Commits on Oct 5, 2012
  1. Redis 2.6.0 RC8 (2.5.14)

    committed Oct 5, 2012
  2. Merge pull request #544 from dvirsky/2.6

    fixed install script to rewrite the default config
    committed Oct 5, 2012
  3. Hash function switched to murmurhash2.

    The previously used hash function, djbhash, is not secure against
    collision attacks even when the seed is randomized as there are simple
    ways to find seed-independent collisions.
    The new hash function appears to be safe (or much harder to exploit at
    least) in this case, and has better distribution.
    Better distribution does not always means that's better. For instance in
    a fast benchmark with "DEBUG POPULATE 1000000" I obtained the following
        1.6 seconds with djbhash
        2.0 seconds with murmurhash2
    This is due to the fact that djbhash will hash objects that follow the
    pattern `prefix:<id>` and where the id is numerically near, to near
    buckets. This improves the locality.
    However in other access patterns with keys that have no relation
    murmurhash2 has some (apparently minimal) speed advantage.
    On the other hand a better distribution should significantly
    improve the quality of the distribution of elements returned with
    dictGetRandomKey() that is used in SPOP, SRANDMEMBER, RANDOMKEY, and
    other commands.
    Everything considered, and under the suspect that this commit fixes a
    security issue in Redis, we are switching to the new hash function.
    If some serious speed regression will be found in the future we'll be able
    to step back easiliy.
    This commit fixes issue #663.
    committed Oct 3, 2012
  4. Warn when configured maxmemory value seems odd.

    This commit warns the user with a log at "warning" level if:
    1) After the server startup the maxmemory limit was found to be < 1MB.
    2) After a CONFIG SET command modifying the maxmemory setting the limit
    is set to a value that is smaller than the currently used memory.
    The behaviour of the Redis server is unmodified, and this wil not make
    the CONFIG SET command or a wrong configuration in redis.conf less
    likely to create problems, but at least this will make aware most users
    about a possbile error they committed without resorting to external
    However no warning is issued if, as a result of loading the AOF or RDB
    file, we are very near the maxmemory setting, or key eviction will be
    needed in order to go under the specified maxmemory setting. The reason
    is that in servers configured as a cache with an aggressive
    maxmemory-policy most of the times restarting the server will cause this
    condition to happen if persistence is not switched off.
    This fixes issue #429.
    committed Oct 5, 2012
Commits on Oct 4, 2012
  1. Force expire all timer events when system clock skew is detected.

    When system time changes back, the timer will not worker properly
    hence some core functionality of redis will stop working(e.g. replication,
    bgsave, etc). See issue #633 for details.
    The patch saves the previous time and when a system clock skew is detected,
    it will force expire all timers.
    Modiifed by @antirez: the previous time was moved into the eventLoop
    structure to make sure the library is still thread safe as long as you
    use different event loops into different threads (otherwise you need
    some synchronization). More comments added about the reasoning at the
    base of the patch, that's worth reporting here:
    /* If the system clock is moved to the future, and then set back to the
     * right value, time events may be delayed in a random way. Often this
     * means that scheduled operations will not be performed soon enough.
     * Here we try to detect system clock skews, and force all the time
     * events to be processed ASAP when this happens: the idea is that
     * processing events earlier is less dangerous than delaying them
     * indefinitely, and practice suggests it is. */
    jokea committed with Aug 30, 2012
  2. "Timeout receiving bulk data" error message modified.

    The new message now contains an hint about modifying the repl-timeout
    configuration directive if the problem persists.
    This should normally not be needed, because while the master generates
    the RDB file it makes sure to send newlines to the replication channel
    to prevent timeouts. However there are times when masters running on
    very slow systems can completely stop for seconds during the RDB saving
    process. In such a case enlarging the timeout value can fix the problem.
    See issue #695 for an example of this problem in an EC2 deployment.
    committed Oct 4, 2012
Commits on Oct 3, 2012
  1. "SORT by nosort" (skip sorting) respect sorted set ordering.

