Scenario:
1. client block on command `XREAD BLOCK 0 STREAMS mystream $`
2. in a module, calling `XADD mystream * field value` via lua from a timer callback
3. client will receive response after some latency up to 100ms
Reason:
When `XADD` signal the key `mystream` as ready, `beforeSleep` in next eventloop will call
`handleClientsBlockedOnKeys` to unblock the client and add pending data to write but not
actually install a write handler, so next redis will block in `aeApiPoll` up to 100ms given `hz`
config as default 10, pending data will be sent in another next eventloop by
`handleClientsWithPendingWritesUsingThreads`.
Calling `handleClientsBlockedOnKeys` before `handleClientsWithPendingWritesUsingThreads`
in `beforeSleep` solves the problem.
This change sets a low limit for multibulk and bulk length in the
protocol for unauthenticated connections, so that they can't easily
cause redis to allocate massive amounts of memory by sending just a few
characters on the network.
The new limits are 10 arguments of 16kb each (instead of 1m of 512mb)
Fixing CI test issues introduced in #8687
- valgrind warnings in readQueryFromClient when client was freed by processInputBuffer
- adding DEBUG pause-cron for tests not to be time dependent.
- skipping a test that depends on socket buffers / events not compatible with TLS
- making sure client got subscribed by not using deferring client
### Description
A mechanism for disconnecting clients when the sum of all connected clients is above a
configured limit. This prevents eviction or OOM caused by accumulated used memory
between all clients. It's a complimentary mechanism to the `client-output-buffer-limit`
mechanism which takes into account not only a single client and not only output buffers
but rather all memory used by all clients.
#### Design
The general design is as following:
* We track memory usage of each client, taking into account all memory used by the
client (query buffer, output buffer, parsed arguments, etc...). This is kept up to date
after reading from the socket, after processing commands and after writing to the socket.
* Based on the used memory we sort all clients into buckets. Each bucket contains all
clients using up up to x2 memory of the clients in the bucket below it. For example up
to 1m clients, up to 2m clients, up to 4m clients, ...
* Before processing a command and before sleep we check if we're over the configured
limit. If we are we start disconnecting clients from larger buckets downwards until we're
under the limit.
#### Config
`maxmemory-clients` max memory all clients are allowed to consume, above this threshold
we disconnect clients.
This config can either be set to 0 (meaning no limit), a size in bytes (possibly with MB/GB
suffix), or as a percentage of `maxmemory` by using the `%` suffix (e.g. setting it to `10%`
would mean 10% of `maxmemory`).
#### Important code changes
* During the development I encountered yet more situations where our io-threads access
global vars. And needed to fix them. I also had to handle keeps the clients sorted into the
memory buckets (which are global) while their memory usage changes in the io-thread.
To achieve this I decided to simplify how we check if we're in an io-thread and make it
much more explicit. I removed the `CLIENT_PENDING_READ` flag used for checking
if the client is in an io-thread (it wasn't used for anything else) and just used the global
`io_threads_op` variable the same way to check during writes.
* I optimized the cleanup of the client from the `clients_pending_read` list on client freeing.
We now store a pointer in the `client` struct to this list so we don't need to search in it
(`pending_read_list_node`).
* Added `evicted_clients` stat to `INFO` command.
* Added `CLIENT NO-EVICT ON|OFF` sub command to exclude a specific client from the
client eviction mechanism. Added corrosponding 'e' flag in the client info string.
* Added `multi-mem` field in the client info string to show how much memory is used up
by buffered multi commands.
* Client `tot-mem` now accounts for buffered multi-commands, pubsub patterns and
channels (partially), tracking prefixes (partially).
* CLIENT_CLOSE_ASAP flag is now handled in a new `beforeNextClient()` function so
clients will be disconnected between processing different clients and not only before sleep.
This new function can be used in the future for work we want to do outside the command
processing loop but don't want to wait for all clients to be processed before we get to it.
Specifically I wanted to handle output-buffer-limit related closing before we process client
eviction in case the two race with each other.
* Added a `DEBUG CLIENT-EVICTION` command to print out info about the client eviction
buckets.
* Each client now holds a pointer to the client eviction memory usage bucket it belongs to
and listNode to itself in that bucket for quick removal.
* Global `io_threads_op` variable now can contain a `IO_THREADS_OP_IDLE` value
indicating no io-threading is currently being executed.
* In order to track memory used by each clients in real-time we can't rely on updating
these stats in `clientsCron()` alone anymore. So now I call `updateClientMemUsage()`
(used to be `clientsCronTrackClientsMemUsage()`) after command processing, after
writing data to pubsub clients, after writing the output buffer and after reading from the
socket (and maybe other places too). The function is written to be fast.
* Clients are evicted if needed (with appropriate log line) in `beforeSleep()` and before
processing a command (before performing oom-checks and key-eviction).
* All clients memory usage buckets are grouped as follows:
* All clients using less than 64k.
* 64K..128K
* 128K..256K
* ...
* 2G..4G
* All clients using 4g and up.
* Added client-eviction.tcl with a bunch of tests for the new mechanism.
* Extended maxmemory.tcl to test the interaction between maxmemory and
maxmemory-clients settings.
* Added an option to flag a numeric configuration variable as a "percent", this means that
if we encounter a '%' after the number in the config file (or config set command) we
consider it as valid. Such a number is store internally as a negative value. This way an
integer value can be interpreted as either a percent (negative) or absolute value (positive).
This is useful for example if some numeric configuration can optionally be set to a percentage
of something else.
Co-authored-by: Oran Agra <oran@redislabs.com>
This commit introduced a new flag to the RM_Call:
'C' - Check if the command can be executed according to the ACLs associated with it.
Also, three new API's added to check if a command, key, or channel can be executed or accessed
by a user, according to the ACLs associated with it.
