1. 14 Mar, 2023 1 commit
    • Slava Koyfman's avatar
      Implementing the WAITAOF command (issue #10505) (#11713) · 9344f654
      Slava Koyfman authored
      
      
      Implementing the WAITAOF functionality which would allow the user to
      block until a specified number of Redises have fsynced all previous write
      commands to the AOF.
      
      Syntax: `WAITAOF <num_local> <num_replicas> <timeout>`
      Response: Array containing two elements: num_local, num_replicas
      num_local is always either 0 or 1 representing the local AOF on the master.
      num_replicas is the number of replicas that acknowledged the a replication
      offset of the last write being fsynced to the AOF.
      
      Returns an error when called on replicas, or when called with non-zero
      num_local on a master with AOF disabled, in all other cases the response
      just contains number of fsync copies.
      
      Main changes:
      * Added code to keep track of replication offsets that are confirmed to have
        been fsynced to disk.
      * Keep advancing master_repl_offset even when replication is disabled (and
        there's no replication backlog, only if there's an AOF enabled).
        This way we can use this command and it's mechanisms even when replication
        is disabled.
      * Extend REPLCONF ACK to `REPLCONF ACK <ofs> FACK <ofs>`, the FACK
        will be appended only if there's an AOF on the replica, and already ignored on
        old masters (thus backwards compatible)
      * WAIT now no longer wait for the replication offset after your last command, but
        rather the replication offset after your last write (or read command that caused
        propagation, e.g. lazy expiry).
      
      Unrelated changes:
      * WAIT command respects CLIENT_DENY_BLOCKING (not just CLIENT_MULTI)
      
      Implementation details:
      * Add an atomic var named `fsynced_reploff_pending` that's updated
        (usually by the bio thread) and later copied to the main `fsynced_reploff`
        variable (only if the AOF base file exists).
        I.e. during the initial AOF rewrite it will not be used as the fsynced offset
        since the AOF base is still missing.
      * Replace close+fsync bio job with new BIO_CLOSE_AOF (AOF specific)
        job that will also update fsync offset the field.
      * Handle all AOF jobs (BIO_CLOSE_AOF, BIO_AOF_FSYNC) in the same bio
        worker thread, to impose ordering on their execution. This solves a
        race condition where a job could set `fsynced_reploff_pending` to a higher
        value than another pending fsync job, resulting in indicating an offset
        for which parts of the data have not yet actually been fsynced.
        Imposing an ordering on the jobs guarantees that fsync jobs are executed
        in increasing order of replication offset.
      * Drain bio jobs when switching `appendfsync` to "always"
        This should prevent a write race between updates to `fsynced_reploff_pending`
        in the main thread (`flushAppendOnlyFile` when set to ALWAYS fsync), and
        those done in the bio thread.
      * Drain the pending fsync when starting over a new AOF to avoid race conditions
        with the previous AOF offsets overriding the new one (e.g. after switching to
        replicate from a new master).
      * Make sure to update the fsynced offset at the end of the initial AOF rewrite.
        a must in case there are no additional writes that trigger a periodic fsync,
        specifically for a replica that does a full sync.
      
      Limitations:
      It is possible to write a module and a Lua script that propagate to the AOF and doesn't
      propagate to the replication stream. see REDISMODULE_ARGV_NO_REPLICAS and luaRedisSetReplCommand.
      These features are incompatible with the WAITAOF command, and can result
      in two bad cases. The scenario is that the user executes command that only
      propagates to AOF, and then immediately
      issues a WAITAOF, and there's no further writes on the replication stream after that.
      1. if the the last thing that happened on the replication stream is a PING
        (which increased the replication offset but won't trigger an fsync on the replica),
        then the client would hang forever (will wait for an fack that the replica will never
        send sine it doesn't trigger any fsyncs).
      2. if the last thing that happened is a write command that got propagated properly,
        then WAITAOF will be released immediately, without waiting for an fsync (since
        the offset didn't change)
      
      Refactoring:
      * Plumbing to allow bio worker to handle multiple job types
        This introduces infrastructure necessary to allow BIO workers to
        not have a 1-1 mapping of worker to job-type. This allows in the
        future to assign multiple job types to a single worker, either as
        a performance/resource optimization, or as a way of enforcing
        ordering between specific classes of jobs.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      9344f654
  2. 13 Mar, 2023 1 commit
    • Binbin's avatar
      Fix tail->repl_offset update in feedReplicationBuffer (#11905) · 7997874f
      Binbin authored
      
      
      In #11666, we added a while loop and will split a big reply
      node to multiple nodes. The update of tail->repl_offset may
      be wrong. Like before #11666, we would have created at most
      one new reply node, and now we will create multiple nodes if
      it is a big reply node.
      
