During that
time, the client of the command is suspended and marked as `BLOCKED_LAZYFREE`
whereas any other client will be able to communicate with the server without any
issue.
It calls kvstoreIteratorNextDict() which eventually calls dictResumeRehashing()
And then, on return, it calls dictResetIterator(iter) which calls dictResumeRehashing().
We end up with pauserehash value decremented twice instead of once.
In ASAN CI, we find server may crash because of NULL ptr in `kvstoreIncrementallyRehash`.
the reason is that we use two phase unlink in `dbGenericDelete`. After `kvstoreDictTwoPhaseUnlinkFind`,
the dict may be in rehashing and only have one element in ht[0] of `db->keys`.
When we delete the last element in `db->keys` meanwhile `db->keys` is in rehashing, we may free the
dict in `kvstoreDictTwoPhaseUnlinkFree` without deleting the node in `kvs->rehashing`. Then we may
use this freed ptr in `kvstoreIncrementallyRehash` in the `serverCron` and cause the crash.
This is indeed a use-after-free problem.
The fix is to call rehashingCompleted in dictRelease and dictEmpty, so that every call for
rehashingStarted is always matched with a rehashingCompleted.
Adding a test in the unit test to catch it consistently
---------
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: debing.sun <debing.sun@redis.com>
In `beginResultEmission`, -1 means the result length is not known in
advance. But after #12185, if we pass -1 to `zrangeResultBeginStore`, it
will convert to SIZE_MAX in `zsetTypeCreate` and try to `dictExpand`.
Although `dictExpand` won't succeed because the size overflows, I think
we'd better to avoid this wrong conversion.
This bug can be triggered when the source of `zrangestore` doesn't exist
or we use `zrangestore` command with `byscore` or `bylex`.
The impact is that dst keys will be converted to use skiplist instead of
listpack.
Users who abuse lua error_reply will generate a new error object on each
error call, which can make server.errors get bigger and bigger. This
will
cause the server to block when calling INFO (we also return errorstats
by
default).
To prevent the damage it can cause, when a misuse is detected, we will
print a warning log and disable the errorstats to avoid adding more new
errors. It can be re-enabled via CONFIG RESETSTAT.
Because server.errors may be very large (it may be better now since we
have the limit), config resetstat may block for a while. So in
resetErrorTableStats, we will try to lazyfree server.errors.
See the related discussion at the end of #8217.
After #13072, there is an use-after-free error. In expireScanCallback, we
will delete the dict, and then in dictScan we will continue to use the dict,
like we will doing `dictResumeRehashing(d)` in the end, this casued an error.
In this PR, in freeDictIfNeeded, if the dict's pauserehash is set, don't
delete the dict yet, and then when scan returns try to delete it again.
At the same time, we noticed that there will be similar problems in iterator.
We may also delete elements during the iteration process, causing the dict
to be deleted, so the part related to iter in the PR has also been modified.
dictResetIterator was also missing from the previous kvstoreIteratorNextDict,
we currently have no scenario that elements will be deleted in kvstoreIterator
process, deal with it together to avoid future problems. Added some simple
tests to verify the changes.
In addition, the modification in #13072 omitted initTempDb and emptyDbAsync,
and they were also added. This PR also remove the slow flag from the expire
test (consumes 1.3s) so that problems can be found in CI in the future.
This change to the Makefile makes it possible to opt out of
`-fno-omit-frame-pointer` added in #12973 and `-flto` (#11350). Those
features were implemented by conditionally modifying the `REDIS_CFLAGS`
and `REDIS_LDFLAGS` variables. Historically, those variables provided a
way for users to pass options to the compiler and linker unchanged.
Instead of conditionally appending optimization flags to REDIS_CFLAGS
and REDIS_LDFLAGS, I want to append them to the OPTIMIZATION variable.
