1. 02 Nov, 2021 1 commit
    • zhaozhao.zz's avatar
      rebuild replication backlog index when master restart (#9720) · d08f0552
      zhaozhao.zz authored
      After PR #9166 , replication backlog is not a real block of memory, just contains a
      reference points to replication buffer's block and the blocks index (to accelerate
      search offset when partial sync), so we need update both replication buffer's block's
      offset and replication backlog blocks index's offset when master restart from RDB,
      since the `server.master_repl_offset` is changed.
      The implications of this bug was just a slow search, but not a replication failure.
      d08f0552
  2. 25 Oct, 2021 1 commit
    • Wang Yuan's avatar
      Replication backlog and replicas use one global shared replication buffer (#9166) · c1718f9d
      Wang Yuan authored
      ## Background
      For redis master, one replica uses one copy of replication buffer, that is a big waste of memory,
      more replicas more waste, and allocate/free memory for every reply list also cost much.
      If we set client-output-buffer-limit small and write traffic is heavy, master may disconnect with
      replicas and can't finish synchronization with replica. If we set  client-output-buffer-limit big,
      master may be OOM when there are many replicas that separately keep much memory.
      Because replication buffers of different replica client are the same, one simple idea is that
      all replicas only use one replication buffer, that will effectively save memory.
      
      Since replication backlog content is the same as replicas' output buffer, now we
      can discard replication backlog memory and use global shared replication buffer
      to implement replication backlog mechanism.
      
      ## Implementation
      I create one global "replication buffer" which contains content of replication stream.
      The structure of "replication buffer" is similar to the reply list that exists in every client.
      But the node of list is `replBufBlock`, which has `id, repl_offset, refcount` fields.
      ```c
      /* Replication buffer blocks is the list of replBufBlock.
       *
       * +--------------+       +--------------+       +--------------+
       * | refcount = 1 |  ...  | refcount = 0 |  ...  | refcount = 2 |
       * +--------------+       +--------------+       +--------------+
       *      |                                            /       \
       *      |                                           /         \
       *      |                                          /           \
       *  Repl Backlog                               Replia_A      Replia_B
       * 
       * Each replica or replication backlog increments only the refcount of the
       * 'ref_repl_buf_node' which it points to. So when replica walks to the next
       * node, it should first increase the next node's refcount, and when we trim
       * the replication buffer nodes, we remove node always from the head node which
       * refcount is 0. If the refcount of the head node is not 0, we must stop
       * trimming and never iterate the next node. */
      
      /* Similar with 'clientReplyBlock', it is used for shared buffers between
       * all replica clients and replication backlog. */
      typedef struct replBufBlock {
          int refcount;           /* Number of replicas or repl backlog using. */
          long long id;           /* The unique incremental number. */
          long long repl_offset;  /* Start replication offset of the block. */
          size_t size, used;
          char buf[];
      } replBufBlock;
      ```
      So now when we feed replication stream into replication backlog and all replicas, we only need
      to feed stream into replication buffer `feedReplicationBuffer`. In this function, we set some fields of
      replication backlog and replicas to references of the global replication buffer blocks. And we also
      need to check replicas' output buffer limit to free if exceeding `client-output-buffer-limit`, and trim
      replication backlog if exceeding `repl-backlog-size`.
      
      When sending reply to replicas, we also need to iterate replication buffer blocks and send its
      content, when totally sending one block for replica, we decrease current node count and
      increase the next current node count, and then free the block which reference is 0 from the
      head of replication buffer blocks.
      
      Since now we use linked list to manage replication backlog, it may cost much time for iterating
      all linked list nodes to find corresponding replication buffer node. So we create a rax tree to
      store some nodes  for index, but to avoid rax tree occupying too much memory, i record
      one per 64 nodes for index.
      
      Currently, to make partial resynchronization as possible as much, we always let replication
      backlog as the last reference of replication buffer blocks, backlog size may exceeds our setting
      if slow replicas that reference vast replication buffer blocks, and this method doesn't increase
      memory usage since they share replication buffer. To avoid freezing server for freeing unreferenced
      replication buffer blocks when we need to trim backlog for exceeding backlog size setting,
      we trim backlog incrementally (free 64 blocks per call now), and make it faster in
      `beforeSleep` (free 640 blocks).
      
