The keyspec API is not yet released and there is a plan to change it
in #10108, which is going to be included in RC2. Therefore, we hide
it in RC1 to avoid introducing a breaking change in RC2.
Co-authored-by: Oran Agra <oran@redislabs.com>
Summary of changes:
1. Rename `redisCommand->name` to `redisCommand->declared_name`, it is a
const char * for native commands and SDS for module commands.
2. Store the [sub]command fullname in `redisCommand->fullname` (sds).
3. List subcommands in `ACL CAT`
4. List subcommands in `COMMAND LIST`
5. `moduleUnregisterCommands` now will also free the module subcommands.
6. RM_GetCurrentCommandName returns full command name
Other changes:
1. Add `addReplyErrorArity` and `addReplyErrorExpireTime`
2. Remove `getFullCommandName` function that now is useless.
3. Some cleanups about `fullname` since now it is SDS.
4. Delete `populateSingleCommand` function from server.h that is useless.
5. Added tests to cover this change.
6. Add some module unload tests and fix the leaks
7. Make error messages uniform, make sure they always contain the full command
name and that it's quoted.
7. Fixes some typos
see the history in #9504, fixes#10124
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: guybe7 <guy.benoish@redislabs.com>
* Implemented selectors which provide multiple different sets of permissions to users
* Implemented key based permissions
* Added a new ACL dry-run command to test permissions before execution
* Updated module APIs to support checking key based permissions
Co-authored-by: Oran Agra <oran@redislabs.com>
Some modules might perform a long-running logic in different stages of Redis lifetime, for example:
* command execution
* RDB loading
* thread safe context
During this long-running logic Redis is not responsive.
This PR offers
1. An API to process events while a busy command is running (`RM_Yield`)
2. A new flag (`ALLOW_BUSY`) to mark the commands that should be handled during busy
jobs which can also be used by modules (`allow-busy`)
3. In slow commands and thread safe contexts, this flag will start rejecting commands with -BUSY only
after `busy-reply-threshold`
4. During loading (`rdb_load` callback), it'll process events right away (not wait for `busy-reply-threshold`),
but either way, the processing is throttled to the server hz rate.
5. Allow modules to Yield to redis background tasks, but not to client commands
* rename `script-time-limit` to `busy-reply-threshold` (an alias to the pre-7.0 `lua-time-limit`)
Co-authored-by: Oran Agra <oran@redislabs.com>
The new ACL key based permissions in #9974 require the key-specs (#8324) to have more
explicit flags rather than just READ and WRITE. See discussion in #10040
This PR defines two groups of flags:
One about how redis internally handles the key (mutually-exclusive).
The other is about the logical operation done from the user's point of view (3 mutually exclusive
write flags, and one read flag, all optional).
In both groups, if we can't explicitly flag something as explicit read-only, delete-only, or
insert-only, we flag it as `RW` or `UPDATE`.
here's the definition from the code:
```
/* Key-spec flags *
* -------------- */
/* The following refer what the command actually does with the value or metadata
* of the key, and not necessarily the user data or how it affects it.
* Each key-spec may must have exaclty one of these. Any operation that's not
* distinctly deletion, overwrite or read-only would be marked as RW. */
#define CMD_KEY_RO (1ULL<<0) /* Read-Only - Reads the value of the key, but
* doesn't necessarily returns it. */
#define CMD_KEY_RW (1ULL<<1) /* Read-Write - Modifies the data stored in the
* value of the key or its metadata. */
#define CMD_KEY_OW (1ULL<<2) /* Overwrite - Overwrites the data stored in
* the value of the key. */
#define CMD_KEY_RM (1ULL<<3) /* Deletes the key. */
/* The follwing refer to user data inside the value of the key, not the metadata
* like LRU, type, cardinality. It refers to the logical operation on the user's
* data (actual input strings / TTL), being used / returned / copied / changed,
* It doesn't refer to modification or returning of metadata (like type, count,
* presence of data). Any write that's not INSERT or DELETE, would be an UPADTE.