      Now we are creating more than one node, and the tail->repl_offset
      of all the nodes except the last one are incorrect. Because we
      update master_repl_offset at the beginning, and then use it to
      update the tail->repl_offset. This would have lead to an assertion
      during PSYNC, a test was added to validate that case.
      
      Besides that, the calculation of size was adjusted to fix
      tests that failed due to a combination of a very low backlog size,
      and some thresholds of that get violated because of the relatively
      high overhead of replBufBlock. So now if the backlog size / 16 is too
      small, we'll take PROTO_REPLY_CHUNK_BYTES instead.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      7997874f
  3. 12 Mar, 2023 3 commits
    • xbasel's avatar
      Large blocks of replica client output buffer could lead to psync loops and... · 7be7834e
      xbasel authored
      
      Large blocks of replica client output buffer could lead to psync loops and unnecessary memory usage (#11666)
      
      This can happen when a key almost equal or larger than the
      client output buffer limit of the replica is written.
      
      Example:
      1. DB is empty
      2. Backlog size is 1 MB
      3. Client out put buffer limit is 2 MB
      4. Client writes a 3 MB key
      5. The shared replication buffer will have a single node which contains
      the key written above, and it exceeds the backlog size.
      
      At this point the client output buffer usage calculation will report the
      replica buffer to be 3 MB (or more) even after sending all the data to
      the replica.
      The primary drops the replica connection for exceeding the limits,
      the replica reconnects and successfully executes partial sync but the
      primary will drop the connection again because the buffer usage is still
      3 MB. This happens over and over.
      
      To mitigate the problem, this fix limits the maximum size of a single
      backlog node to be (repl_backlog_size/16). This way a single node can't
      exceed the limits of the COB (the COB has to be larger than the
      backlog).
      It also means that if the backlog has some excessive data it can't trim,
      it would be at most about 6% overuse.
      
      other notes:
      1. a loop was added in feedReplicationBuffer which caused a massive LOC
        change due to indentation, the actual changes are just the `min(max` and the loop.
      3. an unrelated change in an existing test to speed up a server termination which took 10 seconds.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      7be7834e
    • Binbin's avatar
      redis-cli reads specified number of replies for UNSUBSCRIBE/PUNSUBSCRIBE/SUNSUBSCRIBE (#11047) · 08cd3bf2
      Binbin authored
      In unsubscribe related commands, we need to read the specified
      number of replies according to the number of parameters.
      
      These commands may return multiple RESP replies, and currently
      redis-cli only tries to read only one reply.
      
      Fixes #11046, this redis-cli bug seems to be there forever.
      Note that the [UN]SUBSCRIBE command response is a bit awkward
      see: https://github.com/redis/redis-doc/pull/2327
      08cd3bf2
    • Binbin's avatar
      Fix the bug that CLIENT REPLY OFF|SKIP cannot receive push notifications (#11875) · 416842e6
      Binbin authored
      This bug seems to be there forever, CLIENT REPLY OFF|SKIP will
      mark the client with CLIENT_REPLY_OFF or CLIENT_REPLY_SKIP flags.
      With these flags, prepareClientToWrite called by addReply* will
      return C_ERR directly. So the client can't receive the Pub/Sub
      messages and any other push notifications, e.g client side tracking.
      
      In this PR, we adding a CLIENT_PUSHING flag, disables the reply
      silencing flags. When adding push replies, set the flag, after the reply,
      clear the flag. Then add the flag check in prepareClientToWrite.
      
      Fixes #11874
      
      Note, the SUBSCRIBE command response is a bit awkward,
      see https://github.com/redis/redis-doc/pull/2327
      
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      416842e6
  4. 11 Mar, 2023 1 commit
    • guybe7's avatar
      Add reply_schema to command json files (internal for now) (#10273) · 4ba47d2d
      guybe7 authored
      Work in progress towards implementing a reply schema as part of COMMAND DOCS, see #9845
      Since ironing the details of the reply schema of each and every command can take a long time, we
      would like to merge this PR when the infrastructure is ready, and let this mature in the unstable branch.
      Meanwhile the changes of this PR are internal, they are part of the repo, but do not affect the produced build.
      