- RM_ACLCheckCommandPerm
- RM_ACLCheckKeyPerm
- RM_ACLCheckChannelPerm
The user for these API's is a RedisModuleUser object, that for a Module user returned by the RM_CreateModuleUser API, or for a general ACL user can be retrieved by these two new API's:
- RM_GetCurrentUserName - Retrieve the user name of the client connection behind the current context.
- RM_GetModuleUserFromUserName - Get a RedisModuleUser from a user name
As a result of getting a RedisModuleUser from name, it can now also access the general ACL users (not just ones created by the module).
This mean the already existing API RM_SetModuleUserACL(), can be used to change the ACL rules for such users.
This is similar to the recent addition of LMPOP/BLMPOP (#9373), but zset.
Syntax for the new ZMPOP command:
`ZMPOP numkeys [<key> ...] MIN|MAX [COUNT count]`
Syntax for the new BZMPOP command:
`BZMPOP timeout numkeys [<key> ...] MIN|MAX [COUNT count]`
Some background:
- ZPOPMIN/ZPOPMAX take only one key, and can return multiple elements.
- BZPOPMIN/BZPOPMAX take multiple keys, but return only one element from just one key.
- ZMPOP/BZMPOP can take multiple keys, and can return multiple elements from just one key.
Note that ZMPOP/BZMPOP can take multiple keys, it eventually operates on just on key.
And it will propagate as ZPOPMIN or ZPOPMAX with the COUNT option.
As new commands, if we can not pop any elements, the response like:
- ZMPOP: Return a NIL in both RESP2 and RESP3, unlike ZPOPMIN/ZPOPMAX return emptyarray.
- BZMPOP: Return a NIL in both RESP2 and RESP3 when timeout is reached, like BZPOPMIN/BZPOPMAX.
For the normal response is nested arrays in RESP2 and RESP3:
```
ZMPOP/BZMPOP
1) keyname
2) 1) 1) member1
2) score1
2) 1) member2
2) score2
In RESP2:
1) "myzset"
2) 1) 1) "three"
2) "3"
2) 1) "two"
2) "2"
In RESP3:
1) "myzset"
2) 1) 1) "three"
2) (double) 3
2) 1) "two"
2) (double) 2
```
Implements the [LIMIT limit] variant of SINTERCARD/ZINTERCARD.
Now with the LIMIT, we can stop the searching when cardinality
reaching the limit, and return the cardinality ASAP.
Note that in SINTERCARD, the old synatx was: `SINTERCARD key [key ...]`
In order to add a optional parameter, we must break the old synatx.
So the new syntax of SINTERCARD will be consistent with ZINTERCARD.
New syntax: `SINTERCARD numkeys key [key ...] [LIMIT limit]`.
Note that this means that SINTERCARD has a different syntax than
SINTER and SINTERSTORE (taking numkeys argument)
As for ZINTERCARD, we can easily add a optional parameter to it.
New syntax: `ZINTERCARD numkeys key [key ...] [LIMIT limit]`
The `cmd` argument was completely unused, and all the code that bothered to pass it was unnecessary.
This is a prepartion for a future commit that treats subcommands as commands
Fix#7297
The problem:
Today, there is no way for a client library or app to know the key name indexes for commands such as
ZUNIONSTORE/EVAL and others with "numkeys", since COMMAND INFO returns no useful info for them.
For cluster-aware redis clients, this requires to 'patch' the client library code specifically for each of these commands or to
resolve each execution of these commands with COMMAND GETKEYS.
The solution:
Introducing key specs other than the legacy "range" (first,last,step)
The 8th element of the command info array, if exists, holds an array of key specs. The array may be empty, which indicates
the command doesn't take any key arguments or may contain one or more key-specs, each one may leads to the discovery
of 0 or more key arguments.
A client library that doesn't support this key-spec feature will keep using the first,last,step and movablekeys flag which will
obviously remain unchanged.
A client that supports this key-specs feature needs only to look at the key-specs array. If it finds an unrecognized spec, it
must resort to using COMMAND GETKEYS if it wishes to get all key name arguments, but if all it needs is one key in order
to know which cluster node to use, then maybe another spec (if the command has several) can supply that, and there's no
need to use GETKEYS.
Each spec is an array of arguments, first one is the spec name, the second is an array of flags, and the third is an array
containing details about the spec (specific meaning for each spec type)
The initial flags we support are "read" and "write" indicating if the keys that this key-spec finds are used for read or for write.
clients should ignore any unfamiliar flags.
In order to easily find the positions of keys in a given array of args we introduce keys specs. There are two logical steps of
key specs:
1. `start_search`: Given an array of args, indicate where we should start searching for keys
2. `find_keys`: Given the output of start_search and an array of args, indicate all possible indices of keys.
### start_search step specs
- `index`: specify an argument index explicitly
- `index`: 0 based index (1 means the first command argument)
- `keyword`: specify a string to match in `argv`. We should start searching for keys just after the keyword appears.
- `keyword`: the string to search for
- `start_search`: an index from which to start the keyword search (can be negative, which means to search from the end)
Examples:
- `SET` has start_search of type `index` with value `1`
- `XREAD` has start_search of type `keyword` with value `[“STREAMS”,1]`
- `MIGRATE` has start_search of type `keyword` with value `[“KEYS”,-2]`
### find_keys step specs
- `range`: specify `[count, step, limit]`.
- `lastkey`: index of the last key. relative to the index returned from begin_search. -1 indicating till the last argument, -2 one before the last
- `step`: how many args should we skip after finding a key, in order to find the next one
- `limit`: if count is -1, we use limit to stop the search by a factor. 0 and 1 mean no limit. 2 means ½ of the remaining args, 3 means ⅓, and so on.
- “keynum”: specify `[keynum_index, first_key_index, step]`.
- `keynum_index`: is relative to the return of the `start_search` spec.
- `first_key_index`: is relative to `keynum_index`.