Later in the Makefile, we have `OPT=$(OPTIMIZATION)` (meaning
OPTIMIZATION is only a default for OPT, but OPT can be overridden by the
user), and later the flags are combined like this:
FINAL_CFLAGS=$(STD) $(WARN) $(OPT) $(DEBUG) $(CFLAGS) $(REDIS_CFLAGS)
FINAL_LDFLAGS=$(LDFLAGS) $(OPT) $(REDIS_LDFLAGS) $(DEBUG)
This makes it possible for the the user to override all optimization
flags with e.g. `make OPT=-O1` or just `make OPT=`.
For some reason `-O3` was also already added to REDIS_LDFLAGS by default
in #12339, so I added OPT to FINAL_LDFLAGS to avoid more complex logic
(such as introducing a separate LD_OPT variable).
Currently (following #11695, and #12822), keys kvstore and expires
kvstore both flag with ON_DEMAND, it means that a cluster node will
only allocate a dict when the slot is assigned to it and populated,
but on the other hand, when the slot is unassigned, the dict will
remain allocated.
We considered releasing the dict when the slot is unassigned, but it
causes complications on replicas. On the other hand, from benchmarks
we conducted, it looks like the performance impact of releasing the
dict when it becomes empty and re-allocate it when a key is added
again, isn't huge.
This PR add KVSTORE_FREE_EMPTY_DICTS to cluster mode keys / expires
kvstore.
The impact is about about 2% performance drop, for this hopefully
uncommon scenario.
---------
Co-authored-by: Oran Agra <oran@redislabs.com>
In some cases, users will abuse lua eval. Each EVAL call generates
a new lua script, which is added to the lua interpreter and cached
to redis-server, consuming a large amount of memory over time.
Since EVAL is mostly the one that abuses the lua cache, and these
won't have pipeline issues (i.e. the script won't disappear
unexpectedly,
and cause errors like it would with SCRIPT LOAD and EVALSHA),
we implement a plain FIFO LRU eviction only for these (not for
scripts loaded with SCRIPT LOAD).
### Implementation notes:
When not abused we'll probably have less than 100 scripts, and when
abused we'll have many thousands. So we use a hard coded value of 500
scripts. And considering that we don't have many scripts, then unlike
keys, we don't need to worry about the memory usage of keeping a true
sorted LRU linked list. We compute the SHA of each script anyway,
and put the script in a dict, we can store a listNode there, and use
it for quick removal and re-insertion into an LRU list each time the
script is used.
### New interfaces:
At the same time, a new `evicted_scripts` field is added to
INFO, which represents the number of evicted eval scripts. Users
can check it to see if they are abusing EVAL.
### benchmark:
`./src/redis-benchmark -P 10 -n 1000000 -r 10000000000 eval "return
__rand_int__" 0`
The simple abuse of eval benchmark test that will create 1 million EVAL
scripts. The performance has been improved by 50%, and the max latency
has dropped from 500ms to 13ms (this may be caused by table expansion
inside Lua when the number of scripts is large). And in the INFO memory,
it used to consume 120MB (server cache) + 310MB (lua engine), but now
it only consumes 70KB (server cache) + 210KB (lua_engine) because of
the scripts eviction.
For non-abusive case of about 100 EVAL scripts, there's no noticeable
change in performance or memory usage.
### unlikely potentially breaking change:
in theory, a user can maybe load a
script with EVAL and then use EVALSHA to call it (by calculating the
SHA1 value on the client side), it could be that if we read the docs
carefully we'll realized it's a valid scenario, but we suppose it's
extremely rare. So it may happen that EVALSHA acts on a script created
by EVAL, and the script is evicted and EVALSHA returns a NOSCRIPT error.
that is if you have more than 500 scripts being used in the same
transaction / pipeline.
This solves the second point in #13102.
Allow using `+` as a special ID for last item in stream on XREAD
command.
This would allow to iterate on a stream with XREAD starting with the
last available message instead of the next one which `$` is used for.
I.e. the caller can use `BLOCK` and `+` on the first call, and change to
`$` on the next call.
Closes#7388
---------
Co-authored-by: Felipe Machado <462154+felipou@users.noreply.github.com>
Sometimes it's useful to compute a key's cluster slot in a module.
This API function is just like the command CLUSTER KEYSLOT (but faster).
