1. 20 Jan, 2022 1 commit
    • perryitay's avatar
      Adding module api for processing commands during busy jobs and allow flagging... · c4b78823
      perryitay authored
      
      Adding module api for processing commands during busy jobs and allow flagging the commands that should be handled at this status (#9963)
      
      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: default avatarOran Agra <oran@redislabs.com>
      c4b78823
  2. 18 Jan, 2022 1 commit
    • Yossi Gottlieb's avatar
      Fix additional AOF filename issues. (#10110) · 25e6d4d4
      Yossi Gottlieb authored
      This extends the previous fix (#10049) to address any form of
      non-printable or whitespace character (including newlines, quotes,
      non-printables, etc.)
      
      Also, removes the limitation on appenddirname, to align with the way
      filenames are handled elsewhere in Redis.
      25e6d4d4
  3. 17 Jan, 2022 1 commit
    • Oran Agra's avatar
      Set repl-diskless-sync to yes by default, add repl-diskless-sync-max-replicas (#10092) · ae899589
      Oran Agra authored
      1. enable diskless replication by default
      2. add a new config named repl-diskless-sync-max-replicas that enables
         replication to start before the full repl-diskless-sync-delay was
         reached.
      3. put replica online sooner on the master (see below)
      4. test suite uses repl-diskless-sync-delay of 0 to be faster
      5. a few tests that use multiple replica on a pre-populated master, are
         now using the new repl-diskless-sync-max-replicas
      6. fix possible timing issues in a few cluster tests (see below)
      
      put replica online sooner on the master 
      ----------------------------------------------------
      there were two tests that failed because they needed for the master to
      realize that the replica is online, but the test code was actually only
      waiting for the replica to realize it's online, and in diskless it could
      have been before the master realized it.
      
      changes include two things:
      1. the tests wait on the right thing
      2. issues in the master, putting the replica online in two steps.
      
      the master used to put the replica as online in 2 steps. the first
      step was to mark it as online, and the second step was to enable the
      write event (only after getting ACK), but in fact the first step didn't
      contains some of the tasks to put it online (like updating good slave
      count, and sending the module event). this meant that if a test was
      waiting to see that the replica is online form the point of view of the
      master, and then confirm that the module got an event, or that the
      master has enough good replicas, it could fail due to timing issues.
      
      so now the full effect of putting the replica online, happens at once,
      and only the part about enabling the writes is delayed till the ACK.
      
      fix cluster tests 
      --------------------
      I added some code to wait for the replica to sync and avoid race
      conditions.
      later realized the sentinel and cluster tests where using the original 5
      seconds delay, so changed it to 0.
      
      this means the other changes are probably not needed, but i suppose
      they're still better (avoid race conditions)
      ae899589
  4. 10 Jan, 2022 2 commits
  5. 05 Jan, 2022 1 commit
    • filipe oliveira's avatar
      Added INFO LATENCYSTATS section: latency by percentile distribution/latency by... · 5dd15443
      filipe oliveira authored
      
      Added INFO LATENCYSTATS section: latency by percentile distribution/latency by cumulative distribution of latencies (#9462)
      
      # Short description
      
      The Redis extended latency stats track per command latencies and enables:
      - exporting the per-command percentile distribution via the `INFO LATENCYSTATS` command.
        **( percentile distribution is not mergeable between cluster nodes ).**
      - exporting the per-command cumulative latency distributions via the `LATENCY HISTOGRAM` command.
        Using the cumulative distribution of latencies we can merge several stats from different cluster nodes
        to calculate aggregate metrics .
      
      By default, the extended latency monitoring is enabled since the overhead of keeping track of the
      command latency is very small.
       
      If you don't want to track extended latency metrics, you can easily disable it at runtime using the command:
       - `CONFIG SET latency-tracking no`
      
      By default, the exported latency percentiles are the p50, p99, and p999.
      You can alter them at runtime using the command:
      - `CONFIG SET latency-tracking-info-percentiles "0.0 50.0 100.0"`
      
      
      ## Some details:
      - The total size per histogram should sit around 40 KiB. We only allocate those 40KiB when a command
        was called for the first time.
      - With regards to the WRITE overhead As seen below, there is no measurable overhead on the achievable
        ops/sec or full latency spectrum on the client. Including also the measured redis-benchmark for unstable
        vs this branch. 
      - We track from 1 nanosecond to 1 second ( everything above 1 second is considered +Inf )
      
      ## `INFO LATENCYSTATS` exposition format
      
         - Format: `latency_percentiles_usec_<CMDNAME>:p0=XX,p50....` 
      
      ## `LATENCY HISTOGRAM [command ...]` exposition format
      
      Return a cumulative distribution of latencies in the format of a histogram for the specified command names.
      