      ### Other changes
      - `mem_total_replication_buffers`: we add this field in INFO command, it means the total
        memory of replication buffers used.
      - `mem_clients_slaves`:  now even replica is slow to replicate, and its output buffer memory
        is not 0, but it still may be 0, since replication backlog and replicas share one global replication
        buffer, only if replication buffer memory is more than the repl backlog setting size, we consider
        the excess as replicas' memory. Otherwise, we think replication buffer memory is the consumption
        of repl backlog.
      - Key eviction
        Since all replicas and replication backlog share global replication buffer, we think only the
        part of exceeding backlog size the extra separate consumption of replicas.
        Because we trim backlog incrementally in the background, backlog size may exceeds our
        setting if slow replicas that reference vast replication buffer blocks disconnect.
        To avoid massive eviction loop, we don't count the delayed freed replication backlog into
        used memory even if there are no replicas, i.e. we also regard this memory as replicas's memory.
      - `client-output-buffer-limit` check for replica clients
        It doesn't make sense to set the replica clients output buffer limit lower than the repl-backlog-size
        config (partial sync will succeed and then replica will get disconnected). Such a configuration is
        ignored (the size of repl-backlog-size will be used). This doesn't have memory consumption
        implications since the replica client will share the backlog buffers memory.
      - Drop replication backlog after loading data if needed
        We always create replication backlog if server is a master, we need it because we put DELs in
        it when loading expired keys in RDB, but if RDB doesn't have replication info or there is no rdb,
        it is not possible to support partial resynchronization, to avoid extra memory of replication backlog,
        we drop it.
      - Multi IO threads
       Since all replicas and replication backlog use global replication buffer,  if I/O threads are enabled,
        to guarantee data accessing thread safe, we must let main thread handle sending the output buffer
        to all replicas. But before, other IO threads could handle sending output buffer of all replicas.
      
      ## Other optimizations
      This solution resolve some other problem:
      - When replicas disconnect with master since of out of output buffer limit, releasing the output
        buffer of replicas may freeze server if we set big `client-output-buffer-limit` for replicas, but now,
        it doesn't cause freezing.
      - This implementation may mitigate reply list copy cost time(also freezes server) when one replication
        has huge reply buffer and another replica can copy buffer for full synchronization. now, we just copy
        reference info, it is very light.
      - If we set replication backlog size big, it also may cost much time to copy replication backlog into
        replica's output buffer. But this commit eliminates this problem.
      - Resizing replication backlog size doesn't empty current replication backlog content.
      c1718f9d
  3. 24 Oct, 2021 1 commit
  4. 20 Oct, 2021 1 commit
    • guybe7's avatar
      Treat subcommands as commands (#9504) · 43e736f7
      guybe7 authored
      ## Intro
      
      The purpose is to allow having different flags/ACL categories for
      subcommands (Example: CONFIG GET is ok-loading but CONFIG SET isn't)
      
      We create a small command table for every command that has subcommands
      and each subcommand has its own flags, etc. (same as a "regular" command)
      
      This commit also unites the Redis and the Sentinel command tables
      
      ## Affected commands
      
      CONFIG
      Used to have "admin ok-loading ok-stale no-script"
      Changes:
      1. Dropped "ok-loading" in all except GET (this doesn't change behavior since
      there were checks in the code doing that)
      
      XINFO
      Used to have "read-only random"
      Changes:
      1. Dropped "random" in all except CONSUMERS
      
      XGROUP
      Used to have "write use-memory"
      Changes:
      1. Dropped "use-memory" in all except CREATE and CREATECONSUMER
      
      COMMAND
      No changes.
      
      MEMORY
      Used to have "random read-only"
      Changes:
      1. Dropped "random" in PURGE and USAGE
      
      ACL
      Used to have "admin no-script ok-loading ok-stale"
      Changes:
      1. Dropped "admin" in WHOAMI, GENPASS, and CAT
      
      LATENCY
      No changes.
      
      MODULE
      No changes.
      
      SLOWLOG
      Used to have "admin random ok-loading ok-stale"
      Changes:
      1. Dropped "random" in RESET
      
      OBJECT
      Used to have "read-only random"
      Changes:
      1. Dropped "random" in ENCODING and REFCOUNT
      
      SCRIPT
      Used to have "may-replicate no-script"
      Changes:
      1. Dropped "may-replicate" in all except FLUSH and LOAD
      
      CLIENT
      Used to have "admin no-script random ok-loading ok-stale"
      Changes:
      1. Dropped "random" in all except INFO and LIST
      2. Dropped "admin" in ID, TRACKING, CACHING, GETREDIR, INFO, SETNAME, GETNAME, and REPLY
      
      STRALGO
      No changes.
      
      PUBSUB
      No changes.
      
