1. 20 Dec, 2022 1 commit
    • guybe7's avatar
      Cleanup: Get rid of server.core_propagates (#11572) · 9c7c6924
      guybe7 authored
      1. Get rid of server.core_propagates - we can just rely on module/call nesting levels
      2. Rename in_nested_call  to execution_nesting and update the comment
      3. Remove module_ctx_nesting (redundant, we can use execution_nesting)
      4. Modify postExecutionUnitOperations according to the comment (The main purpose of this PR)
      5. trackingHandlePendingKeyInvalidations: Check the nesting level inside this function
      9c7c6924
  2. 30 Nov, 2022 1 commit
    • guybe7's avatar
      Stream consumers: Re-purpose seen-time, add active-time (#11099) · 72e90695
      guybe7 authored
      1. "Fixed" the current code so that seen-time/idle actually refers to interaction
        attempts (as documented; breaking change)
      2. Added active-time/inactive to refer to successful interaction (what
        seen-time/idle used to be)
      
      At first, I tried to avoid changing the behavior of seen-time/idle but then realized
      that, in this case, the odds are the people read the docs and implemented their
      code based on the docs (which didn't match the behavior).
      For the most part, that would work fine, except that issue #9996 was found.
      
      I was working under the assumption that people relied on the docs, and for
      the most part, it could have worked well enough. so instead of fixing the docs,
      as I would usually do, I fixed the code to match the docs in this particular case.
      
      Note that, in case the consumer has never read any entries, the values
      for both "active-time" (XINFO FULL) and "inactive" (XINFO CONSUMERS) will
      be -1, meaning here that the consumer was never active.
      
      Note that seen/active time is only affected by XREADGROUP / X[AUTO]CLAIM, not
      by XPENDING, XINFO, and other "read-only" stream CG commands (always has been,
      even before this PR)
      
      Other changes:
      * Another behavioral change (arguably a bugfix) is that XREADGROUP and X[AUTO]CLAIM
        create the consumer regardless of whether it was able to perform some reading/claiming
      * RDB format change to save the `active_time`, and set it to the same value of `seen_time` in old rdb files.
      72e90695
  3. 24 Nov, 2022 1 commit
    • Meir Shpilraien (Spielrein)'s avatar
      Module API to allow writes after key space notification hooks (#11199) · abc345ad
      Meir Shpilraien (Spielrein) authored
      ### Summary of API additions
      
      * `RedisModule_AddPostNotificationJob` - new API to call inside a key space
        notification (and on more locations in the future) and allow to add a post job as describe above.
      * New module option, `REDISMODULE_OPTIONS_ALLOW_NESTED_KEYSPACE_NOTIFICATIONS`,
        allows to disable Redis protection of nested key-space notifications.
      * `RedisModule_GetModuleOptionsAll` - gets the mask of all supported module options so a module
        will be able to check if a given option is supported by the current running Redis instance.
      
      ### Background
      
      The following PR is a proposal of handling write operations inside module key space notifications.
      After a lot of discussions we came to a conclusion that module should not perform any write
      operations on key space notification.
      
      Some examples of issues that such write operation can cause are describe on the following links:
      
      * Bad replication oreder - https://github.com/redis/redis/pull/10969
      * Used after free - https://github.com/redis/redis/pull/10969#issuecomment-1223771006
      * Used after free - https://github.com/redis/redis/pull/9406#issuecomment-1221684054
      
      
      
      There are probably more issues that are yet to be discovered. The underline problem with writing
      inside key space notification is that the notification runs synchronously, this means that the notification
      code will be executed in the middle on Redis logic (commands logic, eviction, expire).
      Redis **do not assume** that the data might change while running the logic and such changes
      can crash Redis or cause unexpected behaviour.
      
      The solution is to state that modules **should not** perform any write command inside key space
      notification (we can chose whether or not we want to force it). To still cover the use-case where
      module wants to perform a write operation as a reaction to key space notifications, we introduce
      a new API , `RedisModule_AddPostNotificationJob`, that allows to register a callback that will be
      called by Redis when the following conditions hold:
      
      * It is safe to perform any write operation.
      * The job will be called atomically along side the operation that triggers it (in our case, key
        space notification).
      
      Module can use this new API to safely perform any write operation and still achieve atomicity
      between the notification and the write.
      
      Although currently the API is supported on key space notifications, the API is written in a generic
      way so that in the future we will be able to use it on other places (server events for example).
      
      ### Technical Details
      
      Whenever a module uses `RedisModule_AddPostNotificationJob` the callback is added to a list
      of callbacks (called `modulePostExecUnitJobs`) that need to be invoke after the current execution
      unit ends (whether its a command, eviction, or active expire). In order to trigger those callback
      atomically with the notification effect, we call those callbacks on `postExecutionUnitOperations`
      (which was `propagatePendingCommands` before this PR). The new function fires the post jobs
      and then calls `propagatePendingCommands`.
      
      If the callback perform more operations that triggers more key space notifications. Those keys
      space notifications might register more callbacks. Those callbacks will be added to the end
      of `modulePostExecUnitJobs` list and will be invoke atomically after the current callback ends.
      This raises a concerns of entering an infinite loops, we consider infinite loops as a logical bug
      that need to be fixed in the module, an attempt to protect against infinite loops by halting the
      execution could result in violation of the feature correctness and so **Redis will make no attempt
      to protect the module from infinite loops**
      
      In addition, currently key space notifications are not nested. Some modules might want to allow
      nesting key-space notifications. To allow that and keep backward compatibility, we introduce a
      new module option called `REDISMODULE_OPTIONS_ALLOW_NESTED_KEYSPACE_NOTIFICATIONS`.
      Setting this option will disable the Redis key-space notifications nesting protection and will
      pass this responsibility to the module.
      
      ### Redis infrastructure
      
      This PR promotes the existing `propagatePendingCommands` to an "Execution Unit" concept,
      which is called after each atomic unit of execution,
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      Co-authored-by: default avatarYossi Gottlieb <yossigo@gmail.com>
      Co-authored-by: default avatarMadelyn Olson <34459052+madolson@users.noreply.github.com>
      abc345ad
  4. 18 Oct, 2022 1 commit
    • guybe7's avatar
      Blocked module clients should be aware when a key is deleted (#11310) · b57fd010
      guybe7 authored
      The use case is a module that wants to implement a blocking command on a key that
      necessarily exists and wants to unblock the client in case the key is deleted (much like
      what we implemented for XREADGROUP in #10306)
      
      New module API:
      * RedisModule_BlockClientOnKeysWithFlags
      
      Flags:
      * REDISMODULE_BLOCK_UNBLOCK_NONE
      * REDISMODULE_BLOCK_UNBLOCK_DELETED
      
      ### Detailed description of code changes
      
      blocked.c:
      1. Both module and stream functions are called whether the key exists or not, regardless of
        its type. We do that in order to allow modules/stream to unblock the client in case the key
        is no longer present or has changed type (the behavior for streams didn't change, just code
        that moved into serveClientsBlockedOnStreamKey)
      2. Make sure afterCommand is called in serveClientsBlockedOnKeyByModule, in order to propagate
        actions from moduleTryServeClientBlockedOnKey.
      3. handleClientsBlockedOnKeys: call propagatePendingCommands directly after lookupKeyReadWithFlags
        to prevent a possible lazy-expire DEL from being mixed with any command propagated by the
        preceding functions.
      4. blockForKeys: Caller can specifiy that it wants to be awakened if key is deleted.
         Minor optimizations (use dictAddRaw).
      5. signalKeyAsReady became signalKeyAsReadyLogic which can take a boolean in case the key is deleted.
        It will only signal if there's at least one client that awaits key deletion (to save calls to
        handleClientsBlockedOnKeys).
        Minor optimizations (use dictAddRaw)
      
      db.c:
      1. scanDatabaseForDeletedStreams is now scanDatabaseForDeletedKeys and will signalKeyAsReady
        for any key that was removed from the database or changed type. It is the responsibility of the code
        in blocked.c to ignore or act on deleted/type-changed keys.
      2. Use the new signalDeletedKeyAsReady where needed
      
      blockedonkey.c + tcl:
      1. Added test of new capabilities (FSL.BPOPGT now requires the key to exist in order to work)
      b57fd010
  5. 09 Oct, 2022 1 commit
    • Binbin's avatar
      Freeze time sampling during command execution, and scripts (#10300) · 35b3fbd9
      Binbin authored
      Freeze time during execution of scripts and all other commands.
      This means that a key is either expired or not, and doesn't change
      state during a script execution. resolves #10182
      
      This PR try to add a new `commandTimeSnapshot` function.
      The function logic is extracted from `keyIsExpired`, but the related
      calls to `fixed_time_expire` and `mstime()` are removed, see below.
      