A "reverse" API is also added:
`RedisModule_ClusterCanonicalKeyNameInSlot`. Given a slot, it returns a
short string that we can call a canonical key for the slot.
The check in fileIsManifest misjudged the manifest file. For example,
if resp aof contains "file", it will be considered a manifest file and
the check will fail:
```
*3
$3
set
$4
file
$4
file
```
In #12951, if the preamble aof also contains it, it will also fail.
Fixes#12951.
the bug was happening if the the word "file" is mentioned
in the first 1024 lines of the AOF. and now as soon as it finds
a non-comment line it'll break (if it contains "file" or doesn't)
Distribute operations via `redis-benchmark` on different slots owned by
node.
`current_slot_index` is never updated hence the value is always `0` and
the tag used is always the first slot owned by the node. Hence any
read/write operation via `redis-benchmark` in cluster mode always
happens on a particular slot.
This is inconvenient to load data uniformly via `redis-benchmark`.
Since lua_Number is not explicitly an integer or a double, we need to
make an effort
to convert it as an integer when that's possible, since the string could
later be used
in a context that doesn't support scientific notation (e.g. 1e9 instead
of 100000000).
Since fpconv_dtoa converts numbers with the equivalent of `%f` or `%e`,
which ever is shorter,
this would break if we try to pass a long integer number to a command
that takes integer.
we'll get an implicit conversion to string in Lua, and then the parsing
in getLongLongFromObjectOrReply will fail.
```
> eval "redis.call('hincrby', 'key', 'field', '1000000000')" 0
(nil)
> eval "redis.call('hincrby', 'key', 'field', tonumber('1000000000'))" 0
(error) ERR value is not an integer or out of range script: ac99c32e4daf7e300d593085b611de261954a946, on @user_script:1.
```
Switch to using ll2string if the number can be safely represented as a
long long.
The problem was introduced in #10587 (Redis 7.2).
closes#13113.
---------
Co-authored-by: Binbin <binloveplay1314@qq.com>
Co-authored-by: debing.sun <debing.sun@redis.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
Update the crc16 hash lookup table to use fixed size character arrays instead of pointers
to static string addresses. Since the actual values are so short, we can just store them
in a uniform array instead. This saves about 128kb of memory and should improve the
performance as well since we should have much better memory locality.
`CONFIG SET oom-score-adj handles configuration failures` test failed in
some CI jobs today.
Failed CI: https://github.com/redis/redis/actions/runs/8152519326
Not sure why the github action's docker image perssions have changed,
but the issue is similar to #12887,
where we can't assume the range of oom_score_adj that a user can change.
## Solution:
Modify the way of determining whether the current user has no privileges
or not,
instead of relying on whether the user id is 0 or not.
This commit updates the processing of PONG gossip messages in the
cluster. When a node (B) becomes a replica due to a failover, its PONG
messages include its new primary node's (A) information and B's
configuration epoch is aligned with A's. This allows observer nodes to
identify changes in primary-ship, addressing issues of intermediate
states and enhancing cluster state consistency during topology changes.
Fix#13018
After #13013
### This PR make effort to defrag the pubsub kvstore in the following
ways:
1. Till now server.pubsub(shard)_channels only share channel name obj
with the first subscribed client, now change it so that the clients and
the pubsub kvstore share the channel name robj.
This would save a lot of memory when there are many subscribers to the
same channel.
It also means that we only need to defrag the channel name robj in the
pubsub kvstore, and then update
all client references for the current channel, avoiding the need to
iterate through all the clients to do the same things.
2. Refactor the code to defragment pubsub(shard) in the same way as
defragment of keys and EXPIRES, with the exception that we only
defragment pubsub(without shard) when slot is zero.
### Other
Fix an overlook in #11695, if defragment doesn't reach the end time, we
should wait for the current
db's keys and expires, pubsub and pubsubshard to finish before leaving,
now it's possible to exit
early when the keys are defragmented.