* Each key-spec may have one of the writes with or without access, or none: */
#define CMD_KEY_ACCESS (1ULL<<4) /* Returns, copies or uses the user data from
* the value of the key. */
#define CMD_KEY_UPDATE (1ULL<<5) /* Updates data to the value, new value may
* depend on the old value. */
#define CMD_KEY_INSERT (1ULL<<6) /* Adds data to the value with no chance of,
* modification or deletion of existing data. */
#define CMD_KEY_DELETE (1ULL<<7) /* Explicitly deletes some content
* from the value of the key. */
```
Unrelated changes:
- generate-command-code.py is only compatible with python3 (modified the shabang)
- generate-command-code.py print file on json parsing error
- rename `shard_channel` key-spec flag to just `channel`.
- add INCOMPLETE flag in input spec of SORT and SORT_RO
When I used C++ to develop a redis module. i used `string.data()` as the second parameter `ele`
of `RedisModule_DigestAddStringBuffer`, but there is a warning, since we never change the `ele`,
i think we should use `const char` for it.
This PR adds const to just a handful of module APIs that required it, all not very widely used.
The implication is a breaking change in terms of compilation error that's easy to resolve, and no ABI impact.
The affected APIs are around Digest, Info injection, and Cluster bus messages.
Modules can now register sockets/pipe to the Redis main thread event loop and do network operations asynchronously. Previously, modules had to maintain an event loop and another thread for asynchronous network operations.
Also, if a module is calling API functions after doing some network operations, it had to synchronize its event loop thread's access with Redis main thread by locking the GIL, causing contention on the lock. After this commit, no synchronization is needed as module can operate in Redis main thread context. So, this commit may improve the performance for some use cases.
Added three functions to the module API:
* RedisModule_EventLoopAdd(int fd, int mask, RedisModuleEventLoopFunc func, void *user_data)
* RedisModule_EventLoopDel(int fd, int mask)
* RedisModule_EventLoopAddOneShot(RedisModuleEventLoopOneShotFunc func, void *user_data) - This function can be called from other threads to trigger callback on Redis main thread. Callback will be triggered only once. If Redis main thread is sleeping, this call will wake up the Redis main thread.
Event loop callbacks are called by Redis main thread after locking the GIL. Inside callbacks, modules can operate as if they are holding the GIL.
Added REDISMODULE_EVENT_EVENTLOOP event with two subevents:
* REDISMODULE_SUBEVENT_EVENTLOOP_BEFORE_SLEEP
* REDISMODULE_SUBEVENT_EVENTLOOP_AFTER_SLEEP
These events are for modules that want to participate in the before and after sleep action. e.g It might be useful to implement batching : Read data from the network, write all to a file in one go on BEFORE_SLEEP event.
Force create a BASE file (use a foreground `rewriteAppendOnlyFile`) when redis starts from an
empty data set and `appendonly` is yes.
The reasoning is that normally, after redis is running for some time, and the AOF has gone though
a few rewrites, there's always a base rdb file. and the scenario where the base file is missing, is
kinda rare (happens only at empty startup), so this change normalizes it.
But more importantly, there are or could be some complex modules that are started with some
configuration, when they create persistence they write that configuration to RDB AUX fields, so
that can can always know with which configuration the persistence file they're loading was
created (could be critical). there is (was) one scenario in which they could load their persisted data,
and that configuration was missing, and this change fixes it.
Add a new module event: REDISMODULE_SUBEVENT_PERSISTENCE_SYNC_AOF_START, similar to
REDISMODULE_SUBEVENT_PERSISTENCE_AOF_START which is async.
Co-authored-by: Oran Agra <oran@redislabs.com>
The mess:
Some parts use alsoPropagate for late propagation, others using an immediate one (propagate()),
causing edge cases, ugly/hacky code, and the tendency for bugs
The basic idea is that all commands are propagated via alsoPropagate (i.e. added to a list) and the
top-most call() is responsible for going over that list and actually propagating them (and wrapping
them in MULTI/EXEC if there's more than one command). This is done in the new function,
propagatePendingCommands.