      In commands, we will avoid calling `mstime()` multiple times
      and just use the one that sampled in call. The background is,
      e.g. using `PEXPIRE 1` with valgrind sometimes result in the key
      being deleted rather than expired. The reason is that both `PEXPIRE`
      command and `checkAlreadyExpired` call `mstime()` separately.
      
      There are other more important changes in this PR:
      1. Eliminate `fixed_time_expire`, it is no longer needed. 
         When we want to sample time we should always use a time snapshot. 
         We will use `in_nested_call` instead to update the cached time in `call`.
      2. Move the call for `updateCachedTime` from `serverCron` to `afterSleep`.
          Now `commandTimeSnapshot` will always return the sample time, the
          `lookupKeyReadWithFlags` call in `getNodeByQuery` will get a outdated
          cached time (because `processCommand` is out of the `call` context).
          We put the call to `updateCachedTime` in `aftersleep`.
      3. Cache the time each time the module lock Redis.
          Call `updateCachedTime` in `moduleGILAfterLock`, affecting `RM_ThreadSafeContextLock`
          and `RM_ThreadSafeContextTryLock`
      
      Currently the commandTimeSnapshot change affects the following TTL commands:
      - SET EX / SET PX
      - EXPIRE / PEXPIRE
      - SETEX / PSETEX
      - GETEX EX / GETEX PX
      - TTL / PTTL
      - EXPIRETIME / PEXPIRETIME
      - RESTORE key TTL
      
      And other commands just use the cached mstime (including TIME).
      
      This is considered to be a breaking change since it can break a script
      that uses a loop to wait for a key to expire.
      35b3fbd9
  6. 25 Mar, 2022 1 commit
    • zhaozhao.zz's avatar
      optimize(remove) usage of client's pending_querybuf (#10413) · 78bef6e1
      zhaozhao.zz authored
      To remove `pending_querybuf`, the key point is reusing `querybuf`, it means master client's `querybuf` is not only used to parse command, but also proxy to sub-replicas.
      
      1. add a new variable `repl_applied` for master client to record how many data applied (propagated via `replicationFeedStreamFromMasterStream()`) but not trimmed in `querybuf`.
      
      2. don't sdsrange `querybuf` in `commandProcessed()`, we trim it to `repl_applied` after the whole replication pipeline processed to avoid fragmented `sdsrange`. And here are some scenarios we cannot trim to `qb_pos`:
          * we don't receive complete command from master
          * master client blocked because of client pause
          * IO threads operate read, master client flagged with CLIENT_PENDING_COMMAND
      
          In these scenarios, `qb_pos` points to the part of the current command or the beginning of next command, and the current command is not applied yet, so the `repl_applied` is not equal to `qb_pos`.
      
      Some other notes:
      * Do not do big arg optimization on master client, since we can only sdsrange `querybuf` after data sent to replicas.
      * Set `qb_pos` and `repl_applied` to 0 when `freeClient` in `replicationCacheMaster`.
      * Rewrite `processPendingCommandsAndResetClient` to `processPendingCommandAndInputBuffer`, let `processInputBuffer` to be called successively after `processCommandAndResetClient`.
      78bef6e1
  7. 20 Mar, 2022 1 commit
    • 郭伟光's avatar
      unblockClient: avoid to reset client when the client was shutdown-blocked (#10440) · fae5b1a1
      郭伟光 authored
      fix #10439. see https://github.com/redis/redis/pull/9872
      When executing SHUTDOWN we pause the client so we can un-pause it
      if the shutdown fails.
      this could happen during the timeout, if the shutdown is aborted, but could
      also happen from withing the initial `call()` to shutdown, if the rdb save fails.
      in that case when we return to `call()`, we'll crash if `c->cmd` has been set to NULL.
      
      The call stack is:
      ```
      unblockClient(c)
      replyToClientsBlockedOnShutdown()
      cancelShutdown()
      finishShutdown()
      prepareForShutdown()
      shutdownCommand()
      ```
      
      what's special about SHUTDOWN in that respect is that it can be paused,
      and then un-paused before the original `call()` returns.
      tests where added for both failed shutdown, and a followup successful one.
      fae5b1a1
  8. 08 Mar, 2022 1 commit
    • guybe7's avatar
      XREADGROUP: Unblock client if stream is deleted (#10306) · 2a295408
      guybe7 authored
      Deleting a stream while a client is blocked XREADGROUP should unblock the client.
      
      The idea is that if a client is blocked via XREADGROUP is different from
      any other blocking type in the sense that it depends on the existence of both
      the key and the group. Even if the key is deleted and then revived with XADD
      it won't help any clients blocked on XREADGROUP because the group no longer
      exist, so they would fail with -NOGROUP anyway.
      The conclusion is that it's better to unblock these clients (with error) upon
      the deletion of the key, rather than waiting for the first XADD. 
      
      Other changes:
      1. Slightly optimize all `serveClientsBlockedOn*` functions by checking `server.blocked_clients_by_type`
      2. All `serveClientsBlockedOn*` functions now use a list iterator rather than looking at `listFirst`, relying
        on `unblockClient` to delete the head of the list. Before this commit, only `serveClientsBlockedOnStreams`
        used to work like that.
      3. bugfix: CLIENT UNBLOCK ERROR should work even if the command doesn't have a timeout_callback
        (only relevant to module commands)
      2a295408
  9. 21 Feb, 2022 1 commit
    • Oran Agra's avatar
      Fix error stats and failed command stats for blocked clients (#10309) · fad0b0d2
      Oran Agra authored
      This is a followup work for #10278, and a discussion about #10279
      
      The changes:
      - fix failed_calls in command stats for blocked clients that got error.
        including CLIENT UNBLOCK, and module replying an error from a thread.
      - fix latency stats for XREADGROUP that filed with -NOGROUP
      
      Theory behind which errors should be counted:
      - error stats represents errors returned to the user, so an error handled by a
        module should not be counted.
      - total error counter should be the same.
      - command stats represents execution of commands (even with RM_Call, and if
        they fail or get rejected it counts these calls in commandstats, so it should
        also count failed_calls)
      
      Some thoughts about Scripts:
      for scripts it could be different since they're part of user code, not the infra (not an extension to redis)
      we certainly want commandstats to contain all calls and errors
      a simple script is like mult-exec transaction so an error inside it should be counted in error stats
      a script that replies with an error to the user (using redis.error_reply) should also be counted in error stats
      but then the problem is that a plain `return redis.call("SET")` should not be counted twice (once for the SET
      and once for EVAL)
      so that's something left to be resolved in #10279
      fad0b0d2
  10. 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
  11. 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
  12. 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
  13. 22 Dec, 2021 1 commit
    • 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
  14. 28 Nov, 2021 1 commit
    • Viktor Söderqvist's avatar
      Sort out the mess around writable replicas and lookupKeyRead/Write (#9572) · acf3495e
      Viktor Söderqvist authored
      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.
      acf3495e
  15. 18 Nov, 2021 1 commit
    • Binbin's avatar
      Fixes ZPOPMIN/ZPOPMAX wrong replies when count is 0 with non-zset (#9711) · 91e77a0c
      Binbin authored
      Moves ZPOP ... 0 fast exit path after type check to reply with
      WRONGTYPE. In the past it will return an empty array.
      
