1. 06 Jan, 2022 1 commit
    • Meir Shpilraien (Spielrein)'s avatar
      Redis Function Libraries (#10004) · 885f6b5c
      Meir Shpilraien (Spielrein) authored
      # Redis Function Libraries
      
      This PR implements Redis Functions Libraries as describe on: https://github.com/redis/redis/issues/9906.
      
      Libraries purpose is to provide a better code sharing between functions by allowing to create multiple
      functions in a single command. Functions that were created together can safely share code between
      each other without worrying about compatibility issues and versioning.
      
      Creating a new library is done using 'FUNCTION LOAD' command (full API is described below)
      
      This PR introduces a new struct called libraryInfo, libraryInfo holds information about a library:
      * name - name of the library
      * engine - engine used to create the library
      * code - library code
      * description - library description
      * functions - the functions exposed by the library
      
      When Redis gets the `FUNCTION LOAD` command it creates a new empty libraryInfo.
      Redis passes the `CODE` to the relevant engine alongside the empty libraryInfo.
      As a result, the engine will create one or more functions by calling 'libraryCreateFunction'.
      The new funcion will be added to the newly created libraryInfo. So far Everything is happening
      locally on the libraryInfo so it is easy to abort the operation (in case of an error) by simply
      freeing the libraryInfo. After the library info is fully constructed we start the joining phase by
      which we will join the new library to the other libraries currently exist on Redis.
      The joining phase make sure there is no function collision and add the library to the
      librariesCtx (renamed from functionCtx). LibrariesCtx is used all around the code in the exact
      same way as functionCtx was used (with respect to RDB loading, replicatio, ...).
      The only difference is that apart from function dictionary (maps function name to functionInfo
      object), the librariesCtx contains also a libraries dictionary that maps library name to libraryInfo object.
      
      ## New API
      ### FUNCTION LOAD
      `FUNCTION LOAD <ENGINE> <LIBRARY NAME> [REPLACE] [DESCRIPTION <DESCRIPTION>] <CODE>`
      Create a new library with the given parameters:
      * ENGINE - REPLACE Engine name to use to create the library.
      * LIBRARY NAME - The new library name.
      * REPLACE - If the library already exists, replace it.
      * DESCRIPTION - Library description.
      * CODE - Library code.
      
      Return "OK" on success, or error on the following cases:
      * Library name already taken and REPLACE was not used
      * Name collision with another existing library (even if replace was uses)
      * Library registration failed by the engine (usually compilation error)
      
      ## Changed API
      ### FUNCTION LIST
      `FUNCTION LIST [LIBRARYNAME <LIBRARY NAME PATTERN>] [WITHCODE]`
      Command was modified to also allow getting libraries code (so `FUNCTION INFO` command is no longer
      needed and removed). In addition the command gets an option argument, `LIBRARYNAME` allows you to
      only get libraries that match the given `LIBRARYNAME` pattern. By default, it returns all libraries.
      
      ### INFO MEMORY
      Added number of libraries to `INFO MEMORY`
      
      ### Commands flags
      `DENYOOM` flag was set on `FUNCTION LOAD` and `FUNCTION RESTORE`. We consider those commands
      as commands that add new data to the dateset (functions are data) and so we want to disallows
      to run those commands on OOM.
      
      ## Removed API
      * FUNCTION CREATE - Decided on https://github.com/redis/redis/issues/9906
      * FUNCTION INFO - Decided on https://github.com/redis/redis/issues/9899
      
      ## Lua engine changes
      When the Lua engine gets the code given on `FUNCTION LOAD` command, it immediately runs it, we call
      this run the loading run. Loading run is not a usual script run, it is not possible to invoke any
      Redis command from within the load run.
      Instead there is a new API provided by `library` object. The new API's: 
      * `redis.log` - behave the same as `redis.log`
      * `redis.register_function` - register a new function to the library
      
      The loading run purpose is to register functions using the new `redis.register_function` API.
      Any attempt to use any other API will result in an error. In addition, the load run is has a time
      limit of 500ms, error is raise on timeout and the entire operation is aborted.
      