Callers to propagatePendingCommands:
1. top-most call() (we want all nested call()s to add to the also_propagate array and just the top-most
one to propagate them) - via `afterCommand`
2. handleClientsBlockedOnKeys: it is out of call() context and it may propagate stuff - via `afterCommand`.
3. handleClientsBlockedOnKeys edge case: if the looked-up key is already expired, we will propagate the
expire but will not unblock any client so `afterCommand` isn't called. in that case, we have to propagate
the deletion explicitly.
4. cron stuff: active-expire and eviction may also propagate stuff
5. modules: the module API allows to propagate stuff from just about anywhere (timers, keyspace notifications,
threads). I could have tried to catch all the out-of-call-context places but it seemed easier to handle it in one
place: when we free the context. in the spirit of what was done in call(), only the top-most freeing of a module
context may cause propagation.
6. modules: when using a thread-safe ctx it's not clear when/if the ctx will be freed. we do know that the module
must lock the GIL before calling RM_Replicate/RM_Call so we propagate the pending commands when
releasing the GIL.
A "known limitation", which were actually a bug, was fixed because of this commit (see propagate.tcl):
When using a mix of RM_Call with `!` and RM_Replicate, the command would propagate out-of-order:
first all the commands from RM_Call, and then the ones from RM_Replicate
Another thing worth mentioning is that if, in the past, a client would issue a MULTI/EXEC with just one
write command the server would blindly propagate the MULTI/EXEC too, even though it's redundant.
not anymore.
This commit renames propagate() to propagateNow() in order to cause conflicts in pending PRs.
propagatePendingCommands is the only caller of propagateNow, which is now a static, internal helper function.
Optimizations:
1. alsoPropagate will not add stuff to also_propagate if there's no AOF and replicas
2. alsoPropagate reallocs also_propagagte exponentially, to save calls to memmove
Bugfixes:
1. CONFIG SET can create evictions, sending notifications which can cause to dirty++ with modules.
we need to prevent it from propagating to AOF/replicas
2. We need to set current_client in RM_Call. buggy scenario:
- CONFIG SET maxmemory, eviction notifications, module hook calls RM_Call
- assertion in lookupKey crashes, because current_client has CONFIG SET, which isn't CMD_WRITE
3. minor: in eviction, call propagateDeletion after notification, like active-expire and all commands
(we always send a notification before propagating the command)
Delete the hardcoded command table and replace it with an auto-generated table, based
on a JSON file that describes the commands (each command must have a JSON file).
These JSON files are the SSOT of everything there is to know about Redis commands,
and it is reflected fully in COMMAND INFO.
These JSON files are used to generate commands.c (using a python script), which is then
committed to the repo and compiled.
The purpose is:
* Clients and proxies will be able to get much more info from redis, instead of relying on hard coded logic.
* drop the dependency between Redis-user and the commands.json in redis-doc.
* delete help.h and have redis-cli learn everything it needs to know just by issuing COMMAND (will be
done in a separate PR)
* redis.io should stop using commands.json and learn everything from Redis (ultimately one of the release
artifacts should be a large JSON, containing all the information about all of the commands, which will be
generated from COMMAND's reply)
* the byproduct of this is:
* module commands will be able to provide that info and possibly be more of a first-class citizens
* in theory, one may be able to generate a redis client library for a strictly typed language, by using this info.
### Interface changes
#### COMMAND INFO's reply change (and arg-less COMMAND)
Before this commit the reply at index 7 contained the key-specs list
and reply at index 8 contained the sub-commands list (Both unreleased).
Now, reply at index 7 is a map of:
- summary - short command description
- since - debut version
- group - command group
- complexity - complexity string
- doc-flags - flags used for documentation (e.g. "deprecated")
- deprecated-since - if deprecated, from which version?
- replaced-by - if deprecated, which command replaced it?