- `step`: how many args should we skip after finding a key, in order to find the next one
Examples:
- `SET` has `range` of `[0,1,0]`
- `MSET` has `range` of `[-1,2,0]`
- `XREAD` has `range` of `[-1,1,2]`
- `ZUNION` has `start_search` of type `index` with value `1` and `find_keys` of type `keynum` with value `[0,1,1]`
- `AI.DAGRUN` has `start_search` of type `keyword` with value `[“LOAD“,1]` and `find_keys` of type `keynum` with value
`[0,1,1]` (see https://oss.redislabs.com/redisai/master/commands/#aidagrun)
Note: this solution is not perfect as the module writers can come up with anything, but at least we will be able to find the key
args of the vast majority of commands.
If one of the above specs can’t describe the key positions, the module writer can always fall back to the `getkeys-api` option.
Some keys cannot be found easily (`KEYS` in `MIGRATE`: Imagine the argument for `AUTH` is the string “KEYS” - we will
start searching in the wrong index).
The guarantee is that the specs may be incomplete (`incomplete` will be specified in the spec to denote that) but we never
report false information (assuming the command syntax is correct).
For `MIGRATE` we start searching from the end - `startfrom=-1` - and if one of the keys is actually called "keys" we will
report only a subset of all keys - hence the `incomplete` flag.
Some `incomplete` specs can be completely empty (i.e. UNKNOWN begin_search) which should tell the client that
COMMAND GETKEYS (or any other way to get the keys) must be used (Example: For `SORT` there is no way to describe
the STORE keyword spec, as the word "store" can appear anywhere in the command).
We will expose these key specs in the `COMMAND` command so that clients can learn, on startup, where the keys are for
all commands instead of holding hardcoded tables or use `COMMAND GETKEYS` in runtime.
Comments:
1. Redis doesn't internally use the new specs, they are only used for COMMAND output.
2. In order to support the current COMMAND INFO format (reply array indices 4, 5, 6) we created a synthetic range, called
legacy_range, that, if possible, is built according to the new specs.
3. Redis currently uses only getkeys_proc or the legacy_range to get the keys indices (in COMMAND GETKEYS for
example).
"incomplete" specs:
the command we have issues with are MIGRATE, STRALGO, and SORT
for MIGRATE, because the token KEYS, if exists, must be the last token, we can search in reverse. it one of the keys is
actually the string "keys" will return just a subset of the keys (hence, it's "incomplete")
for SORT and STRALGO we can use this heuristic (the keys can be anywhere in the command) and therefore we added a
key spec that is both "incomplete" and of "unknown type"
if a client encounters an "incomplete" spec it means that it must find a different way (either COMMAND GETKEYS or have
its own parser) to retrieve the keys.
please note that all commands, apart from the three mentioned above, have "complete" key specs
The main idea is how to allow a master to load replication info from RDB file when rebooting, if master can load replication info it means that replicas may have the chance to psync with master, it can save much traffic.
The key point is we need guarantee safety and consistency, so there
are two differences between master and replica:
1. master would load the replication info as secondary ID and
offset, in case other masters have the same replid.
2. when master loading RDB, it would propagate expired keys as DEL
command to replication backlog, then replica can receive these
commands to delete stale keys.
p.s. the expired keys when RDB loading is useful for users, so
we show it as `rdb_last_load_keys_expired` and `rdb_last_load_keys_loaded` in info persistence.
Moreover, after load replication info, master should update
`no_replica_time` in case loading RDB cost too long time.
A write request may be paused unexpectedly because `server.client_pause_end_time` is old.
**Recreate this:**
redis-cli -p 6379
127.0.0.1:6379> client pause 500000000 write
OK
127.0.0.1:6379> client unpause
OK
127.0.0.1:6379> client pause 10000 write
OK
127.0.0.1:6379> set key value
The write request `set key value` is paused util the timeout of 500000000 milliseconds was reached.
**Fix:**
reset `server.client_pause_end_time` = 0 in `unpauseClients`
We want to add COUNT option for BLPOP.
But we can't do it without breaking compatibility due to the command arguments syntax.
So this commit introduce two new commands.
Syntax for the new LMPOP command:
`LMPOP numkeys [<key> ...] LEFT|RIGHT [COUNT count]`
Syntax for the new BLMPOP command:
`BLMPOP timeout numkeys [<key> ...] LEFT|RIGHT [COUNT count]`
Some background:
- LPOP takes one key, and can return multiple elements.
- BLPOP takes multiple keys, but returns one element from just one key.
- LMPOP can take multiple keys and return multiple elements from just one key.
Note that LMPOP/BLMPOP can take multiple keys, it eventually operates on just one key.
And it will propagate as LPOP or RPOP with the COUNT option.
As a new command, it still return NIL if we can't pop any elements.
For the normal response is nested arrays in RESP2 and RESP3, like:
```
LMPOP/BLMPOP
1) keyname
2) 1) element1
2) element2
```
I.e. unlike BLPOP that returns a key name and one element so it uses a flat array,
and LPOP that returns multiple elements with no key name, and again uses a flat array,
this one has to return a nested array, and it does for for both RESP2 and RESP3 (like SCAN does)
Some discuss can see: #766#8824
Add two INFO metrics:
```
total_active_defrag_time:12345
current_active_defrag_time:456
```
`current_active_defrag_time` if greater than 0, means how much time has
passed since active defrag started running. If active defrag stops, this metric is reset to 0.
`total_active_defrag_time` means total time the fragmentation
was over the defrag threshold since the server started.
This is a followup PR for #9031
When a replica paused, it would not apply any commands event the command comes from master, if we feed the non-applied command to replication stream, the replication offset would be wrong, and data would be lost after failover(since replica's `master_repl_offset` grows but command is not applied).
To fix it, here are the changes:
* Don't update replica's replication offset or propagate commands to sub-replicas when it's paused in `commandProcessed`.
* Show `slave_read_repl_offset` in info reply.
* Add an assert to make sure master client should never be blocked unless pause or module (some modules may use block way to do background (parallel) processing and forward original block module command to the replica, it's not a good way but it can work, so the assert excludes module now, but someday in future all modules should rewrite block command to propagate like what `BLPOP` does).