      Also now count is not allowed to be negative.
      
      see #9680
      
      before:
      ```
      127.0.0.1:6379> set zset str
      OK
      127.0.0.1:6379> zpopmin zset 0
      (empty array)
      127.0.0.1:6379> zpopmin zset -1
      (empty array)
      ```
      
      after:
      ```
      127.0.0.1:6379> set zset str
      OK
      127.0.0.1:6379> zpopmin zset 0
      (error) WRONGTYPE Operation against a key holding the wrong kind of value
      127.0.0.1:6379> zpopmin zset -1
      (error) ERR value is out of range, must be positive
      ```
      91e77a0c
  16. 07 Oct, 2021 1 commit
  17. 26 Sep, 2021 1 commit
    • yoav-steinberg's avatar
      Client eviction ci issues (#9549) · 66002530
      yoav-steinberg authored
      Fixing CI test issues introduced in #8687
      - valgrind warnings in readQueryFromClient when client was freed by processInputBuffer
      - adding DEBUG pause-cron for tests not to be time dependent.
      - skipping a test that depends on socket buffers / events not compatible with TLS
      - making sure client got subscribed by not using deferring client
      66002530
  18. 23 Sep, 2021 2 commits
    • 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
    • Binbin's avatar
      Add ZMPOP/BZMPOP commands. (#9484) · 14d6abd8
      Binbin authored
      This is similar to the recent addition of LMPOP/BLMPOP (#9373), but zset.
      
      Syntax for the new ZMPOP command:
      `ZMPOP numkeys [<key> ...] MIN|MAX [COUNT count]`
      
      Syntax for the new BZMPOP command:
      `BZMPOP timeout numkeys [<key> ...] MIN|MAX [COUNT count]`
      
      Some background:
      - ZPOPMIN/ZPOPMAX take only one key, and can return multiple elements.
      - BZPOPMIN/BZPOPMAX take multiple keys, but return only one element from just one key.
      - ZMPOP/BZMPOP can take multiple keys, and can return multiple elements from just one key.
      
      Note that ZMPOP/BZMPOP can take multiple keys, it eventually operates on just on key.
      And it will propagate as ZPOPMIN or ZPOPMAX with the COUNT option.
      
      As new commands, if we can not pop any elements, the response like:
      - ZMPOP: Return a NIL in both RESP2 and RESP3, unlike ZPOPMIN/ZPOPMAX return emptyarray.
      - BZMPOP: Return a NIL in both RESP2 and RESP3 when timeout is reached, like BZPOPMIN/BZPOPMAX.
      
      For the normal response is nested arrays in RESP2 and RESP3:
      ```
      ZMPOP/BZMPOP
      1) keyname
      2) 1) 1) member1
            2) score1
         2) 1) member2
            2) score2
      
      In RESP2:
      1) "myzset"
      2) 1) 1) "three"
            2) "3"
         2) 1) "two"
            2) "2"
      
      In RESP3:
      1) "myzset"
      2) 1) 1) "three"
            2) (double) 3
         2) 1) "two"
            2) (double) 2
      ```
      14d6abd8
  19. 15 Sep, 2021 1 commit
  20. 09 Sep, 2021 1 commit
    • Binbin's avatar
      Add LMPOP/BLMPOP commands. (#9373) · c50af0ae
      Binbin authored
      We want to add COUNT option for BLPOP.
      But we can't do it without breaking compatibility due to the command arguments syntax.
      So this commit introduce two new commands.
      
      Syntax for the new LMPOP command:
      `LMPOP numkeys [<key> ...] LEFT|RIGHT [COUNT count]`
      
      Syntax for the new BLMPOP command:
      `BLMPOP timeout numkeys [<key> ...] LEFT|RIGHT [COUNT count]`
      
      Some background:
      - LPOP takes one key, and can return multiple elements.
      - BLPOP takes multiple keys, but returns one element from just one key.
      - LMPOP can take multiple keys and return multiple elements from just one key.
      
      Note that LMPOP/BLMPOP  can take multiple keys, it eventually operates on just one key.
      And it will propagate as LPOP or RPOP with the COUNT option.
      
      As a new command, it still return NIL if we can't pop any elements.
      For the normal response is nested arrays in RESP2 and RESP3, like:
      ```
      LMPOP/BLMPOP 
      1) keyname
      2) 1) element1
         2) element2
      ```
      I.e. unlike BLPOP that returns a key name and one element so it uses a flat array,
      and LPOP that returns multiple elements with no key name, and again uses a flat array,
      this one has to return a nested array, and it does for for both RESP2 and RESP3 (like SCAN does)
      
      Some discuss can see: #766 #8824
      c50af0ae
  21. 08 Sep, 2021 1 commit
    • zhaozhao.zz's avatar
      Fix wrong offset when replica pause (#9448) · 1b83353d
      zhaozhao.zz authored
      When a replica paused, it would not apply any commands event the command comes from master, if we feed the non-applied command to replication stream, the replication offset would be wrong, and data would be lost after failover(since replica's `master_repl_offset` grows but command is not applied).
      
      To fix it, here are the changes:
      * Don't update replica's replication offset or propagate commands to sub-replicas when it's paused in `commandProcessed`.
      * Show `slave_read_repl_offset` in info reply.
      * Add an assert to make sure master client should never be blocked unless pause or module (some modules may use block way to do background (parallel) processing and forward original block module command to the replica, it's not a good way but it can work, so the assert excludes module now, but someday in future all modules should rewrite block command to propagate like what `BLPOP` does).
      1b83353d
  22. 02 Aug, 2021 1 commit
    • menwen's avatar
      Fix if consumer is created as a side effect without notify and dirty++ (#9263) · 82c3158a
      menwen authored
      Fixes:
      - When a consumer is created as a side effect, redis didn't issue a keyspace notification,
        nor incremented the server.dirty (affects periodic snapshots).
        this was a bug in XREADGROUP, XCLAIM, and XAUTOCLAIM.
      - When attempting to delete a non-existent consumer, don't issue a keyspace notification
        and don't increment server.dirty
        this was a bug in XGROUP DELCONSUMER
      
      Other changes:
      - Changed streamLookupConsumer() to always only do lookup consumer (never do implicit creation),
        Its last seen time is updated unless the SLC_NO_REFRESH flag is specified.
      - Added streamCreateConsumer() to create a new consumer. When the creation is successful,
        it will notify and dirty++ unless the SCC_NO_NOTIFY or SCC_NO_DIRTIFY flags is specified.
      - Changed streamDelConsumer() to always only do delete consumer.
      - Added keyspace notifications tests about stream events.
      82c3158a
  23. 06 Apr, 2021 1 commit
  24. 25 Mar, 2021 2 commits
    • Igor's avatar
      Introduce fast path to bypass expensive serveClientsBlockedOnKeyByModule call (#8689) · cf0a909e
      Igor authored
      Introduce fast path to bypass expensive serveClientsBlockedOnKeyByModule call
      cf0a909e
    • Oran Agra's avatar
      Fix SLOWLOG for blocked commands (#8632) · 497351ad
      Oran Agra authored
      * SLOWLOG didn't record anything for blocked commands because the client
        was reset and argv was already empty. there was a fix for this issue
        specifically for modules, now it works for all blocked clients.
      * The original command argv (before being re-written) was also reset
        before adding the slowlog on behalf of the blocked command.
      * Latency monitor is now updated regardless of the slowlog flags of the
        command or its execution (their purpose is to hide sensitive info from
        the slowlog, not hide the fact the latency happened).
      * Latency monitor now uses real_cmd rather than c->cmd (which may be
        different if the command got re-written, e.g. GEOADD)
      
      Changes:
      * Unify shared code between slowlog insertion in call() and
        updateStatsOnUnblock(), hopefully prevent future bugs from happening
        due to the later being overlooked.
      * Reset CLIENT_PREVENT_LOGGING in resetClient rather than after command
        processing.
      * Add a test for SLOWLOG and BLPOP
      
      Notes:
      - real_cmd == c->lastcmd, except inside MULTI and Lua.
      - blocked commands never happen in these cases (MULTI / Lua)
      - real_cmd == c->cmd, except for when the command is rewritten (e.g.
        GEOADD)
      - blocked commands (currently) are never rewritten
      - other than the command's CLIENT_PREVENT_LOGGING, and the
        execution flag CLIENT_PREVENT_LOGGING, other cases that we want to
        avoid slowlog are on AOF loading (specifically CMD_CALL_SLOWLOG will
        be off when executed from execCommand that runs from an AOF)
      497351ad
  25. 16 Mar, 2021 1 commit
  26. 29 Jan, 2021 1 commit
    • filipe oliveira's avatar
      Enabled background and reply time tracking on blocked on keys/blocked on... · f0c5052a
      filipe oliveira authored
      Enabled background and reply time tracking on blocked on keys/blocked on background work clients (#7491)
      
      This commit enables tracking time of the background tasks and on replies,
      opening the door for properly tracking commands that rely on blocking / background
       work via the slowlog, latency history, and commandstats. 
      