- history - a list of (version, what-changed) tuples
- hints - a list of strings, meant to provide hints for clients/proxies. see https://github.com/redis/redis/issues/9876
- arguments - an array of arguments. each element is a map, with the possibility of nesting (sub-arguments)
- key-specs - an array of keys specs (already in unstable, just changed location)
- subcommands - a list of sub-commands (already in unstable, just changed location)
- reply-schema - will be added in the future (see https://github.com/redis/redis/issues/9845)
more details on these can be found in https://github.com/redis/redis-doc/pull/1697
only the first three fields are mandatory
#### API changes (unreleased API obviously)
now they take RedisModuleCommand opaque pointer instead of looking up the command by name
- RM_CreateSubcommand
- RM_AddCommandKeySpec
- RM_SetCommandKeySpecBeginSearchIndex
- RM_SetCommandKeySpecBeginSearchKeyword
- RM_SetCommandKeySpecFindKeysRange
- RM_SetCommandKeySpecFindKeysKeynum
Currently, we did not add module API to provide additional information about their commands because
we couldn't agree on how the API should look like, see https://github.com/redis/redis/issues/9944.
### Somehow related changes
1. Literals should be in uppercase while placeholder in lowercase. Now all the GEO* command
will be documented with M|KM|FT|MI and can take both lowercase and uppercase
### Unrelated changes
1. Bugfix: no_madaory_keys was absent in COMMAND's reply
2. expose CMD_MODULE as "module" via COMMAND
3. have a dedicated uint64 for ACL categories (instead of having them in the same uint64 as command flags)
Co-authored-by: Itamar Haber <itamar@garantiadata.com>
Writable replicas now no longer use the values of expired keys. Expired keys are
deleted when lookupKeyWrite() is used, even on a writable replica. Previously,
writable replicas could use the value of an expired key in write commands such
as INCR, SUNIONSTORE, etc..
This commit also sorts out the mess around the functions lookupKeyRead() and
lookupKeyWrite() so they now indicate what we intend to do with the key and
are not affected by the command calling them.
Multi-key commands like SUNIONSTORE, ZUNIONSTORE, COPY and SORT with the
store option now use lookupKeyRead() for the keys they're reading from (which will
not allow reading from logically expired keys).
This commit also fixes a bug where PFCOUNT could return a value of an
expired key.
Test modules commands have their readonly and write flags updated to correctly
reflect their lookups for reading or writing. Modules are not required to
correctly reflect this in their command flags, but this change is made for
consistency since the tests serve as usage examples.
Fixes#6842. Fixes#7475.
Some people complain that QUIT is missing from help/command table.
Not appearing in COMMAND command, command stats, ACL, etc.
and instead, there's a hack in processCommand with a comment that looks outdated.
Note that it is [documented](https://redis.io/commands/quit)
At the same time, HOST: and POST are there in the command table although these are not real commands.
They would appear in the COMMAND command, and even in commandstats.
Other changes:
1. Initialize the static logged_time static var in securityWarningCommand
2. add `no-auth` flag to RESET so it can always be executed.
For diskless replication in swapdb mode, considering we already spend replica memory
having a backup of current db to restore in case of failure, we can have the following benefits
by instead swapping database only in case we succeeded in transferring db from master:
- Avoid `LOADING` response during failed and successful synchronization for cases where the
replica is already up and running with data.
- Faster total time of diskless replication, because now we're moving from Transfer + Flush + Load
time to Transfer + Load only. Flushing the tempDb is done asynchronously after swapping.
- This could be implemented also for disk replication with similar benefits if consumers are willing
to spend the extra memory usage.
General notes:
- The concept of `backupDb` becomes `tempDb` for clarity.
- Async loading mode will only kick in if the replica is syncing from a master that has the same
repl-id the one it had before. i.e. the data it's getting belongs to a different time of the same timeline.
- New property in INFO: `async_loading` to differentiate from the blocking loading
- Slot to Key mapping is now a field of `redisDb` as it's more natural to access it from both server.db
and the tempDb that is passed around.
- Because this is affecting replicas only, we assume that if they are not readonly and write commands
during replication, they are lost after SYNC same way as before, but we're still denying CONFIG SET
here anyways to avoid complications.
Considerations for review:
- We have many cases where server.loading flag is used and even though I tried my best, there may
be cases where async_loading should be checked as well and cases where it shouldn't (would require
very good understanding of whole code)
- Several places that had different behavior depending on the loading flag where actually meant to just
handle commands coming from the AOF client differently than ones coming from real clients, changed
to check CLIENT_ID_AOF instead.