      ### Background
      In #9656 we add a lot of information about Redis commands, but we are missing information about the replies
      
      ### Motivation
      1. Documentation. This is the primary goal.
      2. It should be possible, based on the output of COMMAND, to be able to generate client code in typed
        languages. In order to do that, we need Redis to tell us, in detail, what each reply looks like.
      3. We would like to build a fuzzer that verifies the reply structure (for now we use the existing
        testsuite, see the "Testing" section)
      
      ### Schema
      The idea is to supply some sort of schema for the various replies of each command.
      The schema will describe the conceptual structure of the reply (for generated clients), as defined in RESP3.
      Note that the reply structure itself may change, depending on the arguments (e.g. `XINFO STREAM`, with
      and without the `FULL` modifier)
      We decided to use the standard json-schema (see https://json-schema.org/) as the reply-schema.
      
      Example for `BZPOPMIN`:
      ```
      "reply_schema": {
          "oneOf": [
              {
                  "description": "Timeout reached and no elements were popped.",
                  "type": "null"
              },
              {
                  "description": "The keyname, popped member, and its score.",
                  "type": "array",
                  "minItems": 3,
                  "maxItems": 3,
                  "items": [
                      {
                          "description": "Keyname",
                          "type": "string"
                      },
                      {
                          "description": "Member",
                          "type": "string"
                      },
                      {
                          "description": "Score",
                          "type": "number"
                      }
                  ]
              }
          ]
      }
      ```
      
      #### Notes
      1.  It is ok that some commands' reply structure depends on the arguments and it's the caller's responsibility
        to know which is the relevant one. this comes after looking at other request-reply systems like OpenAPI,
        where the reply schema can also be oneOf and the caller is responsible to know which schema is the relevant one.
      2. The reply schemas will describe RESP3 replies only. even though RESP3 is structured, we want to use reply
        schema for documentation (and possibly to create a fuzzer that validates the replies)
      3. For documentation, the description field will include an explanation of the scenario in which the reply is sent,
        including any relation to arguments. for example, for `ZRANGE`'s two schemas we will need to state that one
        is with `WITHSCORES` and the other is without.
      4. For documentation, there will be another optional field "notes" in which we will add a short description of
        the representation in RESP2, in case it's not trivial (RESP3's `ZRANGE`'s nested array vs. RESP2's flat
        array, for example)
      
      Given the above:
      1. We can generate the "return" section of all commands in [redis-doc](https://redis.io/commands/)
        (given that "description" and "notes" are comprehensive enough)
      2. We can generate a client in a strongly typed language (but the return type could be a conceptual
        `union` and the caller needs to know which schema is relevant). see the section below for RESP2 support.
      3. We can create a fuzzer for RESP3.
      
      ### Limitations (because we are using the standard json-schema)
      The problem is that Redis' replies are more diverse than what the json format allows. This means that,
      when we convert the reply to a json (in order to validate the schema against it), we lose information (see
      the "Testing" section below).
      The other option would have been to extend the standard json-schema (and json format) to include stuff
      like sets, bulk-strings, error-string, etc. but that would mean also extending the schema-validator - and that
      seemed like too much work, so we decided to compromise.
      
      Examples:
      1. We cannot tell the difference between an "array" and a "set"
      2. We cannot tell the difference between simple-string and bulk-string
      3. we cannot verify true uniqueness of items in commands like ZRANGE: json-schema doesn't cover the
        case of two identical members with different scores (e.g. `[["m1",6],["m1",7]]`) because `uniqueItems`
        compares (member,score) tuples and not just the member name. 
      
      ### Testing
      This commit includes some changes inside Redis in order to verify the schemas (existing and future ones)
      are indeed correct (i.e. describe the actual response of Redis).
      To do that, we added a debugging feature to Redis that causes it to produce a log of all the commands
      it executed and their replies.
      For that, Redis needs to be compiled with `-DLOG_REQ_RES` and run with
      `--reg-res-logfile <file> --client-default-resp 3` (the testsuite already does that if you run it with
      `--log-req-res --force-resp3`)
      You should run the testsuite with the above args (and `--dont-clean`) in order to make Redis generate
      `.reqres` files (same dir as the `stdout` files) which contain request-response pairs.
      These files are later on processed by `./utils/req-res-log-validator.py` which does:
      1. Goes over req-res files, generated by redis-servers, spawned by the testsuite (see logreqres.c)
      2. For each request-response pair, it validates the response against the request's reply_schema
        (obtained from the extended COMMAND DOCS)
      5. In order to get good coverage of the Redis commands, and all their different replies, we chose to use
        the existing redis test suite, rather than attempt to write a fuzzer.
      