      CLUSTER
      Changes:
      1. Dropped "admin in countkeysinslots, getkeysinslot, info, nodes, keyslot, myid, and slots
      
      SENTINEL
      No changes.
      
      (note that DEBUG also fits, but we decided not to convert it since it's for
      debugging and anyway undocumented)
      
      ## New sub-command
      This commit adds another element to the per-command output of COMMAND,
      describing the list of subcommands, if any (in the same structure as "regular" commands)
      Also, it adds a new subcommand:
      ```
      COMMAND LIST [FILTERBY (MODULE <module-name>|ACLCAT <cat>|PATTERN <pattern>)]
      ```
      which returns a set of all commands (unless filters), but excluding subcommands.
      
      ## Module API
      A new module API, RM_CreateSubcommand, was added, in order to allow
      module writer to define subcommands
      
      ## ACL changes:
      1. Now, that each subcommand is actually a command, each has its own ACL id.
      2. The old mechanism of allowed_subcommands is redundant
      (blocking/allowing a subcommand is the same as blocking/allowing a regular command),
      but we had to keep it, to support the widespread usage of allowed_subcommands
      to block commands with certain args, that aren't subcommands (e.g. "-select +select|0").
      3. I have renamed allowed_subcommands to allowed_firstargs to emphasize the difference.
      4. Because subcommands are commands in ACL too, you can now use "-" to block subcommands
      (e.g. "+client -client|kill"), which wasn't possible in the past.
      5. It is also possible to use the allowed_firstargs mechanism with subcommand.
      For example: `+config -config|set +config|set|loglevel` will block all CONFIG SET except
      for setting the log level.
      6. All of the ACL changes above required some amount of refactoring.
      
      ## Misc
      1. There are two approaches: Either each subcommand has its own function or all
         subcommands use the same function, determining what to do according to argv[0].
         For now, I took the former approaches only with CONFIG and COMMAND,
         while other commands use the latter approach (for smaller blamelog diff).
      2. Deleted memoryGetKeys: It is no longer needed because MEMORY USAGE now uses the "range" key spec.
      4. Bugfix: GETNAME was missing from CLIENT's help message.
      5. Sentinel and Redis now use the same table, with the same function pointer.
         Some commands have a different implementation in Sentinel, so we redirect
         them (these are ROLE, PUBLISH, and INFO).
      6. Command stats now show the stats per subcommand (e.g. instead of stats just
         for "config" you will have stats for "config|set", "config|get", etc.)
      7. It is now possible to use COMMAND directly on subcommands:
         COMMAND INFO CONFIG|GET (The pipeline syntax was inspired from ACL, and
         can be used in functions lookupCommandBySds and lookupCommandByCString)
      8. STRALGO is now a container command (has "help")
      
      ## Breaking changes:
      1. Command stats now show the stats per subcommand (see (5) above)
      43e736f7
  5. 03 Oct, 2021 1 commit
    • Binbin's avatar
      Cleanup typos, incorrect comments, and fixed small memory leak in redis-cli (#9153) · dd3ac97f
      Binbin authored
      1. Remove forward declarations from header files to functions that do not exist:
      hmsetCommand and rdbSaveTime.
      2. Minor phrasing fixes in #9519
      3. Add missing sdsfree(title) and fix typo in redis-benchmark.
      4. Modify some error comments in some zset commands.
      5. Fix copy-paste bug comment in syncWithMaster about `ip-address`.
      dd3ac97f
  6. 23 Sep, 2021 1 commit
    • yoav-steinberg's avatar
      Client eviction (#8687) · 2753429c
      yoav-steinberg authored
      
      
      ### Description
      A mechanism for disconnecting clients when the sum of all connected clients is above a
      configured limit. This prevents eviction or OOM caused by accumulated used memory
      between all clients. It's a complimentary mechanism to the `client-output-buffer-limit`
      mechanism which takes into account not only a single client and not only output buffers
      but rather all memory used by all clients.
      
      #### Design
      The general design is as following:
      * We track memory usage of each client, taking into account all memory used by the
        client (query buffer, output buffer, parsed arguments, etc...). This is kept up to date
        after reading from the socket, after processing commands and after writing to the socket.
      * Based on the used memory we sort all clients into buckets. Each bucket contains all
        clients using up up to x2 memory of the clients in the bucket below it. For example up
        to 1m clients, up to 2m clients, up to 4m clients, ...
      * Before processing a command and before sleep we check if we're over the configured
        limit. If we are we start disconnecting clients from larger buckets downwards until we're
        under the limit.
      
