1. 16 Apr, 2014 1 commit
  2. 27 Mar, 2014 1 commit
  3. 25 Mar, 2014 13 commits
    • antirez's avatar
      Redis 2.8.8. · d2e59c27
      antirez authored
      d2e59c27
    • antirez's avatar
    • antirez's avatar
      adjustOpenFilesLimit() refactoring. · 3580bb48
      antirez authored
      In this commit:
      * Decrement steps are semantically differentiated from the reserved FDs.
        Previously both values were 32 but the meaning was different.
      * Make it clear that we save setrlimit errno.
      * Don't explicitly handle wrapping of 'f', but prevent it from
        happening.
      * Add comments to make the function flow more readable.
      
      This integrates PR #1630
      3580bb48
    • Matt Stancliff's avatar
      Fix potentially incorrect errno usage · c3510af1
      Matt Stancliff authored
      errno may be reset by the previous call to redisLog, so capture
      the original value for proper error reporting.
      c3510af1
    • Matt Stancliff's avatar
      Add REDIS_MIN_RESERVED_FDS define for open fds · 771f8ad0
      Matt Stancliff authored
      Also update the original REDIS_EVENTLOOP_FDSET_INCR to
      include REDIS_MIN_RESERVED_FDS. REDIS_EVENTLOOP_FDSET_INCR
      exists to make sure more than (maxclients+RESERVED) entries
      are allocated, but we can only guarantee that if we include
      the current value of REDIS_MIN_RESERVED_FDS as a minimum
      for the INCR size.
      771f8ad0
    • Matt Stancliff's avatar
      Fix infinite loop on startup if ulimit too low · 3ce742d1
      Matt Stancliff authored
      Fun fact: rlim_t is an unsigned long long on all platforms.
      
      Continually subtracting from a rlim_t makes it get smaller
      and smaller until it wraps, then you're up to 2^64-1.
      
      This was causing an infinite loop on Redis startup if
      your ulimit was extremely (almost comically) low.
      
      The case of (f > oldlimit) would never be met in a case like:
      
          f = 150
          while (f > 20) f -= 128
      
      Since f is unsigned, it can't go negative and would
      take on values of:
      
          Iteration 1: 150 - 128 => 22
          Iteration 2:  22 - 128 => 18446744073709551510
          Iterations 3-∞: ...
      
      To catch the wraparound, we use the previous value of f
      stored in limit.rlimit_cur.  If we subtract from f and
      get a larger number than the value it had previously,
      we print an error and exit since we don't have enough
      file descriptors to help the user at this point.
      
      Thanks to @bs3g for the inspiration to fix this problem.
      Patches existed from @bs3g at antirez#1227, but I needed to repair a few other
      parts of Redis simultaneously, so I didn't get a chance to use them.
      3ce742d1
    • Matt Stancliff's avatar
      Improve error handling around setting ulimits · b5958539
      Matt Stancliff authored
      The log messages about open file limits have always
      been slightly opaque and confusing.  Here's an attempt to
      fix their wording, detail, and meaning.  Users will have a
      better understanding of how to fix very common problems
      with these reworded messages.
      
      Also, we handle a new error case when maxclients becomes less
      than one, essentially rendering the server unusable.  We
      now exit on startup instead of leaving the user with a server
      unable to handle any connections.
      
      This fixes antirez#356 as well.
      b5958539
    • Matt Stancliff's avatar
      Replace magic 32 with REDIS_EVENTLOOP_FDSET_INCR · 6826af1b
      Matt Stancliff authored
      32 was the additional number of file descriptors Redis
      would reserve when managing a too-low ulimit.  The
      number 32 was in too many places statically, so now
      we use a macro instead that looks more appropriate.
      
      When Redis sets up the server event loop, it uses:
          server.maxclients+REDIS_EVENTLOOP_FDSET_INCR
      
      So, when reserving file descriptors, it makes sense to
      reserve at least REDIS_EVENTLOOP_FDSET_INCR FDs instead
      of only 32.  Currently, REDIS_EVENTLOOP_FDSET_INCR is
      set to 128 in redis.h.
      
      Also, I replaced the static 128 in the while f < old loop
      with REDIS_EVENTLOOP_FDSET_INCR as well, which results
      in no change since it was already 128.
      