      #### Notes about RESP2
      1. We will not be able to use the testing tool to verify RESP2 replies (we are ok with that, it's time to
        accept RESP3 as the future RESP)
      2. Since the majority of the test suite is using RESP2, and we want the server to reply with RESP3
        so that we can validate it, we will need to know how to convert the actual reply to the one expected.
         - number and boolean are always strings in RESP2 so the conversion is easy
         - objects (maps) are always a flat array in RESP2
         - others (nested array in RESP3's `ZRANGE` and others) will need some special per-command
           handling (so the client will not be totally auto-generated)
      
      Example for ZRANGE:
      ```
      "reply_schema": {
          "anyOf": [
              {
                  "description": "A list of member elements",
                  "type": "array",
                  "uniqueItems": true,
                  "items": {
                      "type": "string"
                  }
              },
              {
                  "description": "Members and their scores. Returned in case `WITHSCORES` was used.",
                  "notes": "In RESP2 this is returned as a flat array",
                  "type": "array",
                  "uniqueItems": true,
                  "items": {
                      "type": "array",
                      "minItems": 2,
                      "maxItems": 2,
                      "items": [
                          {
                              "description": "Member",
                              "type": "string"
                          },
                          {
                              "description": "Score",
                              "type": "number"
                          }
                      ]
                  }
              }
          ]
      }
      ```
      
      ### Other changes
      1. Some tests that behave differently depending on the RESP are now being tested for both RESP,
        regardless of the special log-req-res mode ("Pub/Sub PING" for example)
      2. Update the history field of CLIENT LIST
      3. Added basic tests for commands that were not covered at all by the testsuite
      
      ### TODO
      
      - [x] (maybe a different PR) add a "condition" field to anyOf/oneOf schemas that refers to args. e.g.
        when `SET` return NULL, the condition is `arguments.get||arguments.condition`, for `OK` the condition
        is `!arguments.get`, and for `string` the condition is `arguments.get` - https://github.com/redis/redis/issues/11896
      - [x] (maybe a different PR) also run `runtest-cluster` in the req-res logging mode
      - [x] add the new tests to GH actions (i.e. compile with `-DLOG_REQ_RES`, run the tests, and run the validator)
      - [x] (maybe a different PR) figure out a way to warn about (sub)schemas that are uncovered by the output
        of the tests - https://github.com/redis/redis/issues/11897
      - [x] (probably a separate PR) add all missing schemas
      - [x] check why "SDOWN is triggered by misconfigured instance replying with errors" fails with --log-req-res
      - [x] move the response transformers to their own file (run both regular, cluster, and sentinel tests - need to
        fight with the tcl including mechanism a bit)
      - [x] issue: module API - https://github.com/redis/redis/issues/11898
      - [x] (probably a separate PR): improve schemas: add `required` to `object`s - https://github.com/redis/redis/issues/11899
      
      Co-authored-by: default avatarOzan Tezcan <ozantezcan@gmail.com>
      Co-authored-by: default avatarHanna Fadida <hanna.fadida@redislabs.com>
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      Co-authored-by: default avatarShaya Potter <shaya@redislabs.com>
      4ba47d2d
  5. 09 Mar, 2023 1 commit
  6. 08 Mar, 2023 2 commits
    • Binbin's avatar
      Fix misleading error message in XREADGROUP (#11799) · 312654d5
      Binbin authored
      
      
      XREADGROUP can output a misleading error message regarding use of the $ special ID.
      
      Here is the example (with some newlines):
      ```
      redis> xreadgroup group workers worker1 count 1 streams mystream
      (error) ERR Unbalanced XREAD list of streams: for each stream key an ID or '$' must be specified.
      
      redis> xreadgroup group workers worker1 count 1 streams mystream $
      (error) ERR The $ ID is meaningless in the context of XREADGROUP: you want to read the history of this
      consumer by specifying a proper ID, or use the > ID to get new messages. The $ ID would just return an empty result set.
      
      redis> xreadgroup group workers worker1 count 1 streams mystream >
      1) 1) "mystream"
         2) 1) 1) "1673544607848-0"
               2) 1) "n"
                  2) "1"
      ```
      
      Note that XREADGROUP first returns an error with the following problems in it:
      - Command name in the error should be XREADGROUP not XREAD.
      - It recommends using $ as an option for a stream ID, then when you try this
        (see second XREADGROUP command above), it errors telling you that `$` doesn't
        make sense in this context even though the previous error message told you to use it
      
      Suggest that the command name be fixed in the first message, and the second part error
      message be amended not to talk about using `$` but `>` instead, this works, see the third
      and final XREADGROUP example above.
      