      Some notes:
      - The time spent blocked waiting for key changes, or blocked on synchronous
        replication is not accounted for. 
      
      - **This commit does not affect latency tracking of commands that are non-blocking
        or do not have background work.** ( meaning that it all stays the same with exception to
        `BZPOPMIN`,`BZPOPMAX`,`BRPOP`,`BLPOP`, etc... and module's commands that rely
        on background threads ). 
      
      -  Specifically for latency history command we've added a new event class named
        `command-unblocking` that will enable latency monitoring on commands that spawn
        background threads to do the work.
      
      - For blocking commands we're now considering the total time of a command as the
        time spent on call() + the time spent on replying when unblocked.
      
      - For Modules commands that rely on background threads we're now considering the
        total time of a command as the time spent on call (main thread) + the time spent on
        the background thread ( if marked within `RedisModule_MeasureTimeStart()` and
        `RedisModule_MeasureTimeEnd()` ) + the time spent on replying (main thread)
      
      To test for this feature we've added a `unit/moduleapi/blockonbackground` test that relies on
      a module that blocks the client and sleeps on the background for a given time. 
      - check blocked command that uses RedisModule_MeasureTimeStart() is tracking background time
      - check blocked command that uses RedisModule_MeasureTimeStart() is tracking background time even in timeout
      - check blocked command with multiple calls RedisModule_MeasureTimeStart()  is tracking the total background time
      - check blocked command without calling RedisModule_MeasureTimeStart() is not reporting background time
      f0c5052a
  27. 19 Jan, 2021 1 commit
    • Viktor Söderqvist's avatar
      Bugfix: Make modules blocked on keys unblock on commands like LPUSH (#8356) · 4985c11b
      Viktor Söderqvist authored
      This was a regression from #7625 (only in 6.2 RC2).
      
      This makes it possible again to implement blocking list and zset
      commands using the modules API.
      
      This commit also includes a test case for the reverse: A module
      unblocks a client blocked on BLPOP by inserting elements using
      RedisModule_ListPush(). This already works, but it was untested.
      4985c11b
  28. 09 Jan, 2021 1 commit
    • Oran Agra's avatar
      CLIENT PAUSE - don't drop together with other blocked clients (#8302) · 430dadaf
      Oran Agra authored
      When the server state changes and blocked clients are being dropped, the
      paused clients should not be dropped, they're safe to keep since unlike
      other blocked types, these commands are not half way though processing,
      and the commands they sent may get rejected according to the new server
      state.
      430dadaf
  29. 08 Jan, 2021 1 commit
  30. 24 Dec, 2020 1 commit
  31. 12 Oct, 2020 1 commit
    • guybe7's avatar
      Minor improvements to module blocked on keys (#7903) · addf47dc
      guybe7 authored
      - Clarify some documentation comments
      - Make sure blocked-on-keys client privdata is accessible
        from withing the timeout callback
      - Handle blocked clients in beforeSleep - In case a key
        becomes "ready" outside of processCommand
      
      See #7879 #7880
      addf47dc
  32. 08 Oct, 2020 1 commit
    • Felipe Machado's avatar
      Adds new pop-push commands (LMOVE, BLMOVE) (#6929) · c3f9e017
      Felipe Machado authored
      
      
      Adding [B]LMOVE <src> <dst> RIGHT|LEFT RIGHT|LEFT. deprecating [B]RPOPLPUSH.
      
      Note that when receiving a BRPOPLPUSH we'll still propagate an RPOPLPUSH,
      but on BLMOVE RIGHT LEFT we'll propagate an LMOVE
      
      improvement to existing tests
      - Replace "after 1000" with "wait_for_condition" when wait for
        clients to block/unblock.
      - Add a pre-existing element to target list on basic tests so
        that we can check if the new element was added to the correct
        side of the list.
      - check command stats on the replica to make sure the right
        command was replicated
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      c3f9e017
  33. 24 Sep, 2020 1 commit
    • valentinogeron's avatar
      Stream: Inconsistency between master and replica some XREADGROUP case (#7526) · 795c454d
      valentinogeron authored
      XREADGROUP auto-creates the consumer inside the consumer group the
      first time it saw it.
      When XREADGROUP is being used with NOACK option, the message will not
      be added into the client's PEL and XGROUP SETID would be propagated.
      When the replica gets the XGROUP SETID it will only update the last delivered
      id of the group, but will not create the consumer.
      
      So, in this commit XGROUP CREATECONSUMER is being added.
      Command pattern: XGROUP CREATECONSUMER <key> <group> <consumer>.
      
      When NOACK option is being used, createconsumer command would be
      propagated as well.
      
      In case of AOFREWRITE, consumer with an empty PEL would be saved with
      XGROUP CREATECONSUMER whereas consumer with pending entries would be
      saved with XCLAIM
      795c454d
  34. 10 Sep, 2020 1 commit
    • Oran Agra's avatar
      Squash merging 125 typo/grammar/comment/doc PRs (#7773) · 1c710385
      Oran Agra authored
      
      
      List of squashed commits or PRs
      ===============================
      
      commit 66801ea
      Author: hwware <wen.hui.ware@gmail.com>
      Date:   Mon Jan 13 00:54:31 2020 -0500
      
          typo fix in acl.c
      
      commit 46f55db
      Author: Itamar Haber <itamar@redislabs.com>
      Date:   Sun Sep 6 18:24:11 2020 +0300
      
          Updates a couple of comments
      
          Specifically:
      
          * RM_AutoMemory completed instead of pointing to docs
          * Updated link to custom type doc
      
      commit 61a2aa0
      Author: xindoo <xindoo@qq.com>
      Date:   Tue Sep 1 19:24:59 2020 +0800
      
          Correct errors in code comments
      
      commit a5871d1
      Author: yz1509 <pro-756@qq.com>
      Date:   Tue Sep 1 18:36:06 2020 +0800
      
          fix typos in module.c
      
      commit 41eede7
      Author: bookug <bookug@qq.com>
      Date:   Sat Aug 15 01:11:33 2020 +0800
      
          docs: fix typos in comments
      
      commit c303c84
      Author: lazy-snail <ws.niu@outlook.com>
      Date:   Fri Aug 7 11:15:44 2020 +0800
      
          fix spelling in redis.conf
      
      commit 1eb76bf
      Author: zhujian <zhujianxyz@gmail.com>
      Date:   Thu Aug 6 15:22:10 2020 +0800
      
          add a missing 'n' in comment
      
      commit 1530ec2
      Author: Daniel Dai <764122422@qq.com>
      Date:   Mon Jul 27 00:46:35 2020 -0400
      
          fix spelling in tracking.c
      
      commit e517b31
      Author: Hunter-Chen <huntcool001@gmail.com>
      Date:   Fri Jul 17 22:33:32 2020 +0800
      
          Update redis.conf
      Co-authored-by: default avatarItamar Haber <itamar@redislabs.com>
      
      commit c300eff
      Author: Hunter-Chen <huntcool001@gmail.com>
      Date:   Fri Jul 17 22:33:23 2020 +0800
      
          Update redis.conf
      Co-authored-by: default avatarItamar Haber <itamar@redislabs.com>
      
      commit 4c058a8
      Author: 陈浩鹏 <chenhaopeng@heytea.com>
      Date:   Thu Jun 25 19:00:56 2020 +0800
      
          Grammar fix and clarification
      
      commit 5fcaa81
      Author: bodong.ybd <bodong.ybd@alibaba-inc.com>
      Date:   Fri Jun 19 10:09:00 2020 +0800
      
          Fix typos
      
      commit 4caca9a
      Author: Pruthvi P <pruthvi@ixigo.com>
      Date:   Fri May 22 00:33:22 2020 +0530
      