      The histogram is composed of a map of time buckets:
      - Each representing a latency range, between 1 nanosecond and roughly 1 second.
      - Each bucket covers twice the previous bucket's range.
      - Empty buckets are not printed.
      - Everything above 1 sec is considered +Inf.
      - At max there will be log2(1000000000)=30 buckets
      
      We reply a map for each command in the format:
      `<command name> : { `calls`: <total command calls> , `histogram` : { <bucket 1> : latency , < bucket 2> : latency, ...  } }`
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      5dd15443
  6. 04 Jan, 2022 1 commit
    • zhaozhao.zz's avatar
      use startEvictionTimeProc() in config set maxmemory (#10019) · 2e1979a2
      zhaozhao.zz authored
      This would mean that the effects of `CONFIG SET maxmemory` may not be visible once the command returns.
      That could anyway happen since incremental eviction was added in redis 6.2 (see #7653)
      
      We do this to fix one of the propagation bugs about eviction see #9890 and #10014.
      2e1979a2
  7. 03 Jan, 2022 3 commits
    • chenyang8094's avatar
      Implement Multi Part AOF mechanism to avoid AOFRW overheads. (#9788) · 87789fae
      chenyang8094 authored
      
      
      Implement Multi-Part AOF mechanism to avoid overheads during AOFRW.
      Introducing a folder with multiple AOF files tracked by a manifest file.
      
      The main issues with the the original AOFRW mechanism are:
      * buffering of commands that are processed during rewrite (consuming a lot of RAM)
      * freezes of the main process when the AOFRW completes to drain the remaining part of the buffer and fsync it.
      * double disk IO for the data that arrives during AOFRW (had to be written to both the old and new AOF files)
      
      The main modifications of this PR:
      1. Remove the AOF rewrite buffer and related code.
      2. Divide the AOF into multiple files, they are classified as two types, one is the the `BASE` type,
        it represents the full amount of data (Maybe AOF or RDB format) after each AOFRW, there is only
        one `BASE` file at most. The second is `INCR` type, may have more than one. They represent the
        incremental commands since the last AOFRW.
      3. Use a AOF manifest file to record and manage these AOF files mentioned above.
      4. The original configuration of `appendfilename` will be the base part of the new file name, for example:
        `appendonly.aof.1.base.rdb` and `appendonly.aof.2.incr.aof`
      5. Add manifest-related TCL tests, and modified some existing tests that depend on the `appendfilename`
      6. Remove the `aof_rewrite_buffer_length` field in info.
      7. Add `aof-disable-auto-gc` configuration. By default we're automatically deleting HISTORY type AOFs.
        It also gives users the opportunity to preserve the history AOFs. just for testing use now.
      8. Add AOFRW limiting measure. When the AOFRW failures reaches the threshold (3 times now),
        we will delay the execution of the next AOFRW by 1 minute. If the next AOFRW also fails, it will be
        delayed by 2 minutes. The next is 4, 8, 16, the maximum delay is 60 minutes (1 hour). During the limit
        period, we can still use the 'bgrewriteaof' command to execute AOFRW immediately.
      9. Support upgrade (load) data from old version redis.
      10. Add `appenddirname` configuration, as the directory name of the append only files. All AOF files and
        manifest file will be placed in this directory.
      11. Only the last AOF file (BASE or INCR) can be truncated. Otherwise redis will exit even if
        `aof-load-truncated` is enabled.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      87789fae
    • Madelyn Olson's avatar
      Implement clusterbus message extensions and cluster hostname support (#9530) · 5460c100
      Madelyn Olson authored
      Implement the ability for cluster nodes to advertise their location with extension messages.
      5460c100
    • Harkrishn Patro's avatar
      Sharded pubsub implementation (#8621) · 9f888576
      Harkrishn Patro authored
      
      
      This commit implements a sharded pubsub implementation based off of shard channels.
      Co-authored-by: default avatarHarkrishn Patro <harkrisp@amazon.com>
      Co-authored-by: default avatarMadelyn Olson <madelyneolson@gmail.com>
      9f888576
  8. 02 Jan, 2022 1 commit
    • Viktor Söderqvist's avatar
      Wait for replicas when shutting down (#9872) · 45a155bd
      Viktor Söderqvist authored
      
      
      To avoid data loss, this commit adds a grace period for lagging replicas to
      catch up the replication offset.
      