      Fixes #11730, commit message took from simonprickett.
      Co-authored-by: default avatarSimon Prickett <simon@redislabs.com>
      312654d5
    • ranshid's avatar
      Fix an issue when module decides to unblock a client which is blocked on keys (#11832) · 4988b928
      ranshid authored
      Currently (starting at #11012) When a module is blocked on keys it sets the
      CLIENT_PENDING_COMMAND flag.
      However in case the module decides to unblock the client not via the regular flow
      (eg timeout, key signal or CLIENT UNBLOCK command) it will attempt to reprocess the
      module command and potentially blocked again.
      
      This fix remove the CLIENT_PENDING_COMMAND flag in case blockedForKeys is
      issued from module context.
      4988b928
  7. 07 Mar, 2023 1 commit
    • Madelyn Olson's avatar
      Always compact nodes in stream listpacks after creating new nodes (#11885) · 2bb29e4a
      Madelyn Olson authored
      This change attempts to alleviate a minor memory usage degradation for Redis 6.2 and onwards when using rather large objects (~2k) in streams. Introduced in #6281, we pre-allocate the head nodes of a stream to be 4kb, to limit the amount of unnecessary initial reallocations that are done. However, if we only ever allocate one object because 2 objects exceeds the max_stream_entry_size, we never actually shrink it to fit the single item. This can lead to a lot of excessive memory usage. For smaller item sizes this becomes less of an issue, as the overhead decreases as the items become smaller in size.
      
      This commit also changes the MEMORY USAGE of streams, since it was reporting the lpBytes instead of the allocated size. This introduced an observability issue when diagnosing the memory issue, since Redis reported the same amount of used bytes pre and post change, even though the new implementation allocated more memory.
      2bb29e4a
  8. 05 Mar, 2023 1 commit
  9. 03 Mar, 2023 1 commit
  10. 28 Feb, 2023 4 commits
  11. 26 Feb, 2023 1 commit
    • ranshid's avatar
      assert in case resize output buffer will attempt to shrink too much (#11839) · 4972760b
      ranshid authored
      Currently there is no BUG. However during some internal code changes
      I found that it can happen (for example in case new code will not update
      the buf_peak) which can currently lead to memory overrun which is much
      harder to detect and root cause.
      
      Why did I please the assert here? The reason is to be able to have the
      buf_peak value without the risk of it being overriden by the peak_reset
      4972760b
  12. 23 Feb, 2023 2 commits
  13. 21 Feb, 2023 2 commits
    • Madelyn Olson's avatar
      Prevent Redis from crashing from key tracking invalidations (#11814) · dca5927a
      Madelyn Olson authored
      There is a built in limit to client side tracking keys, which when exceeded will invalidate keys. This occurs in two places, one in the server cron and other before executing a command. If it happens in the second scenario, the invalidations will be queued for later since current client is set. This queue is never drained if a command is not executed (through call) such as a multi-exec command getting queued. This results in a later server assert crashing.
      dca5927a
    • M Sazzadul Hoque's avatar
      Fix HELLO error message command syntax suggestion (#11809) · 4cc2b0dc
      M Sazzadul Hoque authored
      A simple HELLO command to a password protected Redis server replies
      with an error with another command suggestion. This omits protocol version
      from HELLO command arguments which causes another error.
      This PR adds the protocol version in the command suggestion.
      4cc2b0dc
  14. 20 Feb, 2023 1 commit
  15. 19 Feb, 2023 1 commit
  16. 16 Feb, 2023 3 commits
    • Oran Agra's avatar
      skip new page cache reclame unit test when running in valgrind (#11808) · 5b61b0dc
      Oran Agra authored
      the new test is incompatible with valgrind.
      added a new `--valgrind` argument to `redis-server tests` mode,
      which will cause that test to be skipped..
      5b61b0dc
    • Oran Agra's avatar
      Cleanup around script_caller, fix tracking of scripts and ACL logging for RM_Call (#11770) · 233abbbe
      Oran Agra authored
      * Make it clear that current_client is the root client that was called by
        external connection
      * add executing_client which is the client that runs the current command
        (can be a module or a script)
      * Remove script_caller that was used for commands that have CLIENT_SCRIPT
        to get the client that called the script. in most cases, that's the current_client,
        and in others (when being called from a module), it could be an intermediate
        client when we actually want the original one used by the external connection.
      