1. MIGRATE has a potnetial key arg in argv[3]. It should be reflected in the command table.
2. getKeysUsingCommandTable should never free getKeysResult, it is always freed by the caller)
The reason we never encountered this double-free bug is that almost always getKeysResult
uses the statis buffer and doesn't allocate a new one.
* Enhance dict to support arbitrary metadata carried in dictEntry
Co-authored-by: Viktor Söderqvist <viktor.soderqvist@est.tech>
* Rewrite slot-to-keys mapping to linked lists using dict entry metadata
This is a memory enhancement for Redis Cluster.
The radix tree slots_to_keys (which duplicates all key names prefixed with their
slot number) is replaced with a linked list for each slot. The dict entries of
the same cluster slot form a linked list and the pointers are stored as metadata
in each dict entry of the main DB dict.
This commit also moves the slot-to-key API from db.c to cluster.c.
Co-authored-by: Jim Brunner <brunnerj@amazon.com>
When `decr_step` is greater than `oldlimit`, the final `bestlimit` may be invalid.
For example, oldlimit = 10, decr_step = 16.
Current bestlimit = 15 and setrlimit() failed. Since bestlimit is less than decr_step , then exit the loop.
The final bestlimit is larger than oldlimit but is invalid.
Note that this only matters if the system fd limit is below 16, so unlikely to have any actual effect.
The order of setting things up follows some reasoning: Setup signal
handlers first because a signal could fire at any time. Adjust OOM score
before everything else to assist the OOM killer if memory resources are
low.
The trigger for this is a valgrind test failure which resulted with the
child catching a SIGUSR1 before initializing the handler.
Part one of implementing #8702 (taking hashes first before other types)
## Description of the feature
1. Change ziplist encoded hash objects to listpack encoding.
2. Convert existing ziplists on RDB loading time. an O(n) operation.
## Rdb format changes
1. Add RDB_TYPE_HASH_LISTPACK rdb type.
2. Bump RDB_VERSION to 10
## Interface changes
1. New `hash-max-listpack-entries` config is an alias for `hash-max-ziplist-entries` (same with `hash-max-listpack-value`)
2. OBJECT ENCODING will return `listpack` instead of `ziplist`
## Listpack improvements:
1. Support direct insert, replace integer element (rather than convert back and forth from string)
3. Add more listpack capabilities to match the ziplist ones (like `lpFind`, `lpRandomPairs` and such)
4. Optimize element length fetching, avoid multiple calculations
5. Use inline to avoid function call overhead.
## Tests
1. Add a new test to the RDB load time conversion
2. Adding the listpack unit tests. (based on the one in ziplist.c)
3. Add a few "corrupt payload: fuzzer findings" tests, and slightly modify existing ones.
Co-authored-by: Oran Agra <oran@redislabs.com>
Reduce dict struct memory overhead
on 64bit dict size goes down from jemalloc's 96 byte bin to its 56 byte bin.
summary of changes:
- Remove `privdata` from callbacks and dict creation. (this affects many files, see "Interface change" below).
- Meld `dictht` struct into the `dict` struct to eliminate struct padding. (this affects just dict.c and defrag.c)
- Eliminate the `sizemask` field, can be calculated from size when needed.
- Convert the `size` field into `size_exp` (exponent), utilizes one byte instead of 8.
Interface change: pass dict pointer to dict type call back functions.
This is instead of passing the removed privdata field. In the future if
we'd like to have private data in the callbacks we can extract it from
the dict type. We can extend dictType to include a custom dict struct
allocator and use it to allocate more data at the end of the dict
struct. This data can then be used to store private data later acccessed
by the callbacks.
## Backgroud
As we know, after `fork`, one process will copy pages when writing data to these
pages(CoW), and another process still keep old pages, they totally cost more memory.
For redis, we suffered that redis consumed much memory when the fork child is serializing
key/values, even that maybe cause OOM.
But actually we find, in redis fork child process, the child process don't need to keep some
memory and parent process may write or update that, for example, child process will never
access the key-value that is serialized but users may update it in parent process.
So we think it may reduce COW if the child process release memory that it is not needed.
## Implementation
For releasing key value in child process, we may think we call `decrRefCount` to free memory,
but i find the fork child process still use much memory when we don't write any data to redis,
and it costs much more time that slows down bgsave. Maybe because memory allocator doesn't
really release memory to OS, and it may modify some inner data for this free operation, especially
when we free small objects.
Moreover, CoW is based on pages, so it is a easy way that we only free the memory bulk that is
not less than kernel page size. madvise(MADV_DONTNEED) can quickly release specified region
pages to OS bypassing memory allocator, and allocator still consider that this memory still is used
and don't change its inner data.
There are some buffers we can release in the fork child process:
- **Serialized key-values**
the fork child process never access serialized key-values, so we try to free them.
Because we only can release big bulk memory, and it is time consumed to iterate all
items/members/fields/entries of complex data type. So we decide to iterate them and
try to release them only when their average size of item/member/field/entry is more
than page size of OS.
- **Replication backlog**
Because replication backlog is a cycle buffer, it will be changed quickly if redis has heavy
write traffic, but in fork child process, we don't need to access that.
- **Client buffers**
If clients have requests during having the fork child process, clients' buffer also be changed
frequently. The memory includes client query buffer, output buffer, and client struct used memory.
To get child process peak private dirty memory, we need to count peak memory instead
of last used memory, because the child process may continue to release memory (since
COW used to only grow till now, the last was equivalent to the peak).
Also we're adding a new `current_cow_peak` info variable (to complement the existing
`current_cow_size`)
Co-authored-by: Oran Agra <oran@redislabs.com>
Add SINTERCARD and ZINTERCARD commands that are similar to
ZINTER and SINTER but only return the cardinality with minimum
processing and memory overheads.
