1. 19 May, 2021 1 commit
  2. 25 Apr, 2021 1 commit
  3. 19 Apr, 2021 1 commit
    • Wen Hui's avatar
      fix invalid master_link_down_since_seconds in info repication (#8785) · 0413fbc7
      Wen Hui authored
      When replica never successfully connect to master, server.repl_down_since
      will be initialized to 0, therefore, the info master_link_down_since_seconds
      was showing the current unix timestamp, which does not make much sense.
      
      This commit fixes the issue by showing master_link_down_since_seconds to -1.
      means the replica never connect to master before.
      
      This commit also resets this variable back to 0 when a replica is turned into
      a master, so that it'll behave the same if the master is later turned into a
      replica again.
      
      The implication of this change is that if some app is checking if the value is > 60
      do something, like conclude the replica is stale, this could case harm (changing
      a big positive number with a small one).
      0413fbc7
  4. 16 Apr, 2021 1 commit
  5. 15 Apr, 2021 1 commit
    • guybe7's avatar
      Add a timeout mechanism for replicas stuck in fullsync (#8762) · d63d0260
      guybe7 authored
      Starting redis 6.0 (part of the TLS feature), diskless master uses pipe from the fork
      child so that the parent is the one sending data to the replicas.
      This mechanism has an issue in which a hung replica will cause the master to wait
      for it to read the data sent to it forever, thus preventing the fork child from terminating
      and preventing the creations of any other forks.
      
      This PR adds a timeout mechanism, much like the ACK-based timeout,
      we disconnect replicas that aren't reading the RDB file fast enough.
      d63d0260
  6. 25 Mar, 2021 1 commit
  7. 14 Mar, 2021 2 commits
    • Huang Zhw's avatar
      Fix typo and outdated comments. (#8640) · 84d056d0
      Huang Zhw authored
      84d056d0
    • Guillem Jover's avatar
      Send the readiness notification when we are ready to accept connections (#8409) · 3a5905fa
      Guillem Jover authored
      On a replica we do accept connections, even though commands accessing
      the database will operate in read-only mode. But the server is still
      already operational and processing commands.
      
      Not sending the readiness notification means that on a HA setup where
      the nodes all start as replicas (with replicaof in the config) with
      a replica that cannot connect to the master server and which might not
      come back in a predictable amount of time or at all, the service
      supervisor will end up timing out the service and terminating it, with
      no option to promote it to be the main instance. This seems counter to
      what the readiness notification is supposed to be signaling.
      
      Instead send the readiness notification when we start accepting
      commands, and then send the various server status changes as that.
      
      Fixes: commit 641c64ad
      Fixes: commit dfb598cf
      3a5905fa
  8. 21 Feb, 2021 1 commit
  9. 09 Feb, 2021 1 commit
  10. 28 Jan, 2021 1 commit
  11. 27 Jan, 2021 1 commit
    • Wang Yuan's avatar
      Implement rdb-only replication (#8303) · ad7d4c6b
      Wang Yuan authored
      In some scenarios, such as remote backup, we only want to get remote
      redis server db snapshot. Currently, redis-cli acts as a replica and
      sends SYNC to redis, but redis still accumulates replication buffer
      in the replica client output buffer, that may result in using vast
      memory, or failing to transfer RDB because of client-output-buffer-limit.
      In this commit, we add 'replconf rdb-only 0|1', redis doesn't send
      incremental replication buffer to them if they send 'replconf rdb-only 1',
      so we can reduce used memory and improve success of getting RDB.
      ad7d4c6b
  12. 08 Jan, 2021 1 commit
  13. 07 Jan, 2021 1 commit
    • YaacovHazan's avatar
      Refactory fork child related infra, Unify child pid · f9dacf8a
      YaacovHazan authored
      This is a refactory commit, isn't suppose to have any actual impact.
      it does the following:
      - keep just one server struct fork child pid variable instead of 3
      - have one server struct variable indicating the purpose of the current fork
        child.
      - redisFork is now responsible of updating the server struct with the pid,
        which means it can be the one that calls updateDictResizePolicy
      - move child info pipe handling into redisFork instead of having them
        repeated outside
      - there are two classes of fork purposes, mutually exclusive group (AOF, RDB,
        Module), and one that can create several forks to coexist in parallel (LDB,
        but maybe Modules some day too, Module API allows for that).
      - minor fix to killRDBChild:
        unlike killAppendOnlyChild and TerminateModuleForkChild, the killRDBChild
        doesn't clear the pid variable or call wait4, so checkChildrenDone does
        the cleanup for it.
        This commit removes the explicit calls to rdbRemoveTempFile, closeChildInfoPipe,
        updateDictResizePolicy, which didn't do any harm, but where unnecessary.
      f9dacf8a
  14. 03 Jan, 2021 1 commit
    • Oran Agra's avatar
      Fix rare assertion as a result of: active defrag while loading (#8281) · 7896debe
      Oran Agra authored
      In #7726 (part of 6.2), we added a mechanism for whileBlockedCron, this
      mechanism has an assertion to make sure the timestamp in
      whileBlockedCron was always set correctly before the blocking operation
      starts.
      