      bugfixes:
      * RM_Call with C flag should log ACL errors with the requested user rather than
        the one used by the original client, this also solves a crash when RM_Call is used
        with C flag from a detached thread safe context.
      * addACLLogEntry would have logged info about the script_caller, but in case the
        script was issued by a module command we actually want the current_client. the
        exception is when RM_Call is called from a timer event, in which case we don't
        have a current_client.
      
      behavior changes:
      * client side tracking for scripts now tracks the keys that are read by the script
        instead of the keys that are declared by the caller for EVAL
      
      other changes:
      * Log both current_client and executing_client in the crash log.
      * remove prepareLuaClient and resetLuaClient, being dead code that was forgotten.
      * remove scriptTimeSnapshot and snapshot_time and instead add cmd_time_snapshot
        that serves all commands and is reset only when execution nesting starts.
      * remove code to propagate CLIENT_FORCE_REPL from the executed command
        to the script caller since scripts aren't propagated anyway these days and anyway
        this flag wouldn't have had an effect since CLIENT_PREVENT_PROP is added by scriptResetRun.
      * fix a module GIL violation issue in afterSleep that was introduced in #10300 (unreleased)
      233abbbe
    • zhaozhao.zz's avatar
      a35e0837
  17. 14 Feb, 2023 2 commits
    • Wen Hui's avatar
      Update codes (#11804) · a7051845
      Wen Hui authored
      In this PR, we use function pointer *isPresent replace the variable "present" in auxFieldHandler, so that in the future, when we have more aux fields, we could decide if the aux field is displayed or not.
      a7051845
    • guybe7's avatar
      SCAN/RANDOMKEY and lazy-expire (#11788) · fd82bccd
      guybe7 authored
      Starting from Redis 7.0 (#9890) we started wrapping everything a command
       propagates with MULTI/EXEC. The problem is that both SCAN and RANDOMKEY can
      lazy-expire arbitrary keys (similar behavior to active-expire), and put DELs in a transaction.
      
      Fix: When these commands are called without a parent exec-unit (e.g. not in EVAL or
      MULTI) we avoid wrapping their DELs in a transaction (for the same reasons active-expire
      and eviction avoids a transaction)
      
      This PR adds a per-command flag that indicates that the command may touch arbitrary
      keys (not the ones in the arguments), and uses that flag to avoid the MULTI-EXEC.
      For now, this flag is internal, since we're considering other solutions for the future.
      
      Note for cluster mode: if SCAN/RANDOMKEY is inside EVAL/MULTI it can still cause the
      same situation (as it always did), but it won't cause a CROSSSLOT because replicas and AOF
      do not perform slot checks.
      The problem with the above is mainly for 3rd party ecosystem tools that propagate commands
      from master to master, or feed an AOF file with redis-cli into a master.
      This PR aims to fix the regression in redis 7.0, and we opened #11792 to try to handle the
      bigger problem with lazy expire better for another release.
      fd82bccd
  18. 12 Feb, 2023 1 commit
    • Tian's avatar
      Reclaim page cache of RDB file (#11248) · 7dae142a
      Tian authored
      # Background
      The RDB file is usually generated and used once and seldom used again, but the content would reside in page cache until OS evicts it. A potential problem is that once the free memory exhausts, the OS have to reclaim some memory from page cache or swap anonymous page out, which may result in a jitters to the Redis service.
      
      Supposing an exact scenario, a high-capacity machine hosts many redis instances, and we're upgrading the Redis together. The page cache in host machine increases as RDBs are generated. Once the free memory drop into low watermark(which is more likely to happen in older Linux kernel like 3.10, before [watermark_scale_factor](https://lore.kernel.org/lkml/1455813719-2395-1-git-send-email-hannes@cmpxchg.org/) is introduced, the `low watermark` is linear to `min watermark`, and there'is not too much buffer space for `kswapd` to be wake up to reclaim memory), a `direct reclaim` happens, which means the process would stall to wait for memory allocation.
      
      # What the PR does
      The PR introduces a capability to reclaim the cache when the RDB is operated. Generally there're two cases, read and write the RDB. For read it's a little messy to address the incremental reclaim, so the reclaim is done in one go in background after the load is finished to avoid blocking the work thread. For write, incremental reclaim amortizes the work of reclaim so no need to put it into background, and the peak watermark of cache can be reduced in this way.
      
      Two cases are addresses specially, replication and restart, for both of which the cache is leveraged to speed up the processing, so the reclaim is postponed to a right time. To do this, a flag is added to`rdbSave` and `rdbLoad` to control whether the cache need to be kept, with the default value false.
      