          Fix typo eviciton => eviction
      
      commit b2a25f6
      Author: Brad Dunbar <dunbarb2@gmail.com>
      Date:   Sun May 17 12:39:59 2020 -0400
      
          Fix a typo.
      
      commit 12842ae
      Author: hwware <wen.hui.ware@gmail.com>
      Date:   Sun May 3 17:16:59 2020 -0400
      
          fix spelling in redis conf
      
      commit ddba07c
      Author: Chris Lamb <chris@chris-lamb.co.uk>
      Date:   Sat May 2 23:25:34 2020 +0100
      
          Correct a "conflicts" spelling error.
      
      commit 8fc7bf2
      Author: Nao YONASHIRO <yonashiro@r.recruit.co.jp>
      Date:   Thu Apr 30 10:25:27 2020 +0900
      
          docs: fix EXPIRE_FAST_CYCLE_DURATION to ACTIVE_EXPIRE_CYCLE_FAST_DURATION
      
      commit 9b2b67a
      Author: Brad Dunbar <dunbarb2@gmail.com>
      Date:   Fri Apr 24 11:46:22 2020 -0400
      
          Fix a typo.
      
      commit 0746f10
      Author: devilinrust <63737265+devilinrust@users.noreply.github.com>
      Date:   Thu Apr 16 00:17:53 2020 +0200
      
          Fix typos in server.c
      
      commit 92b588d
      Author: benjessop12 <56115861+benjessop12@users.noreply.github.com>
      Date:   Mon Apr 13 13:43:55 2020 +0100
      
          Fix spelling mistake in lazyfree.c
      
      commit 1da37aa
      Merge: 2d4ba28 af347a8c
      Author: hwware <wen.hui.ware@gmail.com>
      Date:   Thu Mar 5 22:41:31 2020 -0500
      
          Merge remote-tracking branch 'upstream/unstable' into expiretypofix
      
      commit 2d4ba28
      Author: hwware <wen.hui.ware@gmail.com>
      Date:   Mon Mar 2 00:09:40 2020 -0500
      
          fix typo in expire.c
      
      commit 1a746f7
      Author: SennoYuki <minakami1yuki@gmail.com>
      Date:   Thu Feb 27 16:54:32 2020 +0800
      
          fix typo
      
      commit 8599b1a
      Author: dongheejeong <donghee950403@gmail.com>
      Date:   Sun Feb 16 20:31:43 2020 +0000
      
          Fix typo in server.c
      
      commit f38d4e8
      Author: hwware <wen.hui.ware@gmail.com>
      Date:   Sun Feb 2 22:58:38 2020 -0500
      
          fix typo in evict.c
      
      commit fe143fc
      Author: Leo Murillo <leonardo.murillo@gmail.com>
      Date:   Sun Feb 2 01:57:22 2020 -0600
      
          Fix a few typos in redis.conf
      
      commit 1ab4d21
      Author: viraja1 <anchan.viraj@gmail.com>
      Date:   Fri Dec 27 17:15:58 2019 +0530
      
          Fix typo in Latency API docstring
      
      commit ca1f70e
      Author: gosth <danxuedexing@qq.com>
      Date:   Wed Dec 18 15:18:02 2019 +0800
      
          fix typo in sort.c
      
      commit a57c06b
      Author: ZYunH <zyunhjob@163.com>
      Date:   Mon Dec 16 22:28:46 2019 +0800
      
          fix-zset-typo
      
      commit b8c92b5
      Author: git-hulk <hulk.website@gmail.com>
      Date:   Mon Dec 16 15:51:42 2019 +0800
      
          FIX: typo in cluster.c, onformation->information
      
      commit 9dd981c
      Author: wujm2007 <jim.wujm@gmail.com>
      Date:   Mon Dec 16 09:37:52 2019 +0800
      
          Fix typo
      
      commit e132d7a
      Author: Sebastien Williams-Wynn <s.williamswynn.mail@gmail.com>
      Date:   Fri Nov 15 00:14:07 2019 +0000
      
          Minor typo change
      
      commit 47f44d5
      Author: happynote3966 <01ssrmikururudevice01@gmail.com>
      Date:   Mon Nov 11 22:08:48 2019 +0900
      
          fix comment typo in redis-cli.c
      
      commit b8bdb0d
      Author: fulei <fulei@kuaishou.com>
      Date:   Wed Oct 16 18:00:17 2019 +0800
      
          Fix a spelling mistake of comments  in defragDictBucketCallback
      
      commit 0def46a
      Author: fulei <fulei@kuaishou.com>
      Date:   Wed Oct 16 13:09:27 2019 +0800
      
          fix some spelling mistakes of comments in defrag.c
      
      commit f3596fd
      Author: Phil Rajchgot <tophil@outlook.com>
      Date:   Sun Oct 13 02:02:32 2019 -0400
      
          Typo and grammar fixes
      
          Redis and its documentation are great -- just wanted to submit a few corrections in the spirit of Hacktoberfest. Thanks for all your work on this project. I use it all the time and it works beautifully.
      
      commit 2b928cd
      Author: KangZhiDong <worldkzd@gmail.com>
      Date:   Sun Sep 1 07:03:11 2019 +0800
      
          fix typos
      
      commit 33aea14
      Author: Axlgrep <axlgrep@gmail.com>
      Date:   Tue Aug 27 11:02:18 2019 +0800
      
          Fixed eviction spelling issues
      
      commit e282a80
      Author: Simen Flatby <simen@oms.no>
      Date:   Tue Aug 20 15:25:51 2019 +0200
      
          Update comments to reflect prop name
      
          In the comments the prop is referenced as replica-validity-factor,
          but it is really named cluster-replica-validity-factor.
      
      commit 74d1f9a
      Author: Jim Green <jimgreen2013@qq.com>
      Date:   Tue Aug 20 20:00:31 2019 +0800
      
          fix comment error, the code is ok
      
      commit eea1407
      Author: Liao Tonglang <liaotonglang@gmail.com>
      Date:   Fri May 31 10:16:18 2019 +0800
      
          typo fix
      
          fix cna't to can't
      
      commit 0da553c
      Author: KAWACHI Takashi <tkawachi@gmail.com>
      Date:   Wed Jul 17 00:38:16 2019 +0900
      
          Fix typo
      
      commit 7fc8fb6
      Author: Michael Prokop <mika@grml.org>
      Date:   Tue May 28 17:58:42 2019 +0200
      
          Typo fixes
      
          s/familar/familiar/
          s/compatiblity/compatibility/
          s/ ot / to /
          s/itsef/itself/
      
      commit 5f46c9d
      Author: zhumoing <34539422+zhumoing@users.noreply.github.com>
      Date:   Tue May 21 21:16:50 2019 +0800
      
          typo-fixes
      
          typo-fixes
      
      commit 321dfe1
      Author: wxisme <850885154@qq.com>
      Date:   Sat Mar 16 15:10:55 2019 +0800
      
          typo fix
      
      commit b4fb131
      Merge: 267e0e6 3df1eb85
      Author: Nikitas Bastas <nikitasbst@gmail.com>
      Date:   Fri Feb 8 22:55:45 2019 +0200
      
          Merge branch 'unstable' of antirez/redis into unstable
      
      commit 267e0e6
      Author: Nikitas Bastas <nikitasbst@gmail.com>
      Date:   Wed Jan 30 21:26:04 2019 +0200
      
          Minor typo fix
      
      commit 30544e7
      Author: inshal96 <39904558+inshal96@users.noreply.github.com>
      Date:   Fri Jan 4 16:54:50 2019 +0500
      
          remove an extra 'a' in the comments
      
      commit 337969d
      Author: BrotherGao <yangdongheng11@gmail.com>
      Date:   Sat Dec 29 12:37:29 2018 +0800
      
          fix typo in redis.conf
      
      commit 9f4b121
      Merge: 423a030 e504583b
      Author: BrotherGao <yangdongheng@xiaomi.com>
      Date:   Sat Dec 29 11:41:12 2018 +0800
      
          Merge branch 'unstable' of antirez/redis into unstable
      
      commit 423a030
      Merge: 42b02b7 46a51cdc
      Author: 杨东衡 <yangdongheng@xiaomi.com>
      Date:   Tue Dec 4 23:56:11 2018 +0800
      
