- 14 Jan, 2022 1 commit
-
-
Meir Shpilraien (Spielrein) authored
# Redis Functions Flags Following the discussion on #10025 Added Functions Flags support. The PR is divided to 2 sections: * Add named argument support to `redis.register_function` API. * Add support for function flags ## `redis.register_function` named argument support The first part of the PR adds support for named argument on `redis.register_function`, example: ``` redis.register_function{ function_name='f1', callback=function() return 'hello' end, description='some desc' } ``` The positional arguments is also kept, which means that it still possible to write: ``` redis.register_function('f1', function() return 'hello' end) ``` But notice that it is no longer possible to pass the optional description argument on the positional argument version. Positional argument was change to allow passing only the mandatory arguments (function name and callback). To pass more arguments the user must use the named argument version. As with positional arguments, the `function_name` and `callback` is mandatory and an error will be raise if those are missing. Also, an error will be raise if an unknown argument name is given or the arguments type is wrong. Tests was added to verify the new syntax. ## Functions Flags The second part of the PR is adding functions flags support. Flags are given to Redis when the engine calls `functionLibCreateFunction`, supported flags are: * `no-writes` - indicating the function perform no writes which means that it is OK to run it on: * read-only replica * Using FCALL_RO * If disk error detected It will not be possible to run a function in those situations unless the function turns on the `no-writes` flag * `allow-oom` - indicate that its OK to run the function even if Redis is in OOM state, if the function will not turn on this flag it will not be possible to run it if OOM reached (even if the function declares `no-writes` and even if `fcall_ro` is used). If this flag is set, any command will be allow on OOM (even those that is marked with CMD_DENYOOM). The assumption is that this flag is for advance users that knows its meaning and understand what they are doing, and Redis trust them to not increase the memory usage. (e.g. it could be an INCR or a modification on an existing key, or a DEL command) * `allow-state` - indicate that its OK to run the function on stale replica, in this case we will also make sure the function is only perform `stale` commands and raise an error if not. * `no-cluster` - indicate to disallow running the function if cluster is enabled. Default behaviure of functions (if no flags is given): 1. Allow functions to read and write 2. Do not run functions on OOM 3. Do not run functions on stale replica 4. Allow functions on cluster ### Lua API for functions flags On Lua engine, it is possible to give functions flags as `flags` named argument: ``` redis.register_function{function_name='f1', callback=function() return 1 end, flags={'no-writes', 'allow-oom'}, description='description'} ``` The function flags argument must be a Lua table that contains all the requested flags, The following will result in an error: * Unknown flag * Wrong flag type Default behaviour is the same as if no flags are used. Tests were added to verify all flags functionality ## Additional changes * mark FCALL and FCALL_RO with CMD_STALE flag (unlike EVAL), so that they can run if the function was registered with the `allow-stale` flag. * Verify `CMD_STALE` on `scriptCall` (`redis.call`), so it will not be possible to call commands from script while stale unless the command is marked with the `CMD_STALE` flags. so that even if the function is allowed while stale we do not allow it to bypass the `CMD_STALE` flag of commands. * Flags section was added to `FUNCTION LIST` command to provide the set of flags for each function: ``` > FUNCTION list withcode 1) 1) "library_name" 2) "test" 3) "engine" 4) "LUA" 5) "description" 6) (nil) 7) "functions" 8) 1) 1) "name" 2) "f1" 3) "description" 4) (nil) 5) "flags" 6) (empty array) 9) "library_code" 10) "redis.register_function{function_name='f1', callback=function() return 1 end}" ``` * Added API to get Redis version from within a script, The redis version can be provided using: 1. `redis.REDIS_VERSION` - string representation of the redis version in the format of MAJOR.MINOR.PATH 2. `redis.REDIS_VERSION_NUM` - number representation of the redis version in the format of `0x00MMmmpp` (`MM` - major, `mm` - minor, `pp` - patch). The number version can be used to check if version is greater or less another version. The string version can be used to return to the user or print as logs. This new API is provided to eval scripts and functions, it also possible to use this API during functions loading phase.
-
- 22 Dec, 2021 1 commit
-
-
guybe7 authored
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)
-
- 21 Dec, 2021 1 commit
-
-
zhugezy authored
# Background The main goal of this PR is to remove relevant logics on Lua script verbatim replication, only keeping effects replication logic, which has been set as default since Redis 5.0. As a result, Lua in Redis 7.0 would be acting the same as Redis 6.0 with default configuration from users' point of view. There are lots of reasons to remove verbatim replication. Antirez has listed some of the benefits in Issue #5292: >1. No longer need to explain to users side effects into scripts. They can do whatever they want. >2. No need for a cache about scripts that we sent or not to the slaves. >3. No need to sort the output of certain commands inside scripts (SMEMBERS and others): this both simplifies and gains speed. >4. No need to store scripts inside the RDB file in order to startup correctly. >5. No problems about evicting keys during the script execution. When looking back at Redis 5.0, antirez and core team decided to set the config `lua-replicate-commands yes` by default instead of removing verbatim replication directly, in case some bad situations happened. 3 years later now before Redis 7.0, it's time to remove it formally. # Changes - configuration for lua-replicate-commands removed - created config file stub for backward compatibility - Replication script cache removed - this is useless under script effects replication - relevant statistics also removed - script persistence in RDB files is also removed - Propagation of SCRIPT LOAD and SCRIPT FLUSH to replica / AOF removed - Deterministic execution logic in scripts removed (i.e. don't run write commands after random ones, and sorting output of commands with random order) - the flags indicating which commands have non-deterministic results are kept as hints to clients. - `redis.replicate_commands()` & `redis.set_repl()` changed - now `redis.replicate_commands()` does nothing and return an 1 - ...and then `redis.set_repl()` can be issued before `redis.replicate_commands()` now - Relevant TCL cases adjusted - DEBUG lua-always-replicate-commands removed # Other changes - Fix a recent bug comparing CLIENT_ID_AOF to original_client->flags instead of id. (introduced in #9780) Co-authored-by:
Oran Agra <oran@redislabs.com>
-
- 02 Dec, 2021 1 commit
-
-
meir@redislabs.com authored
Redis function unit is located inside functions.c and contains Redis Function implementation: 1. FUNCTION commands: * FUNCTION CREATE * FCALL * FCALL_RO * FUNCTION DELETE * FUNCTION KILL * FUNCTION INFO 2. Register engine In addition, this commit introduce the first engine that uses the Redis Function capabilities, the Lua engine.
-
- 01 Dec, 2021 1 commit
-
-
meir@redislabs.com authored
Script unit is a new unit located on script.c. Its purpose is to provides an API for functions (and eval) to interact with Redis. Interaction includes mostly executing commands, but also functionalities like calling Redis back on long scripts or check if the script was killed. The interaction is done using a scriptRunCtx object that need to be created by the user and initialized using scriptPrepareForRun. Detailed list of functionalities expose by the unit: 1. Calling commands (including all the validation checks such as acl, cluster, read only run, ...) 2. Set Resp 3. Set Replication method (AOF/REPLICATION/NONE) 4. Call Redis back to on long running scripts to allow Redis reply to clients and perform script kill The commit introduce the new unit and uses it on eval commands to interact with Redis.
-