      # Something deserve noting
      1. Though `posix_fadvise` is the POSIX standard, but only few platform support it, e.g. Linux, FreeBSD 10.0.
      2. In Linux `posix_fadvise` only take effect on writeback-ed pages, so a `sync`(or `fsync`, `fdatasync`) is needed to flush the dirty page before `posix_fadvise` if we reclaim write cache.
      
      # About test
      A unit test is added to verify the effect of `posix_fadvise`.
      In integration test overall cache increase is checked, as well as the cache backed by RDB as a specific TCL test is executed in isolated Github action job.
      7dae142a
  19. 09 Feb, 2023 2 commits
    • Meir Shpilraien (Spielrein)'s avatar
      Match REDISMODULE_OPEN_KEY_* flags to LOOKUP_* flags (#11772) · 5c3938d5
      Meir Shpilraien (Spielrein) authored
      The PR adds support for the following flags on RedisModule_OpenKey:
      
      * REDISMODULE_OPEN_KEY_NONOTIFY - Don't trigger keyspace event on key misses.
      * REDISMODULE_OPEN_KEY_NOSTATS - Don't update keyspace hits/misses counters.
      * REDISMODULE_OPEN_KEY_NOEXPIRE - Avoid deleting lazy expired keys.
      * REDISMODULE_OPEN_KEY_NOEFFECTS - Avoid any effects from fetching the key
      
      In addition, added `RM_GetOpenKeyModesAll`, which returns the mask of all
      supported OpenKey modes. This allows the module to check, in runtime, which
      OpenKey modes are supported by the current Redis instance.
      5c3938d5
    • Binbin's avatar
      When DEBUG LOADAOF fails, return an error instead of exiting (#11790) · 66bed3f2
      Binbin authored
      Return an error when loadAppendOnlyFiles fails instead of
      exiting. DEBUF LOADAOF command is only meant to be used by
      the test suite, and only by tests that generated an AOF file
      first. So this change is ok (considering that the caller is
      likely to catch this error and die).
      
      This actually revert part of the code in #9012, and now
      DEBUG LOADAOF behaves the same as DEBUG RELOAD (returns an
      error when the load fails).
      
      Plus remove a `after 2000` in a test, which can save times (looks like copy paste error).
      66bed3f2
  20. 06 Feb, 2023 1 commit
  21. 02 Feb, 2023 3 commits
    • Roshan Khatri's avatar
      Added fields to ACL LOG error entries for precise time logging (#11477) · ac312954
      Roshan Khatri authored
      
      
      Added 3 fields to the ACL LOG - adds entry_id, timestamp_created and timestamp_last_updated, which updates similar existing log error entries. The pair - entry_id, timestamp_created is a unique identifier of this entry, in case the node dies and is restarted, it can detect that if it's a new series.
      
      The primary use case of Unique id is to uniquely identify the error messages and not to detect if the server has restarted.
      
      entry-id is the sequence number of the entry (starting at 0) since the server process started. Can also be used to check if items were "lost" if they fell between periods.
      timestamp-created is the unix-time in ms at the time the entry was first created.
      timestamp-last-updated is the unix-time in ms at the time the entry was last updated
      Time_created gives the absolute time which better accounts for network time as compared to time since. It can also be older than 60 secs and presently there is no field that can display the original time of creation once the error entry is updated.
      The reason of timestamp_last_updated field is that it provides a more precise value for the “last time” an error was seen where as, presently it is only in the 60 second period.
      Co-authored-by: default avatarMadelyn Olson <madelyneolson@gmail.com>
      ac312954
    • vanguard_space's avatar
      adding the ability to add streams to the pre-defined redis-benchmark tests (#11762) · 3b260149
      vanguard_space authored
      Added standard way to support xadd as one of the commands that can be run via redis-benchmarking tool
      3b260149
    • Harkrishn Patro's avatar
      Propagate message to a node only if the cluster link is healthy. (#11752) · fd397568
      Harkrishn Patro authored
      Currently while a sharded pubsub message publish tries to propagate the message across the cluster, a NULL check is missing for clusterLink. clusterLink could be NULL if the link is causing memory beyond the set threshold cluster-link-sendbuf-limit and server terminates the link.
      