      Done:
      
      * Wait for replicas when shutdown is triggered by SIGTERM and SIGINT.
      
      * Wait for replicas when shutdown is triggered by the SHUTDOWN command. A new
        blocked client type BLOCKED_SHUTDOWN is introduced, allowing multiple clients
        to call SHUTDOWN in parallel.
        Note that they don't expect a response unless an error happens and shutdown is aborted.
      
      * Log warning for each replica lagging behind when finishing shutdown.
      
      * CLIENT_PAUSE_WRITE while waiting for replicas.
      
      * Configurable grace period 'shutdown-timeout' in seconds (default 10).
      
      * New flags for the SHUTDOWN command:
      
          - NOW disables the grace period for lagging replicas.
      
          - FORCE ignores errors writing the RDB or AOF files which would normally
            prevent a shutdown.
      
          - ABORT cancels ongoing shutdown. Can't be combined with other flags.
      
      * New field in the output of the INFO command: 'shutdown_in_milliseconds'. The
        value is the remaining maximum time to wait for lagging replicas before
        finishing the shutdown. This field is present in the Server section **only**
        during shutdown.
      
      Not directly related:
      
      * When shutting down, if there is an AOF saving child, it is killed **even** if AOF
        is disabled. This can happen if BGREWRITEAOF is used when AOF is off.
      
      * Client pause now has end time and type (WRITE or ALL) per purpose. The
        different pause purposes are *CLIENT PAUSE command*, *failover* and
        *shutdown*. If clients are unpaused for one purpose, it doesn't affect client
        pause for other purposes. For example, the CLIENT UNPAUSE command doesn't
        affect client pause initiated by the failover or shutdown procedures. A completed
        failover or a failed shutdown doesn't unpause clients paused by the CLIENT
        PAUSE command.
      
      Notes:
      
      * DEBUG RESTART doesn't wait for replicas.
      
      * We already have a warning logged when a replica disconnects. This means that
        if any replica connection is lost during the shutdown, it is either logged as
        disconnected or as lagging at the time of exit.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      45a155bd
  9. 28 Dec, 2021 1 commit
    • guybe7's avatar
      Remove incomplete fix of a broader problem (#10013) · 266d9506
      guybe7 authored
      Preventing COFIG SET maxmemory from propagating is just the tip of the iceberg.
      Module that performs a write operation in a notification can cause any
      command to be propagated, based on server.dirty
      
      We need to come up with a better solution.
      266d9506
  10. 22 Dec, 2021 2 commits
    • guybe7's avatar
      Sort out mess around propagation and MULTI/EXEC (#9890) · 7ac21307
      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)
      7ac21307
    • Oran Agra's avatar
      Allow most CONFIG SET during loading, block some commands in async-loading (#9878) · 41e6e05d
      Oran Agra authored
      ## background
      Till now CONFIG SET was blocked during loading.
      (In the not so distant past, GET was disallowed too)
      
      We recently (not released yet) added an async-loading mode, see #9323,
      and during that time it'll serve CONFIG SET and any other command.
      And now we realized (#9770) that some configs, and commands are dangerous
      during async-loading.
      
      ## changes
      * Allow most CONFIG SET during loading (both on async-loading and normal loading)
      * Allow CONFIG REWRITE and CONFIG RESETSTAT during loading
      * Block a few config during loading (`appendonly`, `repl-diskless-load`, and `dir`)
      * Block a few commands during loading (list below)
      
      ## the blocked commands:
      * SAVE - obviously we don't wanna start a foregreound save during loading 8-)
      * BGSAVE - we don't mind to schedule one, but we don't wanna fork now
      * BGREWRITEAOF - we don't mind to schedule one, but we don't wanna fork now
      * MODULE - we obviously don't wanna unload a module during replication / rdb loading
        (MODULE HELP and MODULE LIST are not blocked)
      * SYNC / PSYNC - we're in the middle of RDB loading from master, must not allow sync
        requests now.
      * REPLICAOF / SLAVEOF - we're in the middle of replicating, maybe it makes sense to let
        the user abort it, but he couldn't do that so far, i don't wanna take any risk of bugs due to odd state.
      * CLUSTER - only allow [HELP, SLOTS, NODES, INFO, MYID, LINKS, KEYSLOT, COUNTKEYSINSLOT,
        GETKEYSINSLOT, RESET, REPLICAS, COUNT_FAILURE_REPORTS], for others, preserve the status quo
      