---------
Co-authored-by: oranagra <oran@redislabs.com>
The new regular expression break the validator:
```
In file included from commands.c:10:
commands_with_reply_schema.def:14528:72: error: stray ‘\’ in program
14528 | struct jsonObjectElement MEMORY_STATS_ReplySchema_patternProperties__db\_\d+__properties_overhead_hashtable_main_elements[] = {
```
The reason is that special characters are not added to to_c_name,
causes special characters to appear in the structure name, causing
c file compilation to fail.
Broken by #12913
- In removeUnsupportedArgs, trying to access the next item after the
last one and causing an out of bounds read.
- In versionIsSupported, when the 'version' is equal to 'since', the
return value is 0 (not supported).
Also, change the function to return `not supported` in case they have
different numbers of digits
Both issues were found by `Non-interactive non-TTY CLI: Test
command-line hinting - old server` under `test-sanitizer-address` (When
changing the `src/version.h` locally to `8.0.0`)
The new `MAXAGE` argument inside `client-kill` triggered the issue (new
argument at the end of the list)
---------
Co-authored-by: YaacovHazan <yaacov.hazan@redislabs.com>
Sometimes we need to make fast judgement about why Redis is suddenly
taking more memory. One of the reasons is main DB's dicts doing
rehashing.
We may use `MEMORY STATS` to monitor the overhead memory of each DB, but
there still lacks a total sum to show an overall trend. So this PR adds
the total overhead of all DBs to `INFO MEMORY` section, together with
the total count of rehashing DB dicts, providing some intuitive metrics
about main dicts rehashing.
This PR adds the following metrics to INFO MEMORY
* `mem_overhead_db_hashtable_rehashing` - only size of ht[0] in
dictionaries we're rehashing (i.e. the memory that's gonna get released
soon)
and a similar ones to MEMORY STATS:
* `overhead.db.hashtable.lut` (complements the existing
`overhead.hashtable.main` and `overhead.hashtable.expires` which also
counts the `dictEntry` structs too)
* `overhead.db.hashtable.rehashing` - temporary rehashing overhead.
* `db.dict.rehashing.count` - number of top level dictionaries being
rehashed.
---------
Co-authored-by: zhaozhao.zz <zhaozhao.zz@alibaba-inc.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
In XREADGROUP ACK, because streamPropagateXCLAIM does not propagate
entries-read, entries-read will be inconsistent between master and
replicas.
I.e. if no entries were claimed, it would have propagated correctly, but
if some
were claimed, then the entries-read field would be inconsistent on the
replica.
The fix was suggested by guybe7, call streamPropagateGroupID
unconditionally,
so that we will normalize entries_read on the replicas. In the past, we
would
only set propagate_last_id when NOACK was specified. And in #9127,
XCLAIM did
not propagate entries_read in ACK, which would cause entries_read to be
inconsistent between master and replicas.
Another approach is add another arg to XCLAIM and let it propagate
entries_read,
but we decided not to use it. Because we want minimal damage in case
there's an
old target and new source (in the worst case scenario, the new source
doesn't
recognize XGROUP SETID ... ENTRIES READ and the lag is lost. If we
change XCLAIM,
the damage is much more severe).
In this patch, now if the user uses XREADGROUP .. COUNT 1 there will be
an additional
overhead of MULTI, EXEC and XGROUPSETID. We assume the extra command in
case of
COUNT 1 (4x factor, changing from one XCLAIM to
MULTI+XCLAIM+XSETID+EXEC), is probably
ok since reading just one entry is in any case very inefficient (a
client round trip
per record), so we're hoping it's not a common case.
Issue was introduced in #9127.
Even if we have SCRIPT FLUSH ASYNC now, when there are a lot of
lua scripts, SCRIPT FLUSH ASYNC will still block the main thread.
This is because lua_close is executed in the main thread, and lua
heap needs to release a lot of memory.
In this PR, we take the current lua instance on lctx.lua and call
lua_close on it in a background thread, to close it in async way.
This is MeirShpilraien's idea.
The --count option for redis-cli has been released in redis 7.2.
https://github.com/redis/redis/pull/12042
But I have found in code, that some logic was missing for using this
'count' option.