Co-authored-by: Oran Agra <oran@redislabs.com>
1. In sendBulkToSlave, we used LL_VERBOSE in the past, changed to
LL_WARNING. (all the other places that do freeClient(slave) use LL_WARNING)
2. The old style LOG_WARNING, chang it to LL_WARNING. Introduced in an
old pr (#1690).
Add NX, XX, GT, and LT flags to EXPIRE, PEXPIRE, EXPIREAT, PEXAPIREAT.
- NX - only modify the TTL if no TTL is currently set
- XX - only modify the TTL if there is a TTL currently set
- GT - only increase the TTL (considering non-volatile keys as infinite expire time)
- LT - only decrease the TTL (considering non-volatile keys as infinite expire time)
return value of the command is 0 when the operation was skipped due to one of these flags.
Signed-off-by: Ning Sun <sunng@protonmail.com>
Add two INFO metrics:
```
total_eviction_exceeded_time:69734
current_eviction_exceeded_time:10230
```
`current_eviction_exceeded_time` if greater than 0, means how much time current used memory is greater than `maxmemory`. And we are still over the maxmemory. If used memory is below `maxmemory`, this metric is reset to 0.
`total_eviction_exceeded_time` means total time used memory is greater than `maxmemory` since server startup.
The units of these two metrics are ms.
Co-authored-by: Oran Agra <oran@redislabs.com>
- SELECT and WAIT don't read or write from the keyspace (unlike DEL, EXISTS, EXPIRE, DBSIZE, KEYS, etc).
they're more similar to AUTH and HELLO (and maybe PING and COMMAND).
they only affect the current connection, not the server state, so they should be `@connection`, not `@keyspace`
- ROLE, like LASTSAVE is `@admin` (and `@dangerous` like INFO)
- ASKING, READONLY, READWRITE are `@connection` too (not `@keyspace`)
- Additionally, i'm now documenting the exact meaning of each ACL category so it's clearer which commands belong where.
There are two issues fixed in this commit:
1. we want to fail the EXEC command in case there is a watched key that's logically
expired but not yet deleted by active expire or lazy expire.
2. we saw that currently cache time is update in every `call()` (including nested calls),
this time is being also being use for the isKeyExpired comparison, we want to update
the cache time only in the first call (execCommand)
Co-authored-by: Oran Agra <oran@redislabs.com>
redis-check-aof/redis-check-rdb.
Related to #9176. Before this commit, redis-server starts as
redis-check-aof/redis-check-rdb if the directory it is started from
contains the string redis-check-aof/redis-check-rdb. We check the
executable name instead of directory.
when tracking the peak, don't reset the peak to 0, reset it to the
maximum of the current used, and the planned to be used by the current
arg.
when shrining, split the two separate conditions.
the idle time shrinking will remove all free space.
but the peak based shrinking will keep room for the current arg.
when we resize due to a peak (rahter than idle time), don't trim all
unused space, let the qbuf keep a size that's sufficient for the
currently process bulklen, and the current peak.
Co-authored-by: sundb <sundbcn@gmail.com>
Co-authored-by: yoav-steinberg <yoav@monfort.co.il>
1. querybuf_peak has not been updated correctly in readQueryFromClient.
2. qbuf shrinking uses sdsalloc instead of sdsAllocSize
see more details in issue #4983
Before this commit, redis-server starts in sentinel mode if the first startup
argument has the string redis-sentinel, so redis also starts in sentinel mode
if the directory it was started from contains the string redis-sentinel.
Now we check the executable name instead of directory.
Some examples:
1. Execute ./redis-sentinel/redis/src/redis-sentinel, starts in sentinel mode.
2. Execute ./redis-sentinel/redis/src/redis-server, starts in server mode,
but before, redis will start in sentinel mode.
3. Execute ./redis-sentinel/redis/src/redis-server --sentinel, of course, like
before, starts in sentinel mode.
In the past, the first bind address that was explicitly specified was
also used to bind outgoing connections. This could result with some
problems. For example: on some systems using `bind 127.0.0.1` would
result with outgoing connections also binding to `127.0.0.1` and failing
to connect to remote addresses.
With the recent change to the way `bind` is handled, this presented
other issues:
* The default first bind address is '*' which is not a valid address.
* We make no distinction between user-supplied config that is identical
to the default, and the default config.
This commit addresses both these issues by introducing an explicit
configuration parameter to control the bind address on outgoing
connections.
* Specifying an empty `bind ""` configuration prevents Redis from listening on any TCP port. Before this commit, such configuration was not accepted.
* Using `CONFIG GET bind` will always return an explicit configuration value. Before this commit, if a bind address was not specified the returned value was empty (which was an anomaly).
Another behavior change is that modifying the `bind` configuration to a non-default value will NO LONGER DISABLE protected-mode implicitly.
* Cleaning up the cluster interface by moving almost all related declarations into cluster.h
(no logic change -- just moving declarations/definitions around)
This initial effort leaves two items out of scope - the configuration parsing into the server
struct and the internals exposed by the clusterNode struct.
* Remove unneeded declarations of dictSds*
Ideally all the dictSds functionality would move from server.c into a dedicated module
so we can avoid the duplication in redis-benchmark/cli
* Move crc16 back into server.h, will be moved out once we create a seperate header file for
hashing functions
The initialize memory of `querybuf` is `PROTO_IOBUF_LEN(1024*16) * 2` (due to sdsMakeRoomFor being greedy), under `jemalloc`, the allocated memory will be 40k.
This will most likely result in the `querybuf` being resized when call `clientsCronResizeQueryBuffer` unless the client requests it fast enough.
Note that this bug existed even before #7875, since the condition for resizing includes the sds headers (32k+6).
## Changes
1. Use non-greedy sdsMakeRoomFor when allocating the initial query buffer (of 16k).
1. Also use non-greedy allocation when working with BIG_ARG (we won't use that extra space anyway)
2. in case we did use a greedy allocation, read as much as we can into the buffer we got (including internal frag), to reduce system calls.