**Additional for Release Notes**
- Bugfix - server.dirty was not incremented for any kind of diskless replication, as effect it wouldn't
contribute on triggering next database SAVE
- New flag for RM_GetContextFlags module API: REDISMODULE_CTX_FLAGS_ASYNC_LOADING
- Deprecated RedisModuleEvent_ReplBackup. Starting from Redis 7.0, we don't fire this event.
Instead, we have the new RedisModuleEvent_ReplAsyncLoad holding 3 sub-events: STARTED,
ABORTED and COMPLETED.
- New module flag REDISMODULE_OPTIONS_HANDLE_REPL_ASYNC_LOAD for RedisModule_SetModuleOptions
to allow modules to declare they support the diskless replication with async loading (when absent, we fall
back to disk-based loading).
Co-authored-by: Eduardo Semprebon <edus@saxobank.com>
Co-authored-by: Oran Agra <oran@redislabs.com>
The module test in reply.tcl was introduced by #8521 but didn't run until recently (see #9639)
and then it started failing with valgrind.
This is because valgrind uses 64 bit long double (unlike most other platforms that have at least 80 bits)
But besides valgrind, the tests where also incompatible with ARM32, which also uses 64 bit long doubles.
We now use appropriate value to avoid issues with either valgrind or ARM32
In all the double tests, i use 3.141, which is safe since since addReplyDouble uses
`%.17Lg` which is able to represent this value without adding any digits due to precision loss.
In the long double, since we use `%.17Lf` in ld2string, it preserves 17 significant
digits, rather than 17 digit after the decimal point (like in `%.17Lg`).
So to make these similar, i use value lower than 1 (no digits left of
the period)
Lastly, we have the same issue with TCL (no long doubles) so we read
raw protocol in that test.
Note that the only error before this fix (in both valgrind and ARM32 is this:
```
*** [err]: RM_ReplyWithLongDouble: a float reply in tests/unit/moduleapi/reply.tcl
Expected '3.141' to be equal to '3.14100000000000001' (context: type eval line 2 cmd {assert_equal 3.141 [r rw.longdouble 3.141]} proc ::test)
```
so the changes to debug.c and scripting.tcl aren't really needed, but i consider them a cleanup
(i.e. scripting.c validated a different constant than the one that's sent to it from debug.c).
Another unrelated change is to add the RESP version to the repeated tests in reply.tcl
This solves several problems in a more elegant way:
* No need to explicitly use `-lc` on x86_64 when building with `-m32`.
* Avoids issues with undefined floating point emulation funcs on ARM.
Let modules use additional type of RESP3 response (unused by redis so far)
Also fix tests that where introduced in #8521 but didn't actually run.
Co-authored-by: Oran Agra <oran@redislabs.com>
Before this commit, module blocked clients did not carry through the original RESP version, resulting with RESP3 clients receiving unexpected RESP2 replies.
## Intro
The purpose is to allow having different flags/ACL categories for
subcommands (Example: CONFIG GET is ok-loading but CONFIG SET isn't)
We create a small command table for every command that has subcommands
and each subcommand has its own flags, etc. (same as a "regular" command)
This commit also unites the Redis and the Sentinel command tables
## Affected commands
CONFIG
Used to have "admin ok-loading ok-stale no-script"
Changes:
1. Dropped "ok-loading" in all except GET (this doesn't change behavior since
there were checks in the code doing that)
XINFO
Used to have "read-only random"
Changes:
1. Dropped "random" in all except CONSUMERS
XGROUP
Used to have "write use-memory"
Changes:
1. Dropped "use-memory" in all except CREATE and CREATECONSUMER
COMMAND
No changes.
MEMORY
Used to have "random read-only"
Changes:
1. Dropped "random" in PURGE and USAGE
ACL
Used to have "admin no-script ok-loading ok-stale"
Changes:
1. Dropped "admin" in WHOAMI, GENPASS, and CAT
LATENCY
No changes.
MODULE
No changes.