      I now found (thanks to our CI) two bugs in that area:
      1) CONFIG RESETSTAT (if it was allowed during loading) would have
         cleared this var
      2) the call stopLoading (which calls whileBlockedCron) was made too
         early, while the rio is still in use, in which case the update_cksum
         (rdbLoadProgressCallback) may still be called and whileBlockedCron
         can assert.
      7896debe
  15. 24 Dec, 2020 4 commits
    • Oran Agra's avatar
      syncWithMaster: use pipeline for AUTH+REPLCONF*3 · e87c31de
      Oran Agra authored
      The commit deals with the syncWithMaster and the ugly state machine in it.
      It attempts to clean it a bit, but more importantly it uses pipeline for
      part of the work (rather than 7 round trips, we now have 4).
      i.e. the connect and PING are separate, then AUTH + 3 REPLCONF in one pipeline,
      and finally the PSYNC (must be separate since the master has to have an empty
      output buffer).
      e87c31de
    • Oran Agra's avatar
      syncWithMaster: sendSynchronousCommand split to send, and receive · 9bd212cf
      Oran Agra authored
      This is just a refactoring commit.
      
      This function was never actually used as a synchronous (do both send or
      receive), it was always used only ine one of the two modes, which meant it
      has to take extra arguments that are not relevant for the other.
      
      Besides that, a tool that sends a synchronous command, it not something
      we want in our toolbox (synchronous IO in single threaded app is evil).
      
      sendSynchronousCommand was now refactored into separate sending and
      receiving APIs, and the sending part has two variants, one taking vaargs,
      and the other taking argc+argv (and an optional length array which means
      you can use binary sds strings).
      9bd212cf
    • Madelyn Olson's avatar
      Cleanup key tracking documentation and table management (#8039) · 59ff42c4
      Madelyn Olson authored
      Cleanup key tracking documentation, always cleanup the tracking table, and free the tracking table in an async manner when applicable. 
      59ff42c4
    • Madelyn Olson's avatar
      Flow through the error handling path for most errors (#8226) · efaf09ee
      Madelyn Olson authored
      Properly throw errors for invalid replication stream and support https://github.com/redis/redis/pull/8217
      efaf09ee
  16. 17 Dec, 2020 1 commit
  17. 02 Dec, 2020 1 commit
    • Wang Yuan's avatar
      Backup keys to slots map and restore when fail to sync if diskless-load type... · b55a827e
      Wang Yuan authored
      
      Backup keys to slots map and restore when fail to sync if diskless-load type is swapdb in cluster mode (#8108)
      
      When replica diskless-load type is swapdb in cluster mode, we didn't backup
      keys to slots map, so we will lose keys to slots map if fail to sync.
      Now we backup keys to slots map at first, and restore it properly when fail.
      
      This commit includes a refactory/cleanup of the backups mechanism (moving it to db.c and re-structuring it a bit).
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      b55a827e
  18. 22 Nov, 2020 1 commit
    • Wang Yuan's avatar
      Fix diskless replication failure when has non-rdb child process (#8070) · f207e168
      Wang Yuan authored
      If we enable diskless replication, set repl-diskless-sync-delay to 0,
      and master has non-rdb child process such as rewrite aof child, master
      will try to start to a new BGSAVE but fails immediately (before fork)
      when replicas ask for full synchronization, and master always fails
      to start a new BGSAVE and disconnects with replicas until non-rdb
      child process exists.
      
      this bug was introduced in #6271 (not yet released in 6.0.x)
      f207e168
  19. 17 Nov, 2020 1 commit
    • Meir Shpilraien (Spielrein)'s avatar
      Unified MULTI, LUA, and RM_Call with respect to blocking commands (#8025) · d87a0d02
      Meir Shpilraien (Spielrein) authored
      
      
      Blocking command should not be used with MULTI, LUA, and RM_Call. This is because,
      the caller, who executes the command in this context, expects a reply.
      