          Merge branch 'unstable' of antirez/redis into unstable
      
      commit 42b02b7
      Merge: 68c0e6e3 b8febe60
      
      
      Author: Dongheng Yang <yangdongheng11@gmail.com>
      Date:   Sun Oct 28 15:54:23 2018 +0800
      
          Merge pull request #1 from antirez/unstable
      
          update local data
      
      commit 714b589
      Author: Christian <crifei93@gmail.com>
      Date:   Fri Dec 28 01:17:26 2018 +0100
      
          fix typo "resulution"
      
      commit e23259d
      Author: garenchan <1412950785@qq.com>
      Date:   Wed Dec 26 09:58:35 2018 +0800
      
          fix typo: segfauls -> segfault
      
      commit a9359f8
      Author: xjp <jianping_xie@aliyun.com>
      Date:   Tue Dec 18 17:31:44 2018 +0800
      
          Fixed REDISMODULE_H spell bug
      
      commit a12c3e4
      Author: jdiaz <jrd.palacios@gmail.com>
      Date:   Sat Dec 15 23:39:52 2018 -0600
      
          Fixes hyperloglog hash function comment block description
      
      commit 770eb11
      Author: 林上耀 <1210tom@163.com>
      Date:   Sun Nov 25 17:16:10 2018 +0800
      
          fix typo
      
      commit fd97fbb
      Author: Chris Lamb <chris@chris-lamb.co.uk>
      Date:   Fri Nov 23 17:14:01 2018 +0100
      
          Correct "unsupported" typo.
      
      commit a85522d
      Author: Jungnam Lee <jungnam.lee@oracle.com>
      Date:   Thu Nov 8 23:01:29 2018 +0900
      
          fix typo in test comments
      
      commit ade8007
      Author: Arun Kumar <palerdot@users.noreply.github.com>
      Date:   Tue Oct 23 16:56:35 2018 +0530
      
          Fixed grammatical typo
      
          Fixed typo for word 'dictionary'
      
      commit 869ee39
      Author: Hamid Alaei <hamid.a85@gmail.com>
      Date:   Sun Aug 12 16:40:02 2018 +0430
      
          fix documentations: (ThreadSafeContextStart/Stop -> ThreadSafeContextLock/Unlock), minor typo
      
      commit f89d158
      Author: Mayank Jain <mayankjain255@gmail.com>
      Date:   Tue Jul 31 23:01:21 2018 +0530
      
          Updated README.md with some spelling corrections.
      
          Made correction in spelling of some misspelled words.
      
      commit 892198e
      Author: dsomeshwar <someshwar.dhayalan@gmail.com>
      Date:   Sat Jul 21 23:23:04 2018 +0530
      
          typo fix
      
      commit 8a4d780
      Author: Itamar Haber <itamar@redislabs.com>
      Date:   Mon Apr 30 02:06:52 2018 +0300
      
          Fixes some typos
      
      commit e3acef6
      Author: Noah Rosamilia <ivoahivoah@gmail.com>
      Date:   Sat Mar 3 23:41:21 2018 -0500
      
          Fix typo in /deps/README.md
      
      commit 04442fb
      Author: WuYunlong <xzsyeb@126.com>
      Date:   Sat Mar 3 10:32:42 2018 +0800
      
          Fix typo in readSyncBulkPayload() comment.
      
      commit 9f36880
      Author: WuYunlong <xzsyeb@126.com>
      Date:   Sat Mar 3 10:20:37 2018 +0800
      
          replication.c comment: run_id -> replid.
      
      commit f866b4a
      Author: Francesco 'makevoid' Canessa <makevoid@gmail.com>
      Date:   Thu Feb 22 22:01:56 2018 +0000
      
          fix comment typo in server.c
      
      commit 0ebc69b
      Author: 줍 <jubee0124@gmail.com>
      Date:   Mon Feb 12 16:38:48 2018 +0900
      
          Fix typo in redis.conf
      
          Fix `five behaviors` to `eight behaviors` in [this sentence ](antirez/redis@unstable/redis.conf#L564)
      
      commit b50a620
      Author: martinbroadhurst <martinbroadhurst@users.noreply.github.com>
      Date:   Thu Dec 28 12:07:30 2017 +0000
      
          Fix typo in valgrind.sup
      
      commit 7d8f349
      Author: Peter Boughton <peter@sorcerersisle.com>
      Date:   Mon Nov 27 19:52:19 2017 +0000
      
          Update CONTRIBUTING; refer doc updates to redis-doc repo.
      
      commit 02dec7e
      Author: Klauswk <klauswk1@hotmail.com>
      Date:   Tue Oct 24 16:18:38 2017 -0200
      
          Fix typo in comment
      
      commit e1efbc8
      Author: chenshi <baiwfg2@gmail.com>
      Date:   Tue Oct 3 18:26:30 2017 +0800
      
          Correct two spelling errors of comments
      
      commit 93327d8
      Author: spacewander <spacewanderlzx@gmail.com>
      Date:   Wed Sep 13 16:47:24 2017 +0800
      
          Update the comment for OBJ_ENCODING_EMBSTR_SIZE_LIMIT's value
      
          The value of OBJ_ENCODING_EMBSTR_SIZE_LIMIT is 44 now instead of 39.
      
      commit 63d361f
      Author: spacewander <spacewanderlzx@gmail.com>
      Date:   Tue Sep 12 15:06:42 2017 +0800
      
          Fix <prevlen> related doc in ziplist.c
      
          According to the definition of ZIP_BIG_PREVLEN and other related code,
          the guard of single byte <prevlen> should be 254 instead of 255.
      
      commit ebe228d
      Author: hanael80 <hanael80@gmail.com>
      Date:   Tue Aug 15 09:09:40 2017 +0900
      
          Fix typo
      
      commit 6b696e6
      Author: Matt Robenolt <matt@ydekproductions.com>
      Date:   Mon Aug 14 14:50:47 2017 -0700
      
          Fix typo in LATENCY DOCTOR output
      
      commit a2ec6ae
      Author: caosiyang <caosiyang@qiyi.com>
      Date:   Tue Aug 15 14:15:16 2017 +0800
      
          Fix a typo: form => from
      
      commit 3ab7699
      Author: caosiyang <caosiyang@qiyi.com>
      Date:   Thu Aug 10 18:40:33 2017 +0800
      
          Fix a typo: replicationFeedSlavesFromMaster() => replicationFeedSlavesFromMasterStream()
      
      commit 72d43ef
      Author: caosiyang <caosiyang@qiyi.com>
      Date:   Tue Aug 8 15:57:25 2017 +0800
      
          fix a typo: servewr => server
      
      commit 707c958
      Author: Bo Cai <charpty@gmail.com>
      Date:   Wed Jul 26 21:49:42 2017 +0800
      
          redis-cli.c typo: conut -> count.
      Signed-off-by: default avatarBo Cai <charpty@gmail.com>
      
      commit b9385b2
      Author: JackDrogon <jack.xsuperman@gmail.com>
      Date:   Fri Jun 30 14:22:31 2017 +0800
      
          Fix some spell problems
      
      commit 20d9230
      Author: akosel <aaronjkosel@gmail.com>
      Date:   Sun Jun 4 19:35:13 2017 -0500
      
          Fix typo
      
      commit b167bfc
      Author: Krzysiek Witkowicz <krzysiekwitkowicz@gmail.com>
      Date:   Mon May 22 21:32:27 2017 +0100
      
          Fix #4008 small typo in comment
      
      commit 2b78ac8
      Author: Jake Clarkson <jacobwclarkson@gmail.com>
      Date:   Wed Apr 26 15:49:50 2017 +0100
      
          Correct typo in tests/unit/hyperloglog.tcl
      
      commit b0f1cdb
      Author: Qi Luo <qiluo-msft@users.noreply.github.com>
      Date:   Wed Apr 19 14:25:18 2017 -0700
      
          Fix typo
      
      commit a90b0f9
      Author: charsyam <charsyam@naver.com>
      Date:   Thu Mar 16 18:19:53 2017 +0900
      
          fix typos
      
          fix typos
      
          fix typos
      
      commit 8430a79
      Author: Richard Hart <richardhart92@gmail.com>
      Date:   Mon Mar 13 22:17:41 2017 -0400
      