SLOWLOG
Used to have "admin random ok-loading ok-stale"
Changes:
1. Dropped "random" in RESET
OBJECT
Used to have "read-only random"
Changes:
1. Dropped "random" in ENCODING and REFCOUNT
SCRIPT
Used to have "may-replicate no-script"
Changes:
1. Dropped "may-replicate" in all except FLUSH and LOAD
CLIENT
Used to have "admin no-script random ok-loading ok-stale"
Changes:
1. Dropped "random" in all except INFO and LIST
2. Dropped "admin" in ID, TRACKING, CACHING, GETREDIR, INFO, SETNAME, GETNAME, and REPLY
STRALGO
No changes.
PUBSUB
No changes.
CLUSTER
Changes:
1. Dropped "admin in countkeysinslots, getkeysinslot, info, nodes, keyslot, myid, and slots
SENTINEL
No changes.
(note that DEBUG also fits, but we decided not to convert it since it's for
debugging and anyway undocumented)
## New sub-command
This commit adds another element to the per-command output of COMMAND,
describing the list of subcommands, if any (in the same structure as "regular" commands)
Also, it adds a new subcommand:
```
COMMAND LIST [FILTERBY (MODULE <module-name>|ACLCAT <cat>|PATTERN <pattern>)]
```
which returns a set of all commands (unless filters), but excluding subcommands.
## Module API
A new module API, RM_CreateSubcommand, was added, in order to allow
module writer to define subcommands
## ACL changes:
1. Now, that each subcommand is actually a command, each has its own ACL id.
2. The old mechanism of allowed_subcommands is redundant
(blocking/allowing a subcommand is the same as blocking/allowing a regular command),
but we had to keep it, to support the widespread usage of allowed_subcommands
to block commands with certain args, that aren't subcommands (e.g. "-select +select|0").
3. I have renamed allowed_subcommands to allowed_firstargs to emphasize the difference.
4. Because subcommands are commands in ACL too, you can now use "-" to block subcommands
(e.g. "+client -client|kill"), which wasn't possible in the past.
5. It is also possible to use the allowed_firstargs mechanism with subcommand.
For example: `+config -config|set +config|set|loglevel` will block all CONFIG SET except
for setting the log level.
6. All of the ACL changes above required some amount of refactoring.
## Misc
1. There are two approaches: Either each subcommand has its own function or all
subcommands use the same function, determining what to do according to argv[0].
For now, I took the former approaches only with CONFIG and COMMAND,
while other commands use the latter approach (for smaller blamelog diff).
2. Deleted memoryGetKeys: It is no longer needed because MEMORY USAGE now uses the "range" key spec.
4. Bugfix: GETNAME was missing from CLIENT's help message.
5. Sentinel and Redis now use the same table, with the same function pointer.
Some commands have a different implementation in Sentinel, so we redirect
them (these are ROLE, PUBLISH, and INFO).
6. Command stats now show the stats per subcommand (e.g. instead of stats just
for "config" you will have stats for "config|set", "config|get", etc.)
7. It is now possible to use COMMAND directly on subcommands:
COMMAND INFO CONFIG|GET (The pipeline syntax was inspired from ACL, and
can be used in functions lookupCommandBySds and lookupCommandByCString)
8. STRALGO is now a container command (has "help")
## Breaking changes:
1. Command stats now show the stats per subcommand (see (5) above)
Prevent clients from being blocked forever in cluster when they block with their own module command
and the hash slot is migrated to another master at the same time.
These will get a redirection message when unblocked.
Also, release clients blocked on module commands when cluster is down (same as other blocked clients)
This commit adds basic tests for the main (non-cluster) redis test infra that test the cluster.
This was done because the cluster test infra can't handle some common test features,
but most importantly we only build the test modules with the non-cluster test suite.
note that rather than really supporting cluster operations by the test infra, it was added (as dup code)
in two files, one for module tests and one for non-modules tests, maybe in the future we'll refactor that.
Co-authored-by: Oran Agra <oran@redislabs.com>
This is useful for approximating size computation of complex module types.
Note that the mem_usage2 callback is new and has not been released yet, which is why we can modify it.