      ### `redis.register_function`
      `redis.register_function(<function_name>, <callback>, [<description>])`
      This new API allows users to register a new function that will be linked to the newly created library.
      This API can only be called during the load run (see definition above). Any attempt to use it outside
      of the load run will result in an error.
      The parameters pass to the API are:
      * function_name - Function name (must be a Lua string)
      * callback - Lua function object that will be called when the function is invokes using fcall/fcall_ro
      * description - Function description, optional (must be a Lua string).
      
      ### Example
      The following example creates a library called `lib` with 2 functions, `f1` and `f1`, returns 1 and 2 respectively:
      ```
      local function f1(keys, args)
          return 1
      end
      
      local function f2(keys, args)
          return 2
      end
      
      redis.register_function('f1', f1)
      redis.register_function('f2', f2)
      ```
      
      Notice: Unlike `eval`, functions inside a library get the KEYS and ARGV as arguments to the
      functions and not as global.
      
      ### Technical Details
      
      On the load run we only want the user to be able to call a white list on API's. This way, in
      the future, if new API's will be added, the new API's will not be available to the load run
      unless specifically added to this white list. We put the while list on the `library` object and
      make sure the `library` object is only available to the load run by using [lua_setfenv](https://www.lua.org/manual/5.1/manual.html#lua_setfenv) API. This API allows us to set
      the `globals` of a function (and all the function it creates). Before starting the load run we
      create a new fresh Lua table (call it `g`) that only contains the `library` API (we make sure
      to set global protection on this table just like the general global protection already exists
      today), then we use [lua_setfenv](https://www.lua.org/manual/5.1/manual.html#lua_setfenv)
      to set `g` as the global table of the load run. After the load run finished we update `g`
      metatable and set `__index` and `__newindex` functions to be `_G` (Lua default globals),
      we also pop out the `library` object as we do not need it anymore.
      This way, any function that was created on the load run (and will be invoke using `fcall`) will
      see the default globals as it expected to see them and will not have the `library` API anymore.
      
      An important outcome of this new approach is that now we can achieve a distinct global table
      for each library (it is not yet like that but it is very easy to achieve it now). In the future we can
      decide to remove global protection because global on different libraries will not collide or we
      can chose to give different API to different libraries base on some configuration or input.
      
      Notice that this technique was meant to prevent errors and was not meant to prevent malicious
      user from exploit it. For example, the load run can still save the `library` object on some local
      variable and then using in `fcall` context. To prevent such a malicious use, the C code also make
      sure it is running in the right context and if not raise an error.
      885f6b5c
  2. 26 Dec, 2021 2 commits
    • Meir Shpilraien (Spielrein)'s avatar
      Add FUNCTION DUMP and RESTORE. (#9938) · 365cbf46
      Meir Shpilraien (Spielrein) authored
      Follow the conclusions to support Functions in redis cluster (#9899)
      
      Added 2 new FUNCTION sub-commands:
      1. `FUNCTION DUMP` - dump a binary payload representation of all the functions.
      2. `FUNCTION RESTORE <PAYLOAD> [FLUSH|APPEND|REPLACE]` - give the binary payload extracted
         using `FUNCTION DUMP`, restore all the functions on the given payload. Restore policy can be given to
         control how to handle existing functions (default is APPEND):
         * FLUSH: delete all existing functions.
         * APPEND: appends the restored functions to the existing functions. On collision, abort.
         * REPLACE: appends the restored functions to the existing functions. On collision,
           replace the old function with the new function.
      