      ## other fixes
      * processEventsWhileBlocked had an issue when being nested, this could happen with a busy script
        during async loading (new), but also in a busy script during AOF loading (old). this lead to a crash in
        the scenario described in #6988
      41e6e05d
  11. 21 Dec, 2021 1 commit
    • zhugezy's avatar
      Remove EVAL script verbatim replication, propagation, and deterministic execution logic (#9812) · 1b0968df
      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: default avatarOran Agra <oran@redislabs.com>
      1b0968df
  12. 19 Dec, 2021 1 commit
    • YaacovHazan's avatar
      Protected configs and sensitive commands (#9920) · ae2f5b7b
      YaacovHazan authored
      Block sensitive configs and commands by default.
      
      * `enable-protected-configs` - block modification of configs with the new `PROTECTED_CONFIG` flag.
         Currently we add this flag to `dbfilename`, and `dir` configs,
         all of which are non-mutable configs that can set a file redis will write to.
      * `enable-debug-command` - block the `DEBUG` command
      * `enable-module-command` - block the `MODULE` command
      
      These have a default value set to `no`, so that these features are not
      exposed by default to client connections, and can only be set by modifying the config file.
      
      Users can change each of these to either `yes` (allow all access), or `local` (allow access from
      local TCP connections and unix domain connections)
      
      Note that this is a **breaking change** (specifically the part about MODULE command being disabled by default).
      I.e. we don't consider DEBUG command being blocked as an issue (people shouldn't have been using it),
      and the few configs we protected are unlikely to have been set at runtime anyway.
      On the other hand, it's likely to assume some users who use modules, load them from the config file anyway.
      Note that's the whole point of this PR, for redis to be more secure by default and reduce the attack surface on
      innocent users, so secure defaults will necessarily mean a breaking change.
      ae2f5b7b
  13. 17 Dec, 2021 1 commit
    • ny0312's avatar
      Introduce memory management on cluster link buffers (#9774) · 792afb44
      ny0312 authored
      Introduce memory management on cluster link buffers:
       * Introduce a new `cluster-link-sendbuf-limit` config that caps memory usage of cluster bus link send buffers.
       * Introduce a new `CLUSTER LINKS` command that displays current TCP links to/from peers.
       * Introduce a new `mem_cluster_links` field under `INFO` command output, which displays the overall memory usage by all current cluster links.
       * Introduce a new `total_cluster_links_buffer_limit_exceeded` field under `CLUSTER INFO` command output, which displays the accumulated count of cluster links freed due to `cluster-link-sendbuf-limit`.
      792afb44
  14. 16 Dec, 2021 1 commit
    • yoav-steinberg's avatar
      Multiparam config get. (#9914) · 70ff26b4
      yoav-steinberg authored
      Support doing `CONFIG GET <x> <y> <z>`, each of them can also be
      a pattern with wildcards.
      
      This avoids duplicates in the result by looping over the configs and for
      each once checking all the patterns, once a match is found for a pattern
      we move on to the next config.
      70ff26b4
  15. 15 Dec, 2021 1 commit
    • Wen Hui's avatar
      Error message improvement for CONFIG SET command (#9924) · a09bc504
      Wen Hui authored
      When CONFIG SET fails, print the name of the config that failed.
      This is helpful since config set is now variadic.
      
      however, there are cases where several configs have the same apply
      function, and we can't be sure which one of them caused the failure.
      a09bc504
  16. 09 Dec, 2021 1 commit
  17. 08 Dec, 2021 1 commit
    • yoav-steinberg's avatar
      Hide hidden configs from `config get` patterns. (#9888) · 07b13260
      yoav-steinberg authored
      Added `HIDDEN_CONFIG` to hide debug / dev / testing configs from CONFIG GET
      when it is used with a wildcard.
      These are not documented in redis.conf so now CONFIG GET only works when they
      are explicitly specified.
      
      The current configs are: 
      ```
      key-load-delay
      loading-process-events-interval-bytes
      rdb-key-save-delay
      use-exit-on-panic
      watchdog-period
      ```
      07b13260
  18. 07 Dec, 2021 1 commit
    • yoav-steinberg's avatar
      Don't write oom score adj to proc unless we're managing it. (#9904) · 1736fa4d
      yoav-steinberg authored
      When disabling redis oom-score-adj managment we restore the
      base value read before enabling oom-score-adj management.
      