    When SORT is called with the option BY set to a string constant not
    inclduing the wildcard character "*", there is no way to sort the output
    so any ordering is valid. This allows the SORT internals to optimize its
    work and don't really sort the output at all.
    However it was odd that this option was not able to retain the natural
    order of a sorted set. This feature was requested by users multiple
    times as sometimes to call SORT with GET against sorted sets as a way to
    mass-fetch objects can be handy.
    This commit introduces two things:
    1) The ability of SORT to return sorted sets elements in their natural
    ordering when `BY nosort` is specified, accordingly to `DESC / ASC` options.
    2) The ability of SORT to optimize this case further if LIMIT is passed
    as well, avoiding to really fetch the whole sorted set, but directly
    obtaining the specified range.
    Because in this case the sorting is always deterministic, no
    post-sorting activity is performed when SORT is called from a Lua
    This commit fixes issue #98.
    committed Oct 3, 2012
Commits on Oct 1, 2012
  1. Revert "Scripting: redis.NIL to return nil bulk replies."

    This reverts commit e061d79.
    committed Oct 1, 2012
Commits on Sep 28, 2012
  1. Scripting: add helper functions redis.error_reply() and redis.status_…

    A previous commit introduced Redis.NIL. This commit adds similar helper
    functions to return tables with a single field set to the specified
    string so that instead of using 'return {err="My Error"}' it is possible
    to use a more idiomatic form:
        return redis.error_reply("My Error")
        return redis.status_reply("OK")
    committed Sep 28, 2012
  2. Scripting: redis.NIL to return nil bulk replies.

    Lua arrays can't contain nil elements (see for more information), so Lua scripts
    were not able to return a multi-bulk reply containing nil bulk
    elements inside.
    This commit introduces a special conversion: a table with just
    a "nilbulk" field set to a boolean value is converted by Redis as a nil
    bulk reply, but at the same time for Lua this type is not a "nil" so can
    be used inside Lua arrays.
    This type is also assigned to redis.NIL, so the following two forms
    are equivalent and will be able to return a nil bulk reply as second
    element of a three elements array:
        EVAL "return {1,redis.NIL,3}" 0
        EVAL "return {1,{nilbulk=true},3}" 0
    The result in redis-cli will be:
        1) (integer) 1
        2) (nil)
        3) (integer) 3
    committed Sep 28, 2012
Commits on Sep 27, 2012
  1. Final merge of Sentinel into 2.6.

    After cherry-picking Sentinel commits a few spurious issues remained
    about references to Redis Cluster that is not present in the 2.6 branch.
    committed Sep 27, 2012
  2. Sentinel: Support for AUTH.

    committed Sep 26, 2012
  3. Sentinel: reply -IDONTKNOW to get-master-addr-by-name on lack of info.

    If we don't have any clue about a master since it never replied to INFO
    so far, reply with an -IDONTKNOW error to SENTINEL
    get-master-addr-by-name requests.
    committed Sep 4, 2012
  4. Sentinel: more easy master redirection if master is a slave.

    Before this commit Sentienl used to redirect master ip/addr if the
    current instance reported to be a slave only if this was the first INFO
    output received, and the role was found to be slave.
    Now instead also if we find that the runid is different, and the
    reported role is slave, we also redirect to the reported master ip/addr.
    This unifies the behavior of Sentinel in the case of a reboot (where it
    will see the first INFO output with the wrong role and will perform the
    redirection), with the behavior of Sentinel in the case of a change in
    what it sees in the INFO output of the master.
    committed Sep 4, 2012
  5. Sentinel: do not crash against slaves not publishing the runid.

    Older versions of Redis (before 2.4.17) don't publish the runid field in
    INFO. This commit makes Sentinel able to handle that without crashing.
    committed Aug 30, 2012
  6. Sentinel: add Redis execution mode to INFO output.

    The new "redis_mode" field in the INFO output will show if Redis is
    running in standalone mode, cluster, or sentinel mode.
    committed Aug 29, 2012
  7. Sentinel: Sentinel-side support for slave priority.

    The slave priority that is now published by Redis in INFO output is
    now used by Sentinel in order to select the slave with minimum priority
    for promotion, and in order to consider slaves with priority set to 0 as
    not able to play the role of master (they will never be promoted by
    The "slave-priority" field is now one of the fileds that Sentinel
    publishes when describing an instance via the SENTINEL commands such as
    "SENTINEL slaves mastername".
    committed Aug 28, 2012
  8. Sentinel: suppress harmless warning by initializing 'table' to NULL.