```
static redisReply *sendScan(unsigned long long *it) {
redisReply *reply;
if (config.pattern)
reply = redisCommand(context, "SCAN %llu MATCH %b COUNT %d",
*it, config.pattern, sdslen(config.pattern), config.count);
else
reply = redisCommand(context,"SCAN %llu",*it);
```
The intention was being able to using scan count.
But in this case, the --count will be only applied when 'pattern' is
declared.
So, I had fix it simply, to be worked properly - even if --pattern
option is not being used.
I tested it simply with time() command several times, and I could see it
works as intended with this commit.
The examples of test results are below:
```
# unstable build
time(./redis-cli -a $AUTH -p $PORT -h $HOST --scan >/dev/null 2>/dev/null)
real 0m1.287s
user 0m0.011s
sys 0m0.022s
# count is not applied
time(./redis-cli -a $AUTH -p $PORT -h $HOST --scan --count 1000 >/dev/null 2>/dev/null)
real 0m1.117s
user 0m0.011s
sys 0m0.020s
# count is applied with --pattern
time(./redis-cli -a $AUTH -p $PORT -h $HOST --scan --count 1000 --pattern "hash:*" >/dev/null 2>/dev/null)
real 0m0.045s
user 0m0.002s
sys 0m0.002s
```
```
# fix-redis-cli-scan-count build
time(./redis-cli -a $AUTH -p $PORT -h $HOST --scan >/dev/null 2>/dev/null)
real 0m1.084s
user 0m0.008s
sys 0m0.024s
# count is applied even if --pattern is not declared
time(./redis-cli -a $AUTH -p $PORT -h $HOST --scan --count 1000 >/dev/null 2>/dev/null)
real 0m0.043s
user 0m0.000s
sys 0m0.004s
# of course this also applied
time(./redis-cli -a $AUTH -p $PORT -h $HOST --scan --count 1000 --pattern "hash:*" >/dev/null 2>/dev/null)
real 0m0.031s
user 0m0.002s
sys 0m0.002s
```
Thanks a lot.
If we call `DEL` on expired keys, keys may be deleted in
`expireIfNeeded` and we don't need to call `dbSyncDelete` or
`dbAsyncDelete` after, which repeat the deletion process(i.e. find keys
in main db).
In this PR, I refine the return values of `expireIfNeeded` to indicate
whether we have deleted the expired key to avoid the potential redundant
deletion logic in `delGenericCommand`. Besides, because both KEY_EXPIRED
and KEY_DELETED are non-zero, this PR won't affect other functions
calling `expireIfNeeded`.
I also make a performance test. I first close active expiration by
`debug set-active-expire 0` and write 1 million keys with 1ms TTL. Then
I repeatedly delete 100 expired keys in one `DEL`. The results are as
follow, which shows that this PR can improve performance by about 10% in
this situation.
**unstable**
```
Summary:
throughput summary: 10080.65 requests per second
latency summary (msec):
avg min p50 p95 p99 max
0.953 0.136 0.959 1.215 1.335 2.247
```
**This PR**
```
Summary:
throughput summary: 11074.20 requests per second
latency summary (msec):
avg min p50 p95 p99 max
0.865 0.128 0.879 1.055 1.175 2.159
```
---------
Co-authored-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
Co-authored-by: Oran Agra <oran@redislabs.com>
In #8554, we added a MALLOC_MIN_SIZE to use a minimum allocation
size when using malloc(0). However, we did not update the size,
when malloc_size is missing.
When malloc_size exists, we record the size that was allocated
instead of the size that was requested. This would work with both
jemalloc, and libc malloc (the change in #8554, doesn't break this).
When malloc_size is missing, we allocate extra size_t bytes and
store the requested size in it. In that case, the requested size
is probably different than the allocated size anyway (the change
in #8554 doesn't conceptually change that).
So we have room for improvement since in this case we are aware
of the extra bytes we asked for. Same as we're also aware of the
extra size_t bytes we asked for.
In addition, some cleaning was done:
1. fixes some outupdated comments.
2. test cleanups
Implement #12699
This PR exposing Lua os.clock() api for getting the elapsed time of Lua
code execution.