      This fixes an issue introduced in #9748 where updating
      `oom-score-adj-values` while `oom-score-adj` was set to `no`
      would write the base oom score adj value read on startup to `/proc`.
      This is a bug since while `oom-score-adj` is disabled we should
      never write to proc and let external processes manage it.
      
      Added appropriate tests.
      1736fa4d
  19. 01 Dec, 2021 2 commits
    • meir@redislabs.com's avatar
      Redis Functions - Move Lua related variable into luaCtx struct · e0cd580a
      meir@redislabs.com authored
      The following variable was renamed:
      1. lua_caller 			-> script_caller
      2. lua_time_limit 		-> script_time_limit
      3. lua_timedout 		-> script_timedout
      4. lua_oom 			-> script_oom
      5. lua_disable_deny_script 	-> script_disable_deny_script
      6. in_eval			-> in_script
      
      The following variables was moved to lctx under eval.c
      1.  lua
      2.  lua_client
      3.  lua_cur_script
      4.  lua_scripts
      5.  lua_scripts_mem
      6.  lua_replicate_commands
      7.  lua_write_dirty
      8.  lua_random_dirty
      9.  lua_multi_emitted
      10. lua_repl
      11. lua_kill
      12. lua_time_start
      13. lua_time_snapshot
      
      This commit is in a low risk of introducing any issues and it
      is just moving varibales around and not changing any logic.
      e0cd580a
    • yoav-steinberg's avatar
      Multiparam config set (#9748) · 0e5b813e
      yoav-steinberg authored
      We can now do: `config set maxmemory 10m repl-backlog-size 5m`
      
      ## Basic algorithm to support "transaction like" config sets:
      
      1. Backup all relevant current values (via get).
      2. Run "verify" and "set" on everything, if we fail run "restore".
      3. Run "apply" on everything (optional optimization: skip functions already run). If we fail run "restore".
      4. Return success.
      
      ### restore
      1. Run set on everything in backup. If we fail log it and continue (this puts us in an undefined
         state but we decided it's better than the alternative of panicking). This indicates either a bug
         or some unsupported external state.
      2. Run apply on everything in backup (optimization: skip functions already run). If we fail log
         it (see comment above).
      3. Return error.
      
      ## Implementation/design changes:
      * Apply function are idempotent (have no effect if they are run more than once for the same config).
      * No indication in set functions if we're reading the config or running from the `CONFIG SET` command
         (removed `update` argument).
      * Set function should set some config variable and assume an (optional) apply function will use that
         later to apply. If we know this setting can be safely applied immediately and can always be reverted
         and doesn't depend on any other configuration we can apply immediately from within the set function
         (and not store the setting anywhere). This is the case of this `dir` config, for example, which has no
         apply function. No apply function is need also in the case that setting the variable in the `server` struct
         is all that needs to be done to make the configuration take effect. Note that the original concept of `update_fn`,
         which received the old and new values was removed and replaced by the optional apply function.
      * Apply functions use settings written to the `server` struct and don't receive any inputs.
      * I take care that for the generic (non-special) configs if there's no change I avoid calling the setter (possible
         optimization: avoid calling the apply function as well).
      * Passing the same config parameter more than once to `config set` will fail. You can't do `config set my-setting
         value1 my-setting value2`.
      
      Note that getting `save` in the context of the conf file parsing to work here as before was a pain.
      The conf file supports an aggregate `save` definition, where each `save` line is added to the server's
      save params. This is unlike any other line in the config file where each line overwrites any previous
      configuration. Since we now support passing multiple save params in a single line (see top comments
      about `save` in https://github.com/redis/redis/pull/9644) we should deprecate the aggregate nature of
      this config line and perhaps reduce this ugly code in the future.
      0e5b813e
  20. 24 Nov, 2021 1 commit
    • sundb's avatar
      Replace ziplist with listpack in quicklist (#9740) · 45129059
      sundb authored
      
      
      Part three of implementing #8702, following #8887 and #9366 .
      
      ## Description of the feature
      1. Replace the ziplist container of quicklist with listpack.
      2. Convert existing quicklist ziplists on RDB loading time. an O(n) operation.
      
      ## Interface changes
      1. New `list-max-listpack-size` config is an alias for `list-max-ziplist-size`.
      2. Replace `debug ziplist` command with `debug listpack`.
      