3. introduce a dedicated constant for the shrinking (same value as before)
3. Add test for querybuf.
4. improve a maxmemory test by ignoring the effect of replica query buffers (can accumulate many ACKs on slow env)
5. improve a maxmemory by disabling slowlog (it will cause slight memory growth on slow env).
Today when we load the AOF on startup, the loadAppendOnlyFile checks if
the file is openning for reading.
This check is redundent (dead code) as we open the AOF file for writing at initServer,
and the file will always be existing for the loadAppendOnlyFile.
In this commit:
- remove all the exit(1) from loadAppendOnlyFile, as it is the caller
responsibility to decide what to do in case of failure.
- move the opening of the AOF file for writing, to be after we loading it.
- avoid return -ERR in DEBUG LOADAOF, when the AOF is existing but empty
This PR adds a spell checker CI action that will fail future PRs if they introduce typos and spelling mistakes.
This spell checker is based on blacklist of common spelling mistakes, so it will not catch everything,
but at least it is also unlikely to cause false positives.
Besides that, the PR also fixes many spelling mistakes and types, not all are a result of the spell checker we use.
Here's a summary of other changes:
1. Scanned the entire source code and fixes all sorts of typos and spelling mistakes (including missing or extra spaces).
2. Outdated function / variable / argument names in comments
3. Fix outdated keyspace masks error log when we check `config.notify-keyspace-events` in loadServerConfigFromString.
4. Trim the white space at the end of line in `module.c`. Check: https://github.com/redis/redis/pull/7751
5. Some outdated https link URLs.
6. Fix some outdated comment. Such as:
- In README: about the rdb, we used to said create a `thread`, change to `process`
- dbRandomKey function coment (about the dictGetRandomKey, change to dictGetFairRandomKey)
- notifyKeyspaceEvent fucntion comment (add type arg)
- Some others minor fix in comment (Most of them are incorrectly quoted by variable names)
7. Modified the error log so that users can easily distinguish between TCP and TLS in `changeBindAddr`
Till now, on replica full-sync we used to transfer absolute time for TTL,
however when a command arrived (EXPIRE or EXPIREAT),
we used to propagate it as is to replicas (possibly with relative time),
but always translate it to EXPIREAT (absolute time) to AOF.
This commit changes that and will always use absolute time for propagation.
see discussion in #8433
Furthermore, we Introduce new commands: `EXPIRETIME/PEXPIRETIME`
that allow extracting the absolute TTL time from a key.
When client breached the output buffer soft limit but then went idle,
we didn't disconnect on soft limit timeout, now we do.
Note this also resolves some sporadic test failures in due to Linux
buffering data which caused tests to fail if during the test we went
back under the soft COB limit.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: sundb <sundbcn@gmail.com>
This solves an issue reported in #8712 in which a replica would bypass
the client write pause check and cause an assertion due to executing a
write command during failover.
The fact is that we don't expect replicas to execute any command other
than maybe REPLCONF and PING, etc. but matching against the ADMIN
command flag is insufficient, so instead i just block keyspace access
for now.
When replica never successfully connect to master, server.repl_down_since
will be initialized to 0, therefore, the info master_link_down_since_seconds
was showing the current unix timestamp, which does not make much sense.
This commit fixes the issue by showing master_link_down_since_seconds to -1.
means the replica never connect to master before.
This commit also resets this variable back to 0 when a replica is turned into
a master, so that it'll behave the same if the master is later turned into a
replica again.
The implication of this change is that if some app is checking if the value is > 60
do something, like conclude the replica is stale, this could case harm (changing
a big positive number with a small one).
The bio aof fsync fd may be closed by main thread (AOFRW done handler)
and even possibly reused for another socket, pipe, or file.
This can can an EBADF or EINVAL fsync error, which will lead to -MISCONF errors failing all writes.
We just ignore these errno because aof fsync did not really fail.
We handle errno when fsyncing aof in bio, so we could know the real reason
when users get -MISCONF Errors writing to the AOF file error
Issue created with #8419
In `aof.c`, we call fsync when stop aof, and now print a log to let user know that if fail.
In `cluster.c`, we now return error, the calling function already handles these write errors.
In `redis-cli.c`, users hope to save rdb, we now print a message if fsync failed.
In `rio.c`, we now treat fsync errors like we do for write errors.
In `server.c`, we try to fsync aof file when shutdown redis, we only can print one log if fail.
In `bio.c`, if failing to fsync aof file, we will set `aof_bio_fsync_status` to error , and reject writing just like last writing aof error, moreover also set INFO command field `aof_last_write_status` to error.
The implications of this change is just that in the past when a config file was missing,
in some cases it was exiting before printing the sever startup prints and sometimes after,
and now it'll always exit before printing them.
The 'sentinel replicas <master>' command will ignore replicas with
`replica-announced` set to no.
The goal of disabling the config setting replica-announced is to allow ghost
replicas. The replica is in the cluster, synchronize with its master, can be
promoted to master and is not exposed to sentinel clients. This way, it is
acting as a live backup or living ghost.
In addition, to prevent the replica to be promoted as master, set
replica-priority to 0.
Add publish channel permissions check in processCommand.
processCommand didn't check publish channel permissions, so we can
queue a publish command in a transaction. But when exec the transaction,
it will fail with -NOPERM.
We also union keys/commands/channels permissions check togegher in
ACLCheckAllPerm. Remove pubsubCheckACLPermissionsOrReply in
publishCommand/subscribeCommand/psubscribeCommand. Always
check permissions in processCommand/execCommand/
luaRedisGenericCommand.
* SLOWLOG didn't record anything for blocked commands because the client
was reset and argv was already empty. there was a fix for this issue
specifically for modules, now it works for all blocked clients.
* The original command argv (before being re-written) was also reset
before adding the slowlog on behalf of the blocked command.
* Latency monitor is now updated regardless of the slowlog flags of the
command or its execution (their purpose is to hide sensitive info from
the slowlog, not hide the fact the latency happened).