      #### Config
      `maxmemory-clients` max memory all clients are allowed to consume, above this threshold
      we disconnect clients.
      This config can either be set to 0 (meaning no limit), a size in bytes (possibly with MB/GB
      suffix), or as a percentage of `maxmemory` by using the `%` suffix (e.g. setting it to `10%`
      would mean 10% of `maxmemory`).
      
      #### Important code changes
      * During the development I encountered yet more situations where our io-threads access
        global vars. And needed to fix them. I also had to handle keeps the clients sorted into the
        memory buckets (which are global) while their memory usage changes in the io-thread.
        To achieve this I decided to simplify how we check if we're in an io-thread and make it
        much more explicit. I removed the `CLIENT_PENDING_READ` flag used for checking
        if the client is in an io-thread (it wasn't used for anything else) and just used the global
        `io_threads_op` variable the same way to check during writes.
      * I optimized the cleanup of the client from the `clients_pending_read` list on client freeing.
        We now store a pointer in the `client` struct to this list so we don't need to search in it
        (`pending_read_list_node`).
      * Added `evicted_clients` stat to `INFO` command.
      * Added `CLIENT NO-EVICT ON|OFF` sub command to exclude a specific client from the
        client eviction mechanism. Added corrosponding 'e' flag in the client info string.
      * Added `multi-mem` field in the client info string to show how much memory is used up
        by buffered multi commands.
      * Client `tot-mem` now accounts for buffered multi-commands, pubsub patterns and
        channels (partially), tracking prefixes (partially).
      * CLIENT_CLOSE_ASAP flag is now handled in a new `beforeNextClient()` function so
        clients will be disconnected between processing different clients and not only before sleep.
        This new function can be used in the future for work we want to do outside the command
        processing loop but don't want to wait for all clients to be processed before we get to it.
        Specifically I wanted to handle output-buffer-limit related closing before we process client
        eviction in case the two race with each other.
      * Added a `DEBUG CLIENT-EVICTION` command to print out info about the client eviction
        buckets.
      * Each client now holds a pointer to the client eviction memory usage bucket it belongs to
        and listNode to itself in that bucket for quick removal.
      * Global `io_threads_op` variable now can contain a `IO_THREADS_OP_IDLE` value
        indicating no io-threading is currently being executed.
      * In order to track memory used by each clients in real-time we can't rely on updating
        these stats in `clientsCron()` alone anymore. So now I call `updateClientMemUsage()`
        (used to be `clientsCronTrackClientsMemUsage()`) after command processing, after
        writing data to pubsub clients, after writing the output buffer and after reading from the
        socket (and maybe other places too). The function is written to be fast.
      * Clients are evicted if needed (with appropriate log line) in `beforeSleep()` and before
        processing a command (before performing oom-checks and key-eviction).
      * All clients memory usage buckets are grouped as follows:
        * All clients using less than 64k.
        * 64K..128K
        * 128K..256K
        * ...
        * 2G..4G
        * All clients using 4g and up.
      * Added client-eviction.tcl with a bunch of tests for the new mechanism.
      * Extended maxmemory.tcl to test the interaction between maxmemory and
        maxmemory-clients settings.
      * Added an option to flag a numeric configuration variable as a "percent", this means that
        if we encounter a '%' after the number in the config file (or config set command) we
        consider it as valid. Such a number is store internally as a negative value. This way an
        integer value can be interpreted as either a percent (negative) or absolute value (positive).
        This is useful for example if some numeric configuration can optionally be set to a percentage
        of something else.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      2753429c
  7. 09 Sep, 2021 1 commit
    • Wang Yuan's avatar
      Delay to discard cached master when full synchronization (#9398) · cee3d67f
      Wang Yuan authored
      * Delay to discard cache master when full synchronization
      * Don't disconnect with replicas before loading transferred RDB when full sync
      
      Previously, once replica need to start full synchronization with master,
      it will discard cached master whatever full synchronization is failed or
      not. 
      Now we discard cached master only when transferring RDB is finished
      and start to change data space, this make replica could start partial
      resynchronization with another new master if new master is failed
      during full synchronization.
      cee3d67f
  8. 05 Aug, 2021 1 commit
    • yoav-steinberg's avatar
      dict struct memory optimizations (#9228) · 5e908a29
      yoav-steinberg authored
      Reduce dict struct memory overhead
      on 64bit dict size goes down from jemalloc's 96 byte bin to its 56 byte bin.
      
      summary of changes:
      - Remove `privdata` from callbacks and dict creation. (this affects many files, see "Interface change" below).
      - Meld `dictht` struct into the `dict` struct to eliminate struct padding. (this affects just dict.c and defrag.c)
      - Eliminate the `sizemask` field, can be calculated from size when needed.
      - Convert the `size` field into `size_exp` (exponent), utilizes one byte instead of 8.
      