      ## Internal changes
      1. Add `lpMerge` to merge two listpacks . (same as `ziplistMerge`)
      2. Add `lpRepr` to print info of listpack which is used in debugCommand and `quicklistRepr`. (same as `ziplistRepr`)
      3. Replace `QUICKLIST_NODE_CONTAINER_ZIPLIST` with `QUICKLIST_NODE_CONTAINER_PACKED`(following #9357 ).
          It represent that a quicklistNode is a packed node, as opposed to a plain node.
      4. Remove `createZiplistObject` method, which is never used.
      5. Calculate listpack entry size using overhead overestimation in `quicklistAllowInsert`.
          We prefer an overestimation, which would at worse lead to a few bytes below the lowest limit of 4k.
      
      ## Improvements
      1. Calling `lpShrinkToFit` after converting Ziplist to listpack, which was missed at #9366.
      2. Optimize `quicklistAppendPlainNode` to avoid memcpy data.
      
      ## Bugfix
      1. Fix crash in `quicklistRepr` when ziplist is compressed, introduced from #9366.
      
      ## Test
      1. Add unittest for `lpMerge`.
      2. Modify the old quicklist ziplist corrupt dump test.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      45129059
  21. 11 Nov, 2021 1 commit
    • Ozan Tezcan's avatar
      Add sanitizer support and clean up sanitizer findings (#9601) · b91d8b28
      Ozan Tezcan authored
      - Added sanitizer support. `address`, `undefined` and `thread` sanitizers are available.  
      - To build Redis with desired sanitizer : `make SANITIZER=undefined`
      - There were some sanitizer findings, cleaned up codebase
      - Added tests with address and undefined behavior sanitizers to daily CI.
      - Added tests with address sanitizer to the per-PR CI (smoke out mem leaks sooner).
      
      Basically, there are three types of issues : 
      
      **1- Unaligned load/store** : Most probably, this issue may cause a crash on a platform that
      does not support unaligned access. Redis does unaligned access only on supported platforms.
      
      **2- Signed integer overflow.** Although, signed overflow issue can be problematic time to time
      and change how compiler generates code, current findings mostly about signed shift or simple
      addition overflow. For most platforms Redis can be compiled for, this wouldn't cause any issue
      as far as I can tell (checked generated code on godbolt.org).
      
       **3 -Minor leak** (redis-cli), **use-after-free**(just before calling exit());
      
      UB means nothing guaranteed and risky to reason about program behavior but I don't think any
      of the fixes here worth backporting. As sanitizers are now part of the CI, preventing new issues
      will be the real benefit. 
      b91d8b28
  22. 09 Nov, 2021 1 commit
  23. 08 Nov, 2021 1 commit
  24. 07 Nov, 2021 1 commit
    • yoav-steinberg's avatar
      Refactor config.c for generic setter interface (#9644) · 79ac5756
      yoav-steinberg authored
      
      
      This refactors all `CONFIG SET`s and conf file loading arguments go through
      the generic config handling interface.
      
      Refactoring changes:
      - All config params go through the `standardConfig` interface (some stuff which
        is only related to the config file and not the `CONFIG` command still has special
        handling for rewrite/config file parsing, `loadmodule`, for example.) .
      - Added `MULTI_ARG_CONFIG` flag for configs to signify they receive a variable
        number of arguments instead of a single argument. This is used to break up space
        separated arguments to `CONFIG SET` so the generic setter interface can pass
        multiple arguments to the setter function. When parsing the config file we also break
        up anything after the config name into multiple arguments to the setter function.
      
      Interface changes:
      - A side effect of the above interface is that the `bind` argument in the config file can
        be empty (no argument at all) this is treated the same as passing an single empty
        string argument (same as `save` already used to work).
      - Support rewrite and setting `watchdog-period` from config file (was only supported
        by the CONFIG command till now).
      - Another side effect is that the `save T X` config argument now supports multiple
        Time-Changes pairs in a single line like its `CONFIG SET` counterpart. So in the
        config file you can either do:
        ```
        save 3600 1
        save 600 10
        ```
        or do
        ```
        save 3600 1 600 10
        ```
      Co-authored-by: default avatarBjorn Svensson <bjorn.a.svensson@est.tech>
      79ac5756
  25. 25 Oct, 2021 2 commits
    • Wang Yuan's avatar
      Add timestamp annotations in AOF (#9326) · 9ec3294b
      Wang Yuan authored
      Add timestamp annotation in AOF, one part of #9325.
      
      Enabled with the new `aof-timestamp-enabled` config option.
      
      Timestamp annotation format is "#TS:${timestamp}\r\n"."
      TS" is short of timestamp and this method could save extra bytes in AOF.
      