This commit makes it possible to explicitly trim the allocation of a
RedisModuleString.
Currently, Redis automatically trims strings that have been retained by
a module command when it returns. However, this is not thread safe and
may result with corruption in threaded modules.
Supporting explicit trimming offers a backwards compatible workaround to
this problem.
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.
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
List functions operating on elements by index:
* RM_ListGet
* RM_ListSet
* RM_ListInsert
* RM_ListDelete
Iteration is done using a simple for loop over indices.
The index based functions use an internal iterator as an optimization.
This is explained in the docs:
```
* Many of the list functions access elements by index. Since a list is in
* essence a doubly-linked list, accessing elements by index is generally an
* O(N) operation. However, if elements are accessed sequentially or with
* indices close together, the functions are optimized to seek the index from
* the previous index, rather than seeking from the ends of the list.
*
* This enables iteration to be done efficiently using a simple for loop:
*
* long n = RM_ValueLength(key);
* for (long i = 0; i < n; i++) {
* RedisModuleString *elem = RedisModule_ListGet(key, i);
* // Do stuff...
* }
```
Before #9497, before redis-server was shut down, we did not manually shut down all the clients,
which would have prevented valgrind from detecting a memory leak in the client's argc.
When parsing an array type reply, ctx will be lost when recursively parsing its
elements, which will cause a memory leak in automemory mode.
This is a result of the changes in #9202
Add test for callReplyParseCollection fix
Fix test introduced in #9202 that failed on 32bit CI.
The failure was due to a wrong double comparison.
Change code to stringify the double first and then compare.
## Current state
1. Lua has its own parser that handles parsing `reds.call` replies and translates them
to Lua objects that can be used by the user Lua code. The parser partially handles
resp3 (missing big number, verbatim, attribute, ...)
2. Modules have their own parser that handles parsing `RM_Call` replies and translates
them to RedisModuleCallReply objects. The parser does not support resp3.
In addition, in the future, we want to add Redis Function (#8693) that will probably
support more languages. At some point maintaining so many parsers will stop
scaling (bug fixes and protocol changes will need to be applied on all of them).
We will probably end up with different parsers that support different parts of the
resp protocol (like we already have today with Lua and modules)
## PR Changes
This PR attempt to unified the reply parsing of Lua and modules (and in the future
Redis Function) by introducing a new parser unit (`resp_parser.c`). The new parser
handles parsing the reply and calls different callbacks to allow the users (another
unit that uses the parser, i.e, Lua, modules, or Redis Function) to analyze the reply.
### Lua API Additions
The code that handles reply parsing on `scripting.c` was removed. Instead, it uses
the resp_parser to parse and create a Lua object out of the reply. As mentioned
above the Lua parser did not handle parsing big numbers, verbatim, and attribute.
The new parser can handle those and so Lua also gets it for free.
Those are translated to Lua objects in the following way:
1. Big Number - Lua table `{'big_number':'<str representation for big number>'}`
2. Verbatim - Lua table `{'verbatim_string':{'format':'<verbatim format>', 'string':'<verbatim string value>'}}`
3. Attribute - currently ignored and not expose to the Lua parser, another issue will be open to decide how to expose it.
Tests were added to check resp3 reply parsing on Lua
### Modules API Additions
The reply parsing code on `module.c` was also removed and the new resp_parser is used instead.
In addition, the RedisModuleCallReply was also extracted to a separate unit located on `call_reply.c`
(in the future, this unit will also be used by Redis Function). A nice side effect of unified parsing is
that modules now also support resp3. Resp3 can be enabled by giving `3` as a parameter to the
fmt argument of `RM_Call`. It is also possible to give `0`, which will indicate an auto mode. i.e, Redis
will automatically chose the reply protocol base on the current client set on the RedisModuleCtx
(this mode will mostly be used when the module want to pass the reply to the client as is).