    Note that the assertion guarantees that one of the if branches setting
    table is always entered.
    committed Aug 28, 2012
  9. Sentinel: send SCRIPT KILL on -BUSY reply and SDOWN instance.

    From the point of view of Redis an instance replying -BUSY is down,
    since it is effectively not able to reply to user requests. However
    a looping script is a recoverable condition in Redis if the script still
    did not performed any write to the dataset. In that case performing a
    fail over is not optimal, so Sentinel now tries to restore the normal server
    condition killing the script with a SCRIPT KILL command.
    If the script already performed some write before entering an infinite
    (or long enough to timeout) loop, SCRIPT KILL will not work and the
    fail over will be triggered anyway.
    committed Aug 24, 2012
  10. Sentinel: fixed a crash on script execution.

    The call to sentinelScheduleScriptExecution() lacked the final NULL
    argument to signal the end of arguments. This resulted into a crash.
    committed Aug 24, 2012
  11. Sentinel: SENTINEL FAILOVER command implemented.

    This command can be used in order to force a Sentinel instance to start
    a failover for the specified master, as leader, forcing the failover
    even if the master is up.
    The commit also adds some minor refactoring and other improvements to
    functions already implemented that make them able to work when the
    master is not in SDOWN condition. For instance slave selection
    assumed that we ask INFO every second to every slave, this is true
    only when the master is in SDOWN condition, so slave selection did not
    worked when the master was not in SDOWN condition.
    committed Aug 3, 2012
  12. Sentinel: client reconfiguration script execution.

    This commit adds support to optionally execute a script when one of the
    following events happen:
    * The failover starts (with a slave already promoted).
    * The failover ends.
    * The failover is aborted.
    The script is called with enough parameters (documented in the example
    sentinel.conf file) to provide information about the old and new ip:port
    pair of the master, the role of the sentinel (leader or observer) and
    the name of the master.
    The goal of the script is to inform clients of the configuration change
    in a way specific to the environment Sentinel is running, that can't be
    implemented in a genereal way inside Sentinel itself.
    committed Aug 2, 2012
  13. Sentinel: when leader in wait-start, sense another leader as race.

    When we are in wait start, if another leader (or any other external
    entity) turns a slave into a master, abort the failover, and detect it
    as an observer.
    Note that the wait-start state is mainly there for this reason but the
    abort was yet not implemented.
    This adds a new sentinel event -failover-abort-race.
    committed Jul 31, 2012
  14. Sentinel: abort failover when in wait-start if master is back.

    When we are a Leader Sentinel in wait-start state, starting with this
    commit the failover is aborted if the master returns online.
    This improves the way we handle a notable case of net split, that is the
    split between Sentinels and Redis servers, that will be a very common
    case of split becase Sentinels will often be installed in the client's
    network and servers can be in a differnt arm of the network.
    When Sentinels and Redis servers are isolated the master is in ODOWN
    condition since the Sentinels can agree about this state, however the
    failover does not start since there are no good slaves to promote (in
    this specific case all the slaves are unreachable).
    However when the split is resolved, Sentinels may sense the slave back
    a moment before they sense the master is back, so the failover may start
    without a good reason (since the master is actually working too).
    Now this condition is reversible, so the failover will be aborted
    immediately after if the master is detected to be working again, that
    is, not in SDOWN nor in ODOWN condition.
    committed Jul 31, 2012
  15. Sentinel: scripts execution engine improved.

    We no longer use a vanilla fork+execve but take a queue of jobs of
    scripts to execute, with retry on error, timeouts, and so forth.
    Currently this is used only for notifications but soon the ability to
    also call clients reconfiguration scripts will be added.
    committed Jul 27, 2012
  16. Include sys/wait.h to avoid compiler warning

    gcc warned about an implicit declaration of function 'wait3'.
    Including this header fixes this.
    badboy committed with Jul 28, 2012
  17. comment fix

    improve English a bit. :-)
    jzawodn committed with Jul 25, 2012