      Interface change: pass dict pointer to dict type call back functions.
      This is instead of passing the removed privdata field. In the future if
      we'd like to have private data in the callbacks we can extract it from
      the dict type. We can extend dictType to include a custom dict struct
      allocator and use it to allocate more data at the end of the dict
      struct. This data can then be used to store private data later acccessed
      by the callbacks.
      5e908a29
  9. 02 Aug, 2021 1 commit
    • Binbin's avatar
      Modify some error logs printing level. (#9306) · 4000cb7d
      Binbin authored
      1. In sendBulkToSlave, we used LL_VERBOSE in the past, changed to
      LL_WARNING. (all the other places that do freeClient(slave) use LL_WARNING)
      2. The old style LOG_WARNING, chang it to LL_WARNING. Introduced in an
      old pr (#1690).
      4000cb7d
  10. 30 Jul, 2021 1 commit
  11. 06 Jul, 2021 1 commit
  12. 28 Jun, 2021 1 commit
    • Wang Yuan's avatar
      Remove unnecessary replication backlog memory copy (#9157) · 4fa3e230
      Wang Yuan authored
      in the past, the reply list was a list of sds objects, so this didn't have any overhead,
      but now addReplySds just copies the data from the sds and frees it, so there's no
      need to make a copy of the buffer before copying again.
      this reduces an excessive allocation and free and a memcpy.
      4fa3e230
  13. 24 Jun, 2021 1 commit
    • Yossi Gottlieb's avatar
      Add bind-source-addr configuration argument. (#9142) · f233c4c5
      Yossi Gottlieb authored
      In the past, the first bind address that was explicitly specified was
      also used to bind outgoing connections. This could result with some
      problems. For example: on some systems using `bind 127.0.0.1` would
      result with outgoing connections also binding to `127.0.0.1` and failing
      to connect to remote addresses.
      
      With the recent change to the way `bind` is handled, this presented
      other issues:
      
      * The default first bind address is '*' which is not a valid address.
      * We make no distinction between user-supplied config that is identical
      to the default, and the default config.
      
      This commit addresses both these issues by introducing an explicit
      configuration parameter to control the bind address on outgoing
      connections.
      f233c4c5
  14. 10 Jun, 2021 1 commit
    • Binbin's avatar
      Fixed some typos, add a spell check ci and others minor fix (#8890) · 0bfccc55
      Binbin authored
      This PR adds a spell checker CI action that will fail future PRs if they introduce typos and spelling mistakes.
      This spell checker is based on blacklist of common spelling mistakes, so it will not catch everything,
      but at least it is also unlikely to cause false positives.
      
      Besides that, the PR also fixes many spelling mistakes and types, not all are a result of the spell checker we use.
      
      Here's a summary of other changes:
      1. Scanned the entire source code and fixes all sorts of typos and spelling mistakes (including missing or extra spaces).
      2. Outdated function / variable / argument names in comments
      3. Fix outdated keyspace masks error log when we check `config.notify-keyspace-events` in loadServerConfigFromString.
      4. Trim the white space at the end of line in `module.c`. Check: https://github.com/redis/redis/pull/7751
      5. Some outdated https link URLs.
      6. Fix some outdated comment. Such as:
          - In README: about the rdb, we used to said create a `thread`, change to `process`
          - dbRandomKey function coment (about the dictGetRandomKey, change to dictGetFairRandomKey)
          - notifyKeyspaceEvent fucntion comment (add type arg)
          - Some others minor fix in comment (Most of them are incorrectly quoted by variable names)
      7. Modified the error log so that users can easily distinguish between TCP and TLS in `changeBindAddr`
      0bfccc55
  15. 02 Jun, 2021 1 commit
  16. 20 May, 2021 1 commit
  17. 19 May, 2021 1 commit
  18. 25 Apr, 2021 1 commit
  19. 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
  20. 16 Apr, 2021 1 commit
  21. 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
  22. 25 Mar, 2021 1 commit
  23. 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
  24. 21 Feb, 2021 1 commit
  25. 09 Feb, 2021 1 commit
  26. 28 Jan, 2021 1 commit
  27. 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
  28. 08 Jan, 2021 1 commit
  29. 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
  30. 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
  31. 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
  32. 17 Dec, 2020 1 commit
  33. 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
  34. 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
  35. 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
  36. 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