          Fixed log message typo in listenToPort.
      
      commit 481a1c2
      Author: Vinod Kumar <kumar003vinod@gmail.com>
      Date:   Sun Jan 15 23:04:51 2017 +0530
      
          src/db.c: Correct "save" -> "safe" typo
      
      commit 586b4d3
      Author: wangshaonan <wshn13@gmail.com>
      Date:   Wed Dec 21 20:28:27 2016 +0800
      
          Fix typo they->the in helloworld.c
      
      commit c1c4b5e
      Author: Jenner <hypxm@qq.com>
      Date:   Mon Dec 19 16:39:46 2016 +0800
      
          typo error
      
      commit 1ee1a3f
      Author: tielei <43289893@qq.com>
      Date:   Mon Jul 18 13:52:25 2016 +0800
      
          fix some comments
      
      commit 11a41fb
      Author: Otto Kekäläinen <otto@seravo.fi>
      Date:   Sun Jul 3 10:23:55 2016 +0100
      
          Fix spelling in documentation and comments
      
      commit 5fb5d82
      Author: francischan <f1ancis621@gmail.com>
      Date:   Tue Jun 28 00:19:33 2016 +0800
      
          Fix outdated comments about redis.c file.
          It should now refer to server.c file.
      
      commit 6b254bc
      Author: lmatt-bit <lmatt123n@gmail.com>
      Date:   Thu Apr 21 21:45:58 2016 +0800
      
          Refine the comment of dictRehashMilliseconds func
      
      SLAVECONF->REPLCONF in comment - by andyli029
      
      commit ee9869f
      Author: clark.kang <charsyam@naver.com>
      Date:   Tue Mar 22 11:09:51 2016 +0900
      
          fix typos
      
      commit f7b3b11
      Author: Harisankar H <harisankarh@gmail.com>
      Date:   Wed Mar 9 11:49:42 2016 +0530
      
          Typo correction: "faield" --> "failed"
      
          Typo correction: "faield" --> "failed"
      
      commit 3fd40fc
      Author: Itamar Haber <itamar@redislabs.com>
      Date:   Thu Feb 25 10:31:51 2016 +0200
      
          Fixes a typo in comments
      
      commit 621c160
      Author: Prayag Verma <prayag.verma@gmail.com>
      Date:   Mon Feb 1 12:36:20 2016 +0530
      
          Fix typo in Readme.md
      
          Spelling mistakes -
          `eviciton` > `eviction`
          `familar` > `familiar`
      
      commit d7d07d6
      Author: WonCheol Lee <toctoc21c@gmail.com>
      Date:   Wed Dec 30 15:11:34 2015 +0900
      
          Typo fixed
      
      commit a4dade7
      Author: Felix Bünemann <buenemann@louis.info>
      Date:   Mon Dec 28 11:02:55 2015 +0100
      
          [ci skip] Improve supervised upstart config docs
      
          This mentions that "expect stop" is required for supervised upstart
          to work correctly. See http://upstart.ubuntu.com/cookbook/#expect-stop
      
      
          for an explanation.
      
      commit d9caba9
      Author: daurnimator <quae@daurnimator.com>
      Date:   Mon Dec 21 18:30:03 2015 +1100
      
          README: Remove trailing whitespace
      
      commit 72d42e5
      Author: daurnimator <quae@daurnimator.com>
      Date:   Mon Dec 21 18:29:32 2015 +1100
      
          README: Fix typo. th => the
      
      commit dd6e957
      Author: daurnimator <quae@daurnimator.com>
      Date:   Mon Dec 21 18:29:20 2015 +1100
      
          README: Fix typo. familar => familiar
      
      commit 3a12b23
      Author: daurnimator <quae@daurnimator.com>
      Date:   Mon Dec 21 18:28:54 2015 +1100
      
          README: Fix typo. eviciton => eviction
      
      commit 2d1d03b
      Author: daurnimator <quae@daurnimator.com>
      Date:   Mon Dec 21 18:21:45 2015 +1100
      
          README: Fix typo. sever => server
      
      commit 3973b06
      Author: Itamar Haber <itamar@garantiadata.com>
      Date:   Sat Dec 19 17:01:20 2015 +0200
      
          Typo fix
      
      commit 4f2e460
      Author: Steve Gao <fu@2token.com>
      Date:   Fri Dec 4 10:22:05 2015 +0800
      
          Update README - fix typos
      
      commit b21667c
      Author: binyan <binbin.yan@nokia.com>
      Date:   Wed Dec 2 22:48:37 2015 +0800
      
          delete redundancy color judge in sdscatcolor
      
      commit 88894c7
      Author: binyan <binbin.yan@nokia.com>
      Date:   Wed Dec 2 22:14:42 2015 +0800
      
          the example output shoule be HelloWorld
      
      commit 2763470
      Author: binyan <binbin.yan@nokia.com>
      Date:   Wed Dec 2 17:41:39 2015 +0800
      
          modify error word keyevente
      Signed-off-by: default avatarbinyan <binbin.yan@nokia.com>
      
      commit 0847b3d
      Author: Bruno Martins <bscmartins@gmail.com>
      Date:   Wed Nov 4 11:37:01 2015 +0000
      
          typo
      
      commit bbb9e9e
      Author: dawedawe <dawedawe@gmx.de>
      Date:   Fri Mar 27 00:46:41 2015 +0100
      
          typo: zimap -> zipmap
      
      commit 5ed297e
      Author: Axel Advento <badwolf.bloodseeker.rev@gmail.com>
      Date:   Tue Mar 3 15:58:29 2015 +0800
      
          Fix 'salve' typos to 'slave'
      
      commit edec9d6
      Author: LudwikJaniuk <ludvig.janiuk@gmail.com>
      Date:   Wed Jun 12 14:12:47 2019 +0200
      
          Update README.md
      Co-Authored-By: default avatarQix <Qix-@users.noreply.github.com>
      
      commit 692a7af
      Author: LudwikJaniuk <ludvig.janiuk@gmail.com>
      Date:   Tue May 28 14:32:04 2019 +0200
      
          grammar
      
      commit d962b0a
      Author: Nick Frost <nickfrostatx@gmail.com>
      Date:   Wed Jul 20 15:17:12 2016 -0700
      
          Minor grammar fix
      
      commit 24fff01aaccaf5956973ada8c50ceb1462e211c6 (typos)
      Author: Chad Miller <chadm@squareup.com>
      Date:   Tue Sep 8 13:46:11 2020 -0400
      
          Fix faulty comment about operation of unlink()
      
      commit 3cd5c1f3326c52aa552ada7ec797c6bb16452355
      Author: Kevin <kevin.xgr@gmail.com>
      Date:   Wed Nov 20 00:13:50 2019 +0800
      
          Fix typo in server.c.
      
      From a83af59 Mon Sep 17 00:00:00 2001
      From: wuwo <wuwo@wacai.com>
      Date: Fri, 17 Mar 2017 20:37:45 +0800
      Subject: [PATCH] falure to failure
      
      From c961896 Mon Sep 17 00:00:00 2001
      From: =?UTF-8?q?=E5=B7=A6=E6=87=B6?= <veficos@gmail.com>
      Date: Sat, 27 May 2017 15:33:04 +0800
      Subject: [PATCH] fix typo
      
      From e600ef2 Mon Sep 17 00:00:00 2001
      From: "rui.zou" <rui.zou@yunify.com>
      Date: Sat, 30 Sep 2017 12:38:15 +0800
      Subject: [PATCH] fix a typo
      
      From c7d07fa Mon Sep 17 00:00:00 2001
      From: Alexandre Perrin <alex@kaworu.ch>
      Date: Thu, 16 Aug 2018 10:35:31 +0200
      Subject: [PATCH] deps README.md typo
      
      From b25cb67 Mon Sep 17 00:00:00 2001
      From: Guy Korland <gkorland@gmail.com>
      Date: Wed, 26 Sep 2018 10:55:37 +0300
      Subject: [PATCH 1/2] fix typos in header
      