In addition, the following RedisModuleAPI were added to allow analyzing resp3 replies:
* New RedisModuleCallReply types:
* `REDISMODULE_REPLY_MAP`
* `REDISMODULE_REPLY_SET`
* `REDISMODULE_REPLY_BOOL`
* `REDISMODULE_REPLY_DOUBLE`
* `REDISMODULE_REPLY_BIG_NUMBER`
* `REDISMODULE_REPLY_VERBATIM_STRING`
* `REDISMODULE_REPLY_ATTRIBUTE`
* New RedisModuleAPI:
* `RedisModule_CallReplyDouble` - getting double value from resp3 double reply
* `RedisModule_CallReplyBool` - getting boolean value from resp3 boolean reply
* `RedisModule_CallReplyBigNumber` - getting big number value from resp3 big number reply
* `RedisModule_CallReplyVerbatim` - getting format and value from resp3 verbatim reply
* `RedisModule_CallReplySetElement` - getting element from resp3 set reply
* `RedisModule_CallReplyMapElement` - getting key and value from resp3 map reply
* `RedisModule_CallReplyAttribute` - getting a reply attribute
* `RedisModule_CallReplyAttributeElement` - getting key and value from resp3 attribute reply
* New context flags:
* `REDISMODULE_CTX_FLAGS_RESP3` - indicate that the client is using resp3
Tests were added to check the new RedisModuleAPI
### Modules API Changes
* RM_ReplyWithCallReply might return REDISMODULE_ERR if the given CallReply is in resp3
but the client expects resp2. This is not a breaking change because in order to get a resp3
CallReply one needs to specifically specify `3` as a parameter to the fmt argument of
`RM_Call` (as mentioned above).
Tests were added to check this change
### More small Additions
* Added `debug set-disable-deny-scripts` that allows to turn on and off the commands no-script
flag protection. This is used by the Lua resp3 tests so it will be possible to run `debug protocol`
and check the resp3 parsing code.
Co-authored-by: Oran Agra <oran@redislabs.com>
Co-authored-by: Yossi Gottlieb <yossigo@gmail.com>
fixes test issue introduced in #9167
1. invalid reads due to accessing non-retained string (passed as unblock context).
2. leaking module blocked client context, see #6922 for info.
Modules that use background threads with thread safe contexts are likely
to use RM_BlockClient() without a timeout function, because they do not
set up a timeout.
Before this commit, `CLIENT UNBLOCK` would result with a crash as the
`NULL` timeout callback is called. Beyond just crashing, this is also
logically wrong as it may throw the module into an unexpected client
state.
This commits makes `CLIENT UNBLOCK` on such clients behave the same as
any other client that is not in a blocked state and therefore cannot be
unblocked.
- Introduce a new sdssubstr api as a building block for sdsrange.
The API of sdsrange is many times hard to work with and also has
corner case that cause bugs. sdsrange is easy to work with and also
simplifies the implementation of sdsrange.
- Revert the fix to RM_StringTruncate and just use sdssubstr instead of
sdsrange.
- Solve valgrind warnings from the new tests introduced by the previous
PR.
Previously, passing 0 for newlen would not truncate the string at all.
This adds handling of this case, freeing the old string and creating a new empty string.
Other changes:
- Move `src/modules/testmodule.c` to `tests/modules/basics.c`
- Introduce that basic test into the test suite
- Add tests to cover StringTruncate
- Add `test-modules` build target for the main makefile
- Extend `distclean` build target to clean modules too
Create new module type enhanced callbacks: mem_usage2, free_effort2, unlink2, copy2.
These will be given a context point from which the module can obtain the key name and database id.
In addition the digest and defrag context can now be used to obtain the key name and database id.
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`
Adding a new type mask for key space notification, REDISMODULE_NOTIFY_MODULE, to enable unique notifications from commands on REDISMODULE_KEYTYPE_MODULE type keys (which is currently unsupported).
Modules can subscribe to a module key keyspace notification by RM_SubscribeToKeyspaceEvents,
and clients by notify-keyspace-events of redis.conf or via the CONFIG SET, with the characters 'd' or 'A'
(REDISMODULE_NOTIFY_MODULE type mask is part of the '**A**ll' notation for key space notifications).
Refactor: move some pubsub test infra from pubsub.tcl to util.tcl to be re-used by other tests.