* Latency monitor now uses real_cmd rather than c->cmd (which may be
different if the command got re-written, e.g. GEOADD)
Changes:
* Unify shared code between slowlog insertion in call() and
updateStatsOnUnblock(), hopefully prevent future bugs from happening
due to the later being overlooked.
* Reset CLIENT_PREVENT_LOGGING in resetClient rather than after command
processing.
* Add a test for SLOWLOG and BLPOP
Notes:
- real_cmd == c->lastcmd, except inside MULTI and Lua.
- blocked commands never happen in these cases (MULTI / Lua)
- real_cmd == c->cmd, except for when the command is rewritten (e.g.
GEOADD)
- blocked commands (currently) are never rewritten
- other than the command's CLIENT_PREVENT_LOGGING, and the
execution flag CLIENT_PREVENT_LOGGING, other cases that we want to
avoid slowlog are on AOF loading (specifically CMD_CALL_SLOWLOG will
be off when executed from execCommand that runs from an AOF)
Reading CoW from /proc/<pid>/smaps can be slow with large processes on
some platforms.
This measures the time it takes to read CoW info and limits the duty
cycle of future updates to roughly 1/100.
As current_cow_size no longer represnets a current, fixed interval value
there is also a new current_cow_size_age field that provides information
about the age of the size value, in seconds.
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.
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 641c64ada1
Fixes: commit dfb598cf33
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
`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)
When no connected clients variables stopped being updated instead of being zeroed over time.
The other changes are cleanup and optimization (avoiding an unnecessary division per client)
Add ability to modify port, tls-port and bind configurations by CONFIG SET command.
To simplify the code and make it cleaner, a new structure
added, socketFds, which contains the file descriptors array and its counter,
and used for TCP, TLS and Cluster sockets file descriptors.
Originally this was limited to IPv6 address length, but effectively it
has been used for host names and now that Sentinel accepts that as well
we need to be able to store full hostnames.
Fixes#8507
* Adding current_save_keys_total and current_save_keys_processed info fields.
Present in replication, BGSAVE and AOFRW.
* Changing RM_SendChildCOWInfo() to RM_SendChildHeartbeat(double progress)
* Adding new info field current_fork_perc. Present in Replication, BGSAVE, AOFRW,
and module forks.
This commit enables tracking time of the background tasks and on replies,
opening the door for properly tracking commands that rely on blocking / background
work via the slowlog, latency history, and commandstats.
Some notes:
- The time spent blocked waiting for key changes, or blocked on synchronous
replication is not accounted for.
- **This commit does not affect latency tracking of commands that are non-blocking
or do not have background work.** ( meaning that it all stays the same with exception to
`BZPOPMIN`,`BZPOPMAX`,`BRPOP`,`BLPOP`, etc... and module's commands that rely
on background threads ).
- Specifically for latency history command we've added a new event class named
`command-unblocking` that will enable latency monitoring on commands that spawn
background threads to do the work.
- For blocking commands we're now considering the total time of a command as the
time spent on call() + the time spent on replying when unblocked.
- For Modules commands that rely on background threads we're now considering the
total time of a command as the time spent on call (main thread) + the time spent on
the background thread ( if marked within `RedisModule_MeasureTimeStart()` and
`RedisModule_MeasureTimeEnd()` ) + the time spent on replying (main thread)
To test for this feature we've added a `unit/moduleapi/blockonbackground` test that relies on
a module that blocks the client and sleeps on the background for a given time.
- check blocked command that uses RedisModule_MeasureTimeStart() is tracking background time
- check blocked command that uses RedisModule_MeasureTimeStart() is tracking background time even in timeout
- check blocked command with multiple calls RedisModule_MeasureTimeStart() is tracking the total background time
- check blocked command without calling RedisModule_MeasureTimeStart() is not reporting background time
New commands:
`HRANDFIELD [<count> [WITHVALUES]]`
`ZRANDMEMBER [<count> [WITHSCORES]]`
Algorithms are similar to the one in SRANDMEMBER.
Both return a simple bulk response when no arguments are given, and an array otherwise.
In case values/scores are requested, RESP2 returns a long array, and RESP3 a nested array.
note: in all 3 commands, the only option that also provides random order is the one with negative count.
Changes to SRANDMEMBER
* Optimization when count is 1, we can use the more efficient algorithm of non-unique random
* optimization: work with sds strings rather than robj
Other changes:
* zzlGetScore: when zset needs to convert string to double, we use safer memcpy (in
case the buffer is too small)
* Solve a "bug" in SRANDMEMBER test: it intended to test a positive count (case 3 or
case 4) and by accident used a negative count
Co-authored-by: xinluton <xinluton@qq.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
The key point is how to recover from last AOF write error, for example:
1. start redis with appendonly yes, and append some write commands
2. short write or something else error happen, `server.aof_last_write_status` changed to `C_ERR`, now redis doesn't accept write commands
3. execute `CONFIG SET appendonly no` to avoid the above problem, now redis can accept write commands again
4. disk error resolved, and execute `CONFIG SET appendonly yes` to reopen AOF, but `server.aof_last_write_status` cannot be changed to `C_OK` (if background aof rewrite run less then 1 second, it will free `server.aof_buf` and then serverCron cannot fix `aof_last_write_status`), then redis cannot accept write commands forever.
This PR use a simple way to fix it:
1. just free `server.aof_buf` when stop appendonly to save memory, if error happens in `flushAppendOnlyFile(1)`, the `server.aof_buf` may contains some data which has not be written to aof, I think we can ignore it because we turn off the appendonly.
2. reset fsync status after stop appendonly and call `flushAppendOnlyFile` only when `aof_state` is ON
3. reset `server.last_write_status` when reopen aof to accept write commands
if option `set-proc-title' is no, then do nothing for proc title.
The reason has been explained long ago, see following:
We update redis to 2.8.8, then found there are some side effect when
redis always change the process title.