Using:
```lua
local start = os.clock()
...
do something
...
local elpased = os.clock() - start
```
---------
Co-authored-by: Meir Shpilraien (Spielrein) <meir@redis.com>
Co-authored-by: Madelyn Olson <34459052+madolson@users.noreply.github.com>
Following #12568
In issue #9357, when inserting an element larger than 1GB, we currently
store it in a plain node instead of a listpack.
Presently, when we insert an element that exceeds the maximum size of a
packed node, it cannot be accommodated in any other nodes, thus ending
up isolated like a large element.
I.e. it's a node with only one element, but it's listpack encoded rather
than a plain buffer.
This PR lowers the threshold for considering an element as 'large' from
1GB to the maximum size of a node.
While this change doesn't completely resolve the bug mentioned in the
previous PR, it does mitigate its potential impact.
As a result of this change, we can now only use LSET to replace an
element with another element that falls below the maximum size
threshold.
In the worst-case scenario, with a fill of -5, the largest packed node
we can create is 2GB (32k * 64k):
* 32k: The smallest element in a listpack is 2 bytes, which allows us to
store up to 32k elements.
* 64k: This is the maximum size for a single quicklist node.
## Others
To fully fix#9357, we need more work, as discussed in #12568, when we
insert an element into a quicklistNode, it may be created in a new node,
put into another node, or merged, and we can't correctly delete the node
that was supposed to be deleted.
I'm not sure it's worth it, since it involves a lot of modifications.
Implement #12963
## Changes
1. large bins don't have external fragmentation or are at least
non-defraggable, so we should ignore the effect of
large bins when measuring fragmentation, and only measure fragmentation
of small bins. this affects both the allocator_frag* metrics and also
the active-defrag trigger
2. Adding INFO metrics for `muzzy` memory, which is memory returned to
the OS but still shows as RSS until the OS reclaims it.
---------
Co-authored-by: Oran Agra <oran@redislabs.com>
Recently I saw in CI that reply-schemas-validator fails here:
```
Failed validating 'minimum' in schema[1]['properties']['groups']['items']['properties']['consumers']['items']['properties']['active-time']:
{'description': 'Last time this consumer was active (successful '
'reading/claiming).',
'minimum': 0,
'type': 'integer'}
On instance['groups'][0]['consumers'][0]['active-time']:
-1729380548878722639
```
The reason is that in fuzzer, we may restore corrupted active-time,
which will cause the reply schema CI to fail.
The fuzzer can cause corrupt the state in many places, which will
bugs that mess up the reply, so we decided to skip logreqres.
Also, seen-time is the same type as active-time, adding the minimum.
---------
Co-authored-by: Oran Agra <oran@redislabs.com>
There is a timing issue in the test, close may arrive late, or in
freeClientAsync we will free the client in async way, which will
lead to errors in watching_clients statistics, since we will only
unwatch all keys when we truly freeClient.
Add a wait here to avoid this problem. Also fixed some outdated
comments i saw. The test was introduced in #12966.
We can see that the past time here happens to be busy_time_limit,
causing the test to fail:
```
[err]: RM_Call from blocked client in tests/unit/moduleapi/blockedclient.tcl
Expected '50' to be more than '50' (context: type eval line 26 cmd {assert_morethan [expr [clock clicks -milliseconds]-$start] $busy_time_limit} proc ::test)
```
It is reasonable for them to be equal, so equal is added here.
It should be noted that in the previous `Busy module command` test,
we also used assert_morethan_equal, so this should have been missed
at the time.
Currently redis uses O3 level optimization would remove the frame pointer
in the target bin.
In the very old past, when gcc optimized at O1 and above levels, the
frame pointer is deleted by default to improve performance. This saves
the RBP registers and reduces the pop/push instructions. But it makes it
difficult for us to observe the running status of the program. For
example, the perf tool cannot be used effectively, especially the modern
eBPF tools such as bcc/memleak.
Add readme about the command json folder, what it does, and who should
(not) use it.
see discussion
https://github.com/redis/redis/issues/9359#issuecomment-1936420698
---------
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Binbin <binloveplay1314@qq.com>
debing.sun