      We can use timestamp annotation for some special functions. 
      - know the executing time of commands
      - restore data to a specific point-in-time (by using redis-check-rdb to truncate the file)
      9ec3294b
    • Wang Yuan's avatar
      Replication backlog and replicas use one global shared replication buffer (#9166) · c1718f9d
      Wang Yuan authored
      ## Background
      For redis master, one replica uses one copy of replication buffer, that is a big waste of memory,
      more replicas more waste, and allocate/free memory for every reply list also cost much.
      If we set client-output-buffer-limit small and write traffic is heavy, master may disconnect with
      replicas and can't finish synchronization with replica. If we set  client-output-buffer-limit big,
      master may be OOM when there are many replicas that separately keep much memory.
      Because replication buffers of different replica client are the same, one simple idea is that
      all replicas only use one replication buffer, that will effectively save memory.
      
      Since replication backlog content is the same as replicas' output buffer, now we
      can discard replication backlog memory and use global shared replication buffer
      to implement replication backlog mechanism.
      
      ## Implementation
      I create one global "replication buffer" which contains content of replication stream.
      The structure of "replication buffer" is similar to the reply list that exists in every client.
      But the node of list is `replBufBlock`, which has `id, repl_offset, refcount` fields.
      ```c
      /* Replication buffer blocks is the list of replBufBlock.
       *
       * +--------------+       +--------------+       +--------------+
       * | refcount = 1 |  ...  | refcount = 0 |  ...  | refcount = 2 |
       * +--------------+       +--------------+       +--------------+
       *      |                                            /       \
       *      |                                           /         \
       *      |                                          /           \
       *  Repl Backlog                               Replia_A      Replia_B
       * 
       * Each replica or replication backlog increments only the refcount of the
       * 'ref_repl_buf_node' which it points to. So when replica walks to the next
       * node, it should first increase the next node's refcount, and when we trim
       * the replication buffer nodes, we remove node always from the head node which
       * refcount is 0. If the refcount of the head node is not 0, we must stop
       * trimming and never iterate the next node. */
      
      /* Similar with 'clientReplyBlock', it is used for shared buffers between
       * all replica clients and replication backlog. */
      typedef struct replBufBlock {
          int refcount;           /* Number of replicas or repl backlog using. */
          long long id;           /* The unique incremental number. */
          long long repl_offset;  /* Start replication offset of the block. */
          size_t size, used;
          char buf[];
      } replBufBlock;
      ```
      So now when we feed replication stream into replication backlog and all replicas, we only need
      to feed stream into replication buffer `feedReplicationBuffer`. In this function, we set some fields of
      replication backlog and replicas to references of the global replication buffer blocks. And we also
      need to check replicas' output buffer limit to free if exceeding `client-output-buffer-limit`, and trim
      replication backlog if exceeding `repl-backlog-size`.
      
      When sending reply to replicas, we also need to iterate replication buffer blocks and send its
      content, when totally sending one block for replica, we decrease current node count and
      increase the next current node count, and then free the block which reference is 0 from the
      head of replication buffer blocks.
      
      Since now we use linked list to manage replication backlog, it may cost much time for iterating
      all linked list nodes to find corresponding replication buffer node. So we create a rax tree to
      store some nodes  for index, but to avoid rax tree occupying too much memory, i record
      one per 64 nodes for index.
      
      Currently, to make partial resynchronization as possible as much, we always let replication
      backlog as the last reference of replication buffer blocks, backlog size may exceeds our setting
      if slow replicas that reference vast replication buffer blocks, and this method doesn't increase
      memory usage since they share replication buffer. To avoid freezing server for freeing unreferenced
      replication buffer blocks when we need to trim backlog for exceeding backlog size setting,
      we trim backlog incrementally (free 64 blocks per call now), and make it faster in
      `beforeSleep` (free 640 blocks).
      