      From ad28ca6 Mon Sep 17 00:00:00 2001
      From: Guy Korland <gkorland@gmail.com>
      Date: Wed, 26 Sep 2018 11:02:36 +0300
      Subject: [PATCH 2/2] fix typos
      
      commit 34924cdedd8552466fc22c1168d49236cb7ee915
      Author: Adrian Lynch <adi_ady_ade@hotmail.com>
      Date:   Sat Apr 4 21:59:15 2015 +0100
      
          Typos fixed
      
      commit fd2a1e7
      Author: Jan <jsteemann@users.noreply.github.com>
      Date:   Sat Oct 27 19:13:01 2018 +0200
      
          Fix typos
      
          Fix typos
      
      commit e14e47c1a234b53b0e103c5f6a1c61481cbcbb02
      Author: Andy Lester <andy@petdance.com>
      Date:   Fri Aug 2 22:30:07 2019 -0500
      
          Fix multiple misspellings of "following"
      
      commit 79b948ce2dac6b453fe80995abbcaac04c213d5a
      Author: Andy Lester <andy@petdance.com>
      Date:   Fri Aug 2 22:24:28 2019 -0500
      
          Fix misspelling of create-cluster
      
      commit 1fffde52666dc99ab35efbd31071a4c008cb5a71
      Author: Andy Lester <andy@petdance.com>
      Date:   Wed Jul 31 17:57:56 2019 -0500
      
          Fix typos
      
      commit 204c9ba9651e9e05fd73936b452b9a30be456cfe
      Author: Xiaobo Zhu <xiaobo.zhu@shopee.com>
      Date:   Tue Aug 13 22:19:25 2019 +0800
      
          fix typos
      
      Squashed commit of the following:
      
      commit 1d9aaf8
      Author: danmedani <danmedani@gmail.com>
      Date:   Sun Aug 2 11:40:26 2015 -0700
      
      README typo fix.
      
      Squashed commit of the following:
      
      commit 32bfa7c
      Author: Erik Dubbelboer <erik@dubbelboer.com>
      Date:   Mon Jul 6 21:15:08 2015 +0200
      
      Fixed grammer
      
      Squashed commit of the following:
      
      commit b24f69c
      Author: Sisir Koppaka <sisir.koppaka@gmail.com>
      Date:   Mon Mar 2 22:38:45 2015 -0500
      
      utils/hashtable/rehashing.c: Fix typos
      
      Squashed commit of the following:
      
      commit 4e04082
      Author: Erik Dubbelboer <erik@dubbelboer.com>
      Date:   Mon Mar 23 08:22:21 2015 +0000
      
      Small config file documentation improvements
      
      Squashed commit of the following:
      
      commit acb8773
      Author: ctd1500 <ctd1500@gmail.com>
      Date:   Fri May 8 01:52:48 2015 -0700
      
      Typo and grammar fixes in readme
      
      commit 2eb75b6
      Author: ctd1500 <ctd1500@gmail.com>
      Date:   Fri May 8 01:36:18 2015 -0700
      
      fixed redis.conf comment
      
      Squashed commit of the following:
      
      commit a8249a2
      Author: Masahiko Sawada <sawada.mshk@gmail.com>
      Date:   Fri Dec 11 11:39:52 2015 +0530
      
      Revise correction of typos.
      
      Squashed commit of the following:
      
      commit 3c02028
      Author: zhaojun11 <zhaojun11@jd.com>
      Date:   Wed Jan 17 19:05:28 2018 +0800
      
      Fix typos include two code typos in cluster.c and latency.c
      
      Squashed commit of the following:
      
      commit 9dba47c
      Author: q191201771 <191201771@qq.com>
      Date:   Sat Jan 4 11:31:04 2020 +0800
      
      fix function listCreate comment in adlist.c
      
      Update src/server.c
      
      commit 2c7c2cb536e78dd211b1ac6f7bda00f0f54faaeb
      Author: charpty <charpty@gmail.com>
      Date:   Tue May 1 23:16:59 2018 +0800
      
          server.c typo: modules system dictionary type comment
      Signed-off-by: default avatarcharpty <charpty@gmail.com>
      
      commit a8395323fb63cb59cb3591cb0f0c8edb7c29a680
      Author: Itamar Haber <itamar@redislabs.com>
      Date:   Sun May 6 00:25:18 2018 +0300
      
          Updates test_helper.tcl's help with undocumented options
      
          Specifically:
      
          * Host
          * Port
          * Client
      
      commit bde6f9ced15755cd6407b4af7d601b030f36d60b
      Author: wxisme <850885154@qq.com>
      Date:   Wed Aug 8 15:19:19 2018 +0800
      
          fix comments in deps files
      
      commit 3172474ba991532ab799ee1873439f3402412331
      Author: wxisme <850885154@qq.com>
      Date:   Wed Aug 8 14:33:49 2018 +0800
      
          fix some comments
      
      commit 01b6f2b6858b5cf2ce4ad5092d2c746e755f53f0
      Author: Thor Juhasz <thor@juhasz.pro>
      Date:   Sun Nov 18 14:37:41 2018 +0100
      
          Minor fixes to comments
      
          Found some parts a little unclear on a first read, which prompted me to have a better look at the file and fix some minor things I noticed.
          Fixing minor typos and grammar. There are no changes to configuration options.
          These changes are only meant to help the user better understand the explanations to the various configuration options
      1c710385
  35. 11 Aug, 2020 1 commit
  36. 04 May, 2020 1 commit
  37. 27 Apr, 2020 1 commit
    • Oran Agra's avatar
      Keep track of meaningful replication offset in replicas too · 4447ddc8
      Oran Agra authored
      Now both master and replicas keep track of the last replication offset
      that contains meaningful data (ignoring the tailing pings), and both
      trim that tail from the replication backlog, and the offset with which
      they try to use for psync.
      
      the implication is that if someone missed some pings, or even have
      excessive pings that the promoted replica has, it'll still be able to
      psync (avoid full sync).
      
      the downside (which was already committed) is that replicas running old
      code may fail to psync, since the promoted replica trims pings form it's
      backlog.
      
      This commit adds a test that reproduces several cases of promotions and
      demotions with stale and non-stale pings
      
      Background:
      The mearningful offset on the master was added recently to solve a problem were
      the master is left all alone, injecting PINGs into it's backlog when no one is
      listening and then gets demoted and tries to replicate from a replica that didn't
      have any of the PINGs (or at least not the last ones).
      
      however, consider this case:
      master A has two replicas (B and C) replicating directly from it.
      there's no traffic at all, and also no network issues, just many pings in the
      tail of the backlog. now B gets promoted, A becomes a replica of B, and C
      remains a replica of A. when A gets demoted, it trims the pings from its
      backlog, and successfully replicate from B. however, C is still aware of
      these PINGs, when it'll disconnect and re-connect to A, it'll ask for something
      that's not in the backlog anymore (since A trimmed the tail of it's backlog),
      and be forced to do a full sync (something it didn't have to do before the
      meaningful offset fix).
      
      Besides that, the psync2 test was always failing randomly here and there, it
      turns out the reason were PINGs. Investigating it shows the following scenario:
      
      cycle 1: redis #1 is master, and all the rest are direct replicas of #1
      cycle 2: redis #2 is promoted to master, #1 is a replica of #2 and #3 is replica of #1
      now we see that when #1 is demoted it prints:
      17339:S 21 Apr 2020 11:16:38.523 * Using the meaningful offset 3929963 instead of 3929977 to exclude the final PINGs (14 bytes difference)
      17339:S 21 Apr 2020 11:16:39.391 * Trying a partial resynchronization (request e2b3f8817735fdfe5fa4626766daa938b61419e5:3929964).
      17339:S 21 Apr 2020 11:16:39.392 * Successful partial resynchronization with master.
      and when #3 connects to the demoted #2, #2 says:
      17339:S 21 Apr 2020 11:16:40.084 * Partial resynchronization not accepted: Requested offset for secondary ID was 3929978, but I can reply up to 3929964
      
      so the issue here is that the meaningful offset feature saved the day for the
      demoted master (since it needs to sync from a replica that didn't get the last
      ping), but it didn't help one of the other replicas which did get the last ping.
      4447ddc8
  38. 08 Apr, 2020 1 commit