      Today, LUA and MULTI have a special (and different) treatment to blocking commands:
      
      LUA   - Most commands are marked with no-script flag which are checked when executing
      and command from LUA, commands that are not marked (like XREAD) verify that their
      blocking mode is not used inside LUA (by checking the CLIENT_LUA client flag).
      MULTI - Command that is going to block, first verify that the client is not inside
      multi (by checking the CLIENT_MULTI client flag). If the client is inside multi, they
      return a result which is a match to the empty key with no timeout (for example blpop
      inside MULTI will act as lpop)
      For modules that perform RM_Call with blocking command, the returned results type is
      REDISMODULE_REPLY_UNKNOWN and the caller can not really know what happened.
      
      Disadvantages of the current state are:
      
      No unified approach, LUA, MULTI, and RM_Call, each has a different treatment
      Module can not safely execute blocking command (and get reply or error).
      Though It is true that modules are not like LUA or MULTI and should be smarter not
      to execute blocking commands on RM_Call, sometimes you want to execute a command base
      on client input (for example if you create a module that provides a new scripting
      language like javascript or python).
      While modules (on modules command) can check for REDISMODULE_CTX_FLAGS_LUA or
      REDISMODULE_CTX_FLAGS_MULTI to know not to block the client, there is no way to
      check if the command came from another module using RM_Call. So there is no way
      for a module to know not to block another module RM_Call execution.
      
      This commit adds a way to unify the treatment for blocking clients by introducing
      a new CLIENT_DENY_BLOCKING client flag. On LUA, MULTI, and RM_Call the new flag
      turned on to signify that the client should not be blocked. A blocking command
      verifies that the flag is turned off before blocking. If a blocking command sees
      that the CLIENT_DENY_BLOCKING flag is on, it's not blocking and return results
      which are matches to empty key with no timeout (as MULTI does today).
      
      The new flag is checked on the following commands:
      
      List blocking commands: BLPOP, BRPOP, BRPOPLPUSH, BLMOVE,
      Zset blocking commands: BZPOPMIN, BZPOPMAX
      Stream blocking commands: XREAD, XREADGROUP
      SUBSCRIBE, PSUBSCRIBE, MONITOR
      In addition, the new flag is turned on inside the AOF client, we do not want to
      block the AOF client to prevent deadlocks and commands ordering issues (and there
      is also an existing assert in the code that verifies it).
      
      To keep backward compatibility on LUA, all the no-script flags on existing commands
      were kept untouched. In addition, a LUA special treatment on XREAD and XREADGROUP was kept.
      
      To keep backward compatibility on MULTI (which today allows SUBSCRIBE, and PSUBSCRIBE).
      We added a special treatment on those commands to allow executing them on MULTI.
      
      The only backward compatibility issue that this PR introduces is that now MONITOR
      is not allowed inside MULTI.
      
      Tests were added to verify blocking commands are not blocking the client on LUA, MULTI,
      or RM_Call. Tests were added to verify the module can check for CLIENT_DENY_BLOCKING flag.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      Co-authored-by: default avatarItamar Haber <itamar@redislabs.com>
      d87a0d02
  20. 28 Oct, 2020 1 commit
    • yoav-steinberg's avatar
      Add local address to CLIENT LIST, and a CLIENT KILL filter. (#7913) · 84b3c18f
      yoav-steinberg authored
      Useful when you want to know through which bind address the client connected to
      the server in case of multiple bind addresses.
      
      - Adding `laddr` field to CLIENT list showing the local (bind) address.
      - Adding `LADDR` option to CLIENT KILL to kill all the clients connected
        to a specific local address.
      - Refactoring to share code.
      84b3c18f
  21. 13 Oct, 2020 1 commit
    • Wang Yuan's avatar
      Remove temporary aof and rdb files in a background thread (#7905) · aaacb8c9
      Wang Yuan authored
      If we fail or stop to rewrite aof, we need to remove temporary aof.
      We also remove temporary rdb when replicas abort to receive rdb.
      But currently we delete them in main thread, to avoid blocking,
      we should use bg_unlink to remove them in a background thread.
      
      Btw, we have already used this way to removed child process temporary rdb.
      aaacb8c9
  22. 25 Sep, 2020 1 commit
    • WuYunlong's avatar
      Add fsync to readSyncBulkPayload(). (#7839) · 0d62caab
      WuYunlong authored
      We should sync temp DB file before renaming as rdb_fsync_range does not use
      flag `SYNC_FILE_RANGE_WAIT_AFTER`.
      