      ### Other changes
      - `mem_total_replication_buffers`: we add this field in INFO command, it means the total
        memory of replication buffers used.
      - `mem_clients_slaves`:  now even replica is slow to replicate, and its output buffer memory
        is not 0, but it still may be 0, since replication backlog and replicas share one global replication
        buffer, only if replication buffer memory is more than the repl backlog setting size, we consider
        the excess as replicas' memory. Otherwise, we think replication buffer memory is the consumption
        of repl backlog.
      - Key eviction
        Since all replicas and replication backlog share global replication buffer, we think only the
        part of exceeding backlog size the extra separate consumption of replicas.
        Because we trim backlog incrementally in the background, backlog size may exceeds our
        setting if slow replicas that reference vast replication buffer blocks disconnect.
        To avoid massive eviction loop, we don't count the delayed freed replication backlog into
        used memory even if there are no replicas, i.e. we also regard this memory as replicas's memory.
      - `client-output-buffer-limit` check for replica clients
        It doesn't make sense to set the replica clients output buffer limit lower than the repl-backlog-size
        config (partial sync will succeed and then replica will get disconnected). Such a configuration is
        ignored (the size of repl-backlog-size will be used). This doesn't have memory consumption
        implications since the replica client will share the backlog buffers memory.
      - Drop replication backlog after loading data if needed
        We always create replication backlog if server is a master, we need it because we put DELs in
        it when loading expired keys in RDB, but if RDB doesn't have replication info or there is no rdb,
        it is not possible to support partial resynchronization, to avoid extra memory of replication backlog,
        we drop it.
      - Multi IO threads
       Since all replicas and replication backlog use global replication buffer,  if I/O threads are enabled,
        to guarantee data accessing thread safe, we must let main thread handle sending the output buffer
        to all replicas. But before, other IO threads could handle sending output buffer of all replicas.
      
      ## Other optimizations
      This solution resolve some other problem:
      - When replicas disconnect with master since of out of output buffer limit, releasing the output
        buffer of replicas may freeze server if we set big `client-output-buffer-limit` for replicas, but now,
        it doesn't cause freezing.
      - This implementation may mitigate reply list copy cost time(also freezes server) when one replication
        has huge reply buffer and another replica can copy buffer for full synchronization. now, we just copy
        reference info, it is very light.
      - If we set replication backlog size big, it also may cost much time to copy replication backlog into
        replica's output buffer. But this commit eliminates this problem.
      - Resizing replication backlog size doesn't empty current replication backlog content.
      c1718f9d
  26. 20 Oct, 2021 1 commit
    • guybe7's avatar
      Treat subcommands as commands (#9504) · 43e736f7
      guybe7 authored
      ## 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)
      43e736f7
  27. 19 Oct, 2021 2 commits
  28. 13 Oct, 2021 1 commit
  29. 08 Oct, 2021 2 commits
  30. 23 Sep, 2021 1 commit
    • yoav-steinberg's avatar
      Client eviction (#8687) · 2753429c
      yoav-steinberg authored
      
      
      ### 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: default avatarOran Agra <oran@redislabs.com>
      2753429c
  31. 09 Sep, 2021 1 commit
    • sundb's avatar
      Replace all usage of ziplist with listpack for t_zset (#9366) · 3ca6972e
      sundb authored
      Part two of implementing #8702 (zset), after #8887.
      
      ## Description of the feature
      Replaced all uses of ziplist with listpack in t_zset, and optimized some of the code to optimize performance.
      
      ## Rdb format changes
      New `RDB_TYPE_ZSET_LISTPACK` rdb type.
      
      ## Rdb loading improvements:
      1) Pre-expansion of dict for validation of duplicate data for listpack and ziplist.
      2) Simplifying the release of empty key objects when RDB loading.
      3) Unify ziplist and listpack data verify methods for zset and hash, and move code to rdb.c.
      
      ## Interface changes
      1) New `zset-max-listpack-entries` config is an alias for `zset-max-ziplist-entries` (same with `zset-max-listpack-value`).
      2) OBJECT ENCODING will return listpack instead of ziplist.
      
      ## Listpack improvements:
      1) Add `lpDeleteRange` and `lpDeleteRangeWithEntry` functions to delete a range of entries from listpack.
      2) Improve the performance of `lpCompare`, converting from string to integer is faster than converting from integer to string.
      3) Replace `snprintf` with `ll2string` to improve performance in converting numbers to strings in `lpGet()`.
      
      ## Zset improvements:
      1) Improve the performance of `zzlFind` method, use `lpFind` instead of `lpCompare` in a loop.
      2) Use `lpDeleteRangeWithEntry` instead of `lpDelete` twice to delete a element of zset.
      
      ## Tests
      1) Add some unittests for `lpDeleteRange` and `lpDeleteRangeWithEntry` function.
      2) Add zset RDB loading test.
      3) Add benchmark test for `lpCompare` and `ziplsitCompare`.
      4) Add empty listpack zset corrupt dump test.
      3ca6972e
  32. 29 Aug, 2021 1 commit