      Modify `redis-cli --cluster add-node` to use `FUNCTION DUMP` to get existing functions from
      one of the nodes in the cluster, and `FUNCTION RESTORE` to load the same set of functions
      to the new node. `redis-cli` will execute this step before sending the `CLUSTER MEET` command
      to the new node. If `FUNCTION DUMP` returns an error, assume the current Redis version do not
      support functions and skip `FUNCTION RESTORE`. If `FUNCTION RESTORE` fails, abort and do not send
      the `CLUSTER MEET` command. If the new node already contains functions (before the `FUNCTION RESTORE`
      is sent), abort and do not add the node to the cluster. Test was added to verify
      `redis-cli --cluster add-node` works as expected. 
      365cbf46
    • Meir Shpilraien (Spielrein)'s avatar
      Changed fuction name to be case insensitive. (#9984) · 08ff606b
      Meir Shpilraien (Spielrein) authored
      Use case insensitive string comparison for function names (like we do for commands and configs)
      In addition, add verification that the functions only use the following characters: [a-zA-Z0-9_]
      08ff606b
  3. 21 Dec, 2021 1 commit
    • Meir Shpilraien (Spielrein)'s avatar
      Change FUNCTION CREATE, DELETE and FLUSH to be WRITE commands instead of MAY_REPLICATE. (#9953) · 3bcf1084
      Meir Shpilraien (Spielrein) authored
      The issue with MAY_REPLICATE is that all automatic mechanisms to handle
      write commands will not work. This require have a special treatment for:
      * Not allow those commands to be executed on RO replica.
      * Allow those commands to be executed on RO replica from primary connection.
      * Allow those commands to be executed on the RO replica from AOF.
      
      By setting those commands as WRITE commands we are getting all those properties from Redis.
      Test was added to verify that those properties work as expected.
      
      In addition, rearrange when and where functions are flushed. Before this PR functions were
      flushed manually on `rdbLoadRio` and cleaned manually on failure. This contradicts the
      assumptions that functions are data and need to be created/deleted alongside with the
      data. A side effect of this, for example, `debug reload noflush` did not flush the data but
      did flush the functions, `debug loadaof` flush the data but not the functions.
      This PR move functions deletion into `emptyDb`. `emptyDb` (renamed to `emptyData`) will
      now accept an additional flag, `NOFUNCTIONS` which specifically indicate that we do not
      want to flush the functions (on all other cases, functions will be flushed). Used the new flag
      on FLUSHALL and FLUSHDB only! Tests were added to `debug reload` and `debug loadaof`
      to verify that functions behave the same as the data.
      
      Notice that because now functions will be deleted along side with the data we can not allow
      `CLUSTER RESET` to be called from within a function (it will cause the function to be released
      while running), this PR adds `NO_SCRIPT` flag to `CLUSTER RESET`  so it will not be possible
      to be called from within a function. The other cluster commands are allowed from within a
      function (there are use-cases that uses `GETKEYSINSLOT` to iterate over all the keys on a
      given slot). Tests was added to verify `CLUSTER RESET` is denied from within a script.
      
      Another small change on this PR is that `RDBFLAGS_ALLOW_DUP` is also applicable on functions.
      When loading functions, if this flag is set, we will replace old functions with new ones on collisions. 
      3bcf1084
  4. 19 Dec, 2021 1 commit
    • Oran Agra's avatar
      Add external test that runs without debug command (#9964) · 6add1b72
      Oran Agra authored
      - add needs:debug flag for some tests
      - disable "save" in external tests (speedup?)
      - use debug_digest proc instead of debug command directly so it can be skipped
      - use OBJECT ENCODING instead of DEBUG OBJECT to get encoding
      - add a proc for OBJECT REFCOUNT so it can be skipped
      - move a bunch of tests in latency_monitor tests to happen later so that latency monitor has some values in it
      - add missing close_replication_stream calls
      - make sure to close the temp client if DEBUG LOG fails
      6add1b72
  5. 16 Dec, 2021 1 commit
    • Meir Shpilraien (Spielrein)'s avatar
      Add FUNCTION FLUSH command to flush all functions (#9936) · 687210f1
      Meir Shpilraien (Spielrein) authored
      Added `FUNCTION FLUSH` command. The new sub-command allows delete all the functions.
      An optional `[SYNC|ASYNC]` argument can be given to control whether or not to flush the
      functions synchronously or asynchronously. if not given the default flush mode is chosen by
      `lazyfree-lazy-user-flush` configuration values.
      
      Add the missing `functions.tcl` test to the list of tests that are executed in test_helper.tcl,
      and call FUNCTION FLUSH in between servers in external mode
      687210f1
  6. 02 Dec, 2021 1 commit
    • meir@redislabs.com's avatar
      Redis Functions - Added redis function unit and Lua engine · cbd46317
      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.
      cbd46317