      This change introduces two things:
      
      Avoids the engine crashes on the publishing node if a message is tried to be sent to a node and the link is NULL.
      Adds a debugging tool CLUSTERLINK KILL to terminate the clusterLink between two nodes.
      fd397568
  22. 01 Feb, 2023 1 commit
  23. 31 Jan, 2023 1 commit
    • uriyage's avatar
      Optimization: sdsRemoveFreeSpace to avoid realloc on noop (#11766) · 46393f98
      uriyage authored
      
      
      In #7875 (Redis 6.2), we changed the sds alloc to be the usable allocation
      size in order to:
      
      > reduce the need for realloc calls by making the sds implicitly take over
      the internal fragmentation
      
      This change was done most sds functions, excluding `sdsRemoveFreeSpace` and
      `sdsResize`, the reason is that in some places (e.g. clientsCronResizeQueryBuffer)
      we call sdsRemoveFreeSpace when we see excessive free space and want to trim it.
      so if we don't trim it exactly to size, the caller may still see excessive free space and
      call it again and again.
      
      However, this resulted in some excessive calls to realloc, even when there's no need
      and it's gonna be a no-op (e.g. when reducing 15 bytes allocation to 13).
      
      It turns out that a call for realloc with jemalloc can be expensive even if it ends up
      doing nothing, so this PR adds a check using `je_nallocx`, which is cheap to avoid
      the call for realloc.
      
      in addition to that this PR unifies sdsResize and sdsRemoveFreeSpace into common
      code. the difference between them was that sdsResize would avoid using SDS_TYPE_5,
      since it want to keep the string ready to be resized again, while sdsRemoveFreeSpace
      would permit using SDS_TYPE_5 and get an optimal memory consumption.
      now both methods take a `would_regrow` argument that makes it more explicit.
      
      the only actual impact of that is that in clientsCronResizeQueryBuffer we call both sdsResize
      and sdsRemoveFreeSpace for in different cases, and we now prevent the use of SDS_TYPE_5 in both.
      
      The new test that was added to cover this concern used to pass before this PR as well,
      this PR is just a performance optimization and cleanup.
      
      Benchmark:
      `redis-benchmark -c 100 -t set  -d 512 -P 10  -n  100000000`
      on i7-9850H with jemalloc, shows improvement from 1021k ops/sec to 1067k (average of 3 runs).
      some 4.5% improvement.
      Co-authored-by: default avatarOran Agra <oran@redislabs.com>
      46393f98
  24. 30 Jan, 2023 2 commits
    • Madelyn Olson's avatar
      Optimize the performance of cluster slots for non-continuous slots (#11745) · e74a1f3b
      Madelyn Olson authored
      This change improves the performance of cluster slots by removing the deferring lengths that are used. Deferring lengths are used in two contexts, the first is for determining the number of replicas that serve a slot (Added in 6.2 as part of a different performance improvement) and the second is for determining the extra networking options for each node (Added in 7.0). For continuous slots, (e.g. 0-8196) this improvement is very negligible, however it becomes more significant when slots are not continuous (e.g. 0 2 4 6 etc) which can happen in production for various users.
      
      The `cluster slots` command is deprecated in favor of `cluster shards`, but since most clients don't support the new command yet I think it's important to not degrade performance here.
      
      Benchmarking shows about 2x improvement, however I wasn't able to get a coherent TPS number since the benchmark process was being saturated long before Redis was, so had to run with multiple benchmarks and merge results. If needed I can add this to our memtier framework. Instead the next section shows the number of usec per call from the benchmark results, which shows significant improvement as well as having a more coherent response in the CoB.
      
      | | New Code | Old Code | % Improvements
      |----|----|----- |-----
      | Uniform slots| usec_per_call=10.46 | usec_per_call=11.03 | 5.7%
      | Worst case (Only even slots)| usec_per_call=963.80 | usec_per_call=2950.99 | 307%
      
      This change also removes some extra white space that I added a when making a code change for adding hostnames.
      e74a1f3b
    • Qu Chen's avatar
      Fix master client check in expireIfNeeded() for read only replica (#11761) · 6444214c
      Qu Chen authored
      Redis 7.0 introduced new logic in expireIfNeeded() where a read-only replica would never consider a key as expired when replicating commands from the master. See acf3495e. This was done by checking server.current_client with server.master. However, we should instead check for CLIENT_MASTER flag for this logic to be more robust and consistent with the rest of the Redis code base.
      6444214c
  25. 26 Jan, 2023 1 commit
    • Wen Hui's avatar
      update sentinel config condition (#11751) · cc97f4cf
      Wen Hui authored
      The command:
      sentinel config set option value
      and
      sentinel config get option
      
      They should include at least 4 arguments instead of 3,
      This PR fixes this issue.
      the only impact on the client is a different error message 
      cc97f4cf