We run several slave instance on one computer, and all these salves
listen on unix socket only, then ps will show:
1 S redis 18036 1 0 80 0 - 56130 ep_pol 14:02 ? 00:00:31 /usr/sbin/redis-server *:0
1 S redis 23949 1 0 80 0 - 11074 ep_pol 15:41 ? 00:00:00 /usr/sbin/redis-server *:0
for redis 2.6 the output of ps is like following:
1 S redis 18036 1 0 80 0 - 56130 ep_pol 14:02 ? 00:00:31 /usr/sbin/redis-server /etc/redis/a.conf
1 S redis 23949 1 0 80 0 - 11074 ep_pol 15:41 ? 00:00:00 /usr/sbin/redis-server /etc/redis/b.conf
Later is more informational in our case. The situation
is worse when we manage the config and process running
state by salt. Salt check the process by running "ps |
grep SIG" (for Gentoo System) to check the running
state, where SIG is the string to search for when
looking for the service process with ps. Previously, we
define sig as "/usr/sbin/redis-server
/etc/redis/a.conf". Since the ps output is identical for
our case, so we have no way to check the state of
specified redis instance.
So, for our case, we prefer the old behavior, i.e, do
not change the process title for the main redis process.
Or add an option such as "set-proc-title [yes|no]" to
control this behavior.
Co-authored-by: Yossi Gottlieb <yossigo@gmail.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
At least in one case the arm64 cow kernel bug test triggers an assert, which is a problem because it cannot be ignored like cases where the bug is found.
On older systems (Linux <4.5) madvise fails because MADV_FREE is not supported. We treat these failures as an indication the system is not affected.
Fixes#8351, #8406
This commit introduces two new command and two options for an existing command
GETEX <key> [PERSIST][EX seconds][PX milliseconds] [EXAT seconds-timestamp]
[PXAT milliseconds-timestamp]
The getexCommand() function implements extended options and variants of the GET
command. Unlike GET command this command is not read-only. Only one of the options
can be used at a given time.
1. PERSIST removes any TTL associated with the key.
2. EX Set expiry TTL in seconds.
3. PX Set expiry TTL in milliseconds.
4. EXAT Same like EX instead of specifying the number of seconds representing the
TTL (time to live), it takes an absolute Unix timestamp
5. PXAT Same like PX instead of specifying the number of milliseconds representing the
TTL (time to live), it takes an absolute Unix timestamp
Command would return either the bulk string, error or nil.
GETDEL <key>
Would delete the key after getting.
SET key value [NX] [XX] [KEEPTTL] [GET] [EX <seconds>] [PX <milliseconds>]
[EXAT <seconds-timestamp>][PXAT <milliseconds-timestamp>]
Two new options added here are EXAT and PXAT
Key implementation notes
- `SET` with `PX/EX/EXAT/PXAT` is always translated to `PXAT` in `AOF`. When relative time is
specified (`PX/EX`), replication will always use `PX`.
- `setexCommand` and `psetexCommand` would no longer need translation in `feedAppendOnlyFile`
as they are modified to invoke `setGenericCommand ` with appropriate flags which will take care of
correct AOF translation.
- `GETEX` without any optional argument behaves like `GET`.
- `GETEX` command is never propagated, It is either propagated as `PEXPIRE[AT], or PERSIST`.
- `GETDEL` command is propagated as `DEL`
- Combined the validation for `SET` and `GETEX` arguments.
- Test cases to validate AOF/Replication propagation
This commit fixes a well known and an annoying issue in Sentinel mode.
Cause of this issue:
Currently, Redis rewrite process works well in server mode, however in sentinel mode,
the sentinel config has variant semantics for different configurations, in example configuration
https://github.com/redis/redis/blob/unstable/sentinel.conf, we put comments on these.
However the rewrite process only treat the sentinel config as a single option. During rewrite
process, it will mess up with the lines and comments.
Approaches:
In order to solve this issue, we need to differentiate different subconfig options in sentinel separately,
for example, sentinel monitor <master-name> <ip> <redis-port> <quorum>
we can treat it as sentinel monitor option, instead of the sentinel option.
This commit also fixes the dependency issue when putting configurations in sentinel.conf.
For example before this commit,we must put
`sentinel monitor <master-name> <ip> <redis-port> <quorum>` before
`sentinel auth-pass <master-name> <password>` for a single master,
otherwise the server cannot start and will return error. This commit fixes this issue, as long as
the monitoring master was configured, no matter the sequence is, the sentinel can start and run properly.
Fixes a regression introduced due to a new (safer) way of rewriting configuration files. In the past the file was simply overwritten (same inode), but now Redis creates a new temporary file and later renames it over the old one.
The temp file typically gets created with 0600 permissions so we later fchmod it to fix that. Unlike open with O_CREAT, fchmod doesn't consider umask so we have to do that explicitly.
Fixes#8369
The output for COMMAND command was wrong for some commands.
clients can use firstkey,lastkey,step to find (some) key name arguments, and the
"movablekeys" flag to know that they can't know all (or any) of the key name arguments.
These commands had the wrong output:
1. GEORADIUS*_RO used to have "movablekeys" (which it doesn't really need)
2. XREAD and XREADGROUP used to have (1,1,1). but that's completely wrong.
3. Z*STORE used to have (0,0,0) but it can at lest give the index of the dstkey (1,1,1)
Sentinel uses execve to run scripts, so it needs to use FD_CLOEXEC
on all file descriptors, so that they're not accessible by the script it runs.
This commit includes a change to the sentinel tests, which verifies no
FDs are left opened when the script is executed.
This fixes three issues:
1. Using debug SLEEP was impacting the subsequent test, and causing it to pass reliably even though it should have failed. There was exactly 5 seconds of artificial pause (after 1000, wait 3000, wait 1000) between the debug sleep 5 and when we needed to unblock the client in the subsequent test. Now the test properly makes sure the client is unblocked, and the subsequent test is fixed.
2. Minor, the client pause types were using & comparisons instead of ==, since it was previously a flag.
3. Test is faster now that some of the hand wavy time is removed.