      Refer to `Linux Programmer's Manual`:
      SYNC_FILE_RANGE_WAIT_AFTER
          Wait upon write-out of all pages in the range after performing any write.
      0d62caab
  23. 22 Sep, 2020 1 commit
    • Yossi Gottlieb's avatar
      Fix occasional hangs on replication reconnection. (#7830) · 1980f639
      Yossi Gottlieb authored
      This happens only on diskless replicas when attempting to reconnect after 
      failing to load an RDB file. It is more likely to occur with larger datasets.
      
      After reconnection is initiated, replicationEmptyDbCallback() may get called 
      and try to write to an unconnected socket. This triggered another issue where
      the connection is put into an error state and the connect handler never gets
      called. The problem is a regression introduced by commit c17e597d.
      1980f639
  24. 17 Sep, 2020 1 commit
    • Wang Yuan's avatar
      Implement redisAtomic to replace _Atomic C11 builtin (#7707) · 445a4b66
      Wang Yuan authored
      Redis 6.0 introduces I/O threads, it is so cool and efficient, we use C11
      _Atomic to establish inter-thread synchronization without mutex. But the
      compiler that must supports C11 _Atomic can compile redis code, that brings a
      lot of inconvenience since some common platforms can't support by default such
      as CentOS7, so we want to implement redis atomic type to make it more portable.
      
      We have implemented our atomic variable for redis that only has 'relaxed'
      operations in src/atomicvar.h, so we implement some operations with
      'sequentially-consistent', just like the default behavior of C11 _Atomic that
      can establish inter-thread synchronization. And we replace all uses of C11
      _Atomic with redis atomic variable.
      
      Our implementation of redis atomic variable uses C11 _Atomic, __atomic or
      __sync macros if available, it supports most common platforms, and we will
      detect automatically which feature we use. In Makefile we use a dummy file to
      detect if the compiler supports C11 _Atomic. Now for gcc, we can compile redis
      code theoretically if your gcc version is not less than 4.1.2(starts to support
      __sync_xxx operations). Otherwise, we remove use mutex fallback to implement
      redis atomic variable for performance and test. You will get compiling errors
      if your compiler doesn't support all features of above.
      
      For cover redis atomic variable tests, we add other CI jobs that build redis on
      CentOS6 and CentOS7 and workflow daily jobs that run the tests on them.
      For them, we just install gcc by default in order to cover different compiler
      versions, gcc is 4.4.7 by default installation on CentOS6 and 4.8.5 on CentOS7.
      
      We restore the feature that we can test redis with Helgrind to find data race
      errors. But you need install Valgrind in the default path configuration firstly
      before running your tests, since we use macros in helgrind.h to tell Helgrind
      inter-thread happens-before relationship explicitly for avoiding false positives.
      Please open an issue on github if you find data race errors relate to this commit.
      
      Unrelated:
      - Fix redefinition of typedef 'RedisModuleUserChangedFunc'
        For some old version compilers, they will report errors or warnings, if we
        re-define function type.
      445a4b66
  25. 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 1e...
      1c710385
  26. 06 Sep, 2020 1 commit
    • Oran Agra's avatar
      if diskless repl child is killed, make sure to reap the pid (#7742) · 573246f7
      Oran Agra authored
      Starting redis 6.0 and the changes we made to the diskless master to be
      suitable for TLS, I made the master avoid reaping (wait3) the pid of the
      child until we know all replicas are done reading their rdb.
      
      I did that in order to avoid a state where the rdb_child_pid is -1 but
      we don't yet want to start another fork (still busy serving that data to
      replicas).
      
      It turns out that the solution used so far was problematic in case the
      fork child was being killed (e.g. by the kernel OOM killer), in that
      case there's a chance that we currently disabled the read event on the
      rdb pipe, since we're waiting for a replica to become writable again.
      and in that scenario the master would have never realized the child
      exited, and the replica will remain hung too.
      Note that there's no mechanism to detect a hung replica while it's in
      rdb transfer state.
      
      The solution here is to add another pipe which is used by the parent to
      tell the child it is safe to exit. this mean that when the child exits,
      for whatever reason, it is safe to reap it.
      
      Besides that, i'm re-introducing an adjustment to REPLCONF ACK which was
      part of #6271 (Accelerate diskless master connections) but was dropped
      when that PR was rebased after the TLS fork/pipe changes (5a477946).
      Now that RdbPipeCleanup no longer calls checkChildrenDone, and the ACK
      has chance to detect that the child exited, it should be the one to call
      it so that we don't have to wait for cron (server.hz) to do that.
      573246f7
  27. 19 Aug, 2020 1 commit
  28. 13 Aug, 2020 1 commit
    • caozb's avatar
      wait command optimization (#7333) · d10b2f31
      caozb authored
      
      
      Client that issued WAIT last will most likely have the highest replication offset, so imagine a probably common case where all clients are waiting for the same number of replicas. we prefer the loop to start from the last client (one waiting for the highest offset), so that the optimization in the function will call replicationCountAcksByOffset for each client until it found a good one, and stop calling it for the rest of the clients.
      the way the loop was implemented would mean that in such case it is likely to call replicationCountAcksByOffset for all clients.
      
      Note: the change from > to >= is not directly related to the above.
      Co-authored-by: default avatar曹正斌 <caozb@jiedaibao.com>
      d10b2f31
  29. 12 Aug, 2020 1 commit
    • Yossi Gottlieb's avatar
      Add oom-score-adj configuration option to control Linux OOM killer. (#1690) · 2530dc0e
      Yossi Gottlieb authored
      Add Linux kernel OOM killer control option.
      
      This adds the ability to control the Linux OOM killer oom_score_adj
      parameter for all Redis processes, depending on the process role (i.e.
      master, replica, background child).
      
      A oom-score-adj global boolean flag control this feature. In addition,
      specific values can be configured using oom-score-adj-values if
      additional tuning is required.
      2530dc0e
  30. 06 Aug, 2020 1 commit
    • Oran Agra's avatar
      Accelerate diskless master connections, and general re-connections (#6271) · c17e597d
      Oran Agra authored
      Diskless master has some inherent latencies.
      1) fork starts with delay from cron rather than immediately
      2) replica is put online only after an ACK. but the ACK
         was sent only once a second.
      3) but even if it would arrive immediately, it will not
         register in case cron didn't yet detect that the fork is done.
      
      Besides that, when a replica disconnects, it doesn't immediately
      attempts to re-connect, it waits for replication cron (one per second).
      in case it was already online, it may be important to try to re-connect
      as soon as possible, so that the backlog at the master doesn't vanish.
      
      In case it disconnected during rdb transfer, one can argue that it's
      not very important to re-connect immediately, but this is needed for the
      "diskless loading short read" test to be able to run 100 iterations in 5
      seconds, rather than 3 (waiting for replication cron re-connection)
      
      changes in this commit:
      1) sync command starts a fork immediately if no sync_delay is configured
      2) replica sends REPLCONF ACK when done reading the rdb (rather than on 1s cron)
      3) when a replica unexpectedly disconnets, it immediately tries to
         re-connect rather than waiting 1s
      4) when when a child exits, if there is another replica waiting, we spawn a new
         one right away, instead of waiting for 1s replicationCron.
      5) added a call to connectWithMaster from replicationSetMaster. which is called
         from the REPLICAOF command but also in 3 places in cluster.c, in all of
         these the connection attempt will now be immediate instead of delayed by 1
         second.
      
      side note:
      we can add a call to rdbPipeReadHandler in replconfCommand when getting
      a REPLCONF ACK from the replica to solve a race where the replica got
      the entire rdb and EOF marker before we detected that the pipe was
      closed.
      in the test i did see this race happens in one about of some 300 runs,
      but i concluded that this race is unlikely in real life (where the
      replica is on another host and we're more likely to first detect the
      pipe was closed.
      the test runs 100 iterations in 3 seconds, so in some cases it'll take 4
      seconds instead (waiting for another REPLCONF ACK).
      
      Removing unneeded startBgsaveForReplication from updateSlavesWaitingForBgsave
      Now that CheckChildrenDone is calling the new replicationStartPendingFork
      (extracted from serverCron) there's actually no need to call
      startBgsaveForReplication from updateSlavesWaitingForBgsave anymore,
      since as soon as updateSlavesWaitingForBgsave returns, CheckChildrenDone is
      calling replicationStartPendingFork that handles that anyway.
      The code in updateSlavesWaitingForBgsave had a bug in which it ignored
      repl-diskless-sync-delay, but removing that code shows that this bug was
      hiding another bug, which is that the max_idle should have used >= and
      not >, this one second delay has a big impact on my new test.
      c17e597d
  31. 31 Jul, 2020 1 commit
  32. 20 Jul, 2020 1 commit
  33. 14 Jul, 2020 1 commit
    • Oran Agra's avatar
      diskless master disconnect replicas when rdb child failed (#7518) · a176cb56
      Oran Agra authored
      in case the rdb child failed, crashed or terminated unexpectedly redis
      would have marked the replica clients with repl_put_online_on_ack and
      then kill them only after a minute when no ack was received.
      
      it would not stream anything to these connections, so the only effect of
      this bug is a delay of 1 minute in the replicas attempt to re-connect.
      a176cb56
  34. 06 Jun, 2020 2 commits
  35. 28 May, 2020 1 commit