      Impact: Users now need at least maxclients+128 as
      their open file limit instead of maxclients+32 to obtain
      actual "maxclients" number of clients.  Redis will carve
      the extra REDIS_EVENTLOOP_FDSET_INCR file descriptors it
      needs out of the "maxclients" range instead of failing
      to start (unless the local ulimit -n is too low to accomidate
      the request).
      6826af1b
    • Matt Stancliff's avatar
      Fix maxclients error handling · 611372fa
      Matt Stancliff authored
      Everywhere in the Redis code base, maxclients is treated
      as an int with (int)maxclients or `maxclients = atoi(source)`,
      so let's make maxclients an int.
      
      This fixes a bug where someone could specify a negative maxclients
      on startup and it would work (as well as set maxclients very high)
      because:
      
          unsigned int maxclients;
          char *update = "-300";
          maxclients = atoi(update);
          if (maxclients < 1) goto fail;
      
      But, (maxclients < 1) can only catch the case when maxclients
      is exactly 0.  maxclients happily sets itself to -300, which isn't
      -300, but rather 4294966996, which isn't < 1, so... everything
      "worked."
      
      maxclients config parsing checks for the case of < 1, but maxclients
      CONFIG SET parsing was checking for case of < 0 (allowing
      maxclients to be set to 0).  CONFIG SET parsing is now updated to
      match config parsing of < 1.
      
      It's tempting to add a MINIMUM_CLIENTS define, but... I didn't.
      
      These changes were inspired by antirez#356, but this doesn't
      fix that issue.
      611372fa
    • Matt Stancliff's avatar
      Sentinel: remove variable causing warning · 3bd32406
      Matt Stancliff authored
      GCC-4.9 warned about this, but clang didn't.
      
      This commit fixes warning:
      sentinel.c: In function 'sentinelReceiveHelloMessages':
      sentinel.c:2156:43: warning: variable 'master' set but not used [-Wunused-but-set-variable]
           sentinelRedisInstance *ri = c->data, *master;
      3bd32406
    • antirez's avatar
      Fixed undefined variable value with certain code paths. · 79349aff
      antirez authored
      In sentinelFlushConfig() fd could be undefined when the following if
      statement was true:
      
              if (rewrite_status == -1) goto werr;
      
      This could cause random file descriptors to get closed.
      79349aff
    • Matt Stancliff's avatar
      80dec5e4
    • Jan-Erik Rediger's avatar
      Small typo fixed · a2ec9a90
      Jan-Erik Rediger authored
      a2ec9a90
  4. 24 Mar, 2014 6 commits
    • Matt Stancliff's avatar
      Fix data loss when save AOF/RDB with no free space · 88c6c669
      Matt Stancliff authored
      Previously, the (!fp) would only catch lack of free space
      under OS X.  Linux waits to discover it can't write until
      it actually writes contents to disk.
      
      (fwrite() returns success even if the underlying file
      has no free space to write into.  All the errors
      only show up at flush/sync/close time.)
      
      Fixes antirez/redis#1604
      88c6c669
    • Jan-Erik Rediger's avatar
      Finally fix the `install_server.sh` script. · 6182dad3
      Jan-Erik Rediger authored
      Includes changes from a dozen bug reports and pull requests.
      Was tested on Ubuntu, Debian and CentOS.
      6182dad3
    • antirez's avatar
      Sample and cache RSS in serverCron(). · 4ebc7e37
      antirez authored
      Obtaining the RSS (Resident Set Size) info is slow in Linux and OSX.
      This slowed down the generation of the INFO 'memory' section.
      
      Since the RSS does not require to be a real-time measurement, we
      now sample it with server.hz frequency (10 times per second by default)
      and use this value both to show the INFO rss field and to compute the
      fragmentation ratio.
      
      Practically this does not make any difference for memory profiling of
      Redis but speeds up the INFO call significantly.
      4ebc7e37
    • antirez's avatar
      sdscatvprintf(): Try to use a static buffer. · 72257f4b
      antirez authored
      For small content the function now tries to use a static buffer to avoid
      a malloc/free cycle that is too costly when the function is used in the
      context of performance critical code path such as INFO output generation.
      
      This change was verified to have positive effects in the execution speed
      of the INFO command.
      72257f4b
    • antirez's avatar
      Cache uname() output across INFO calls. · 7054f2a0
      antirez authored
      Uname was profiled to be a slow syscall. It produces always the same
      output in the context of a single execution of Redis, so calling it at
      every INFO output generation does not make too much sense.
      
      The uname utsname structure was modified as a static variable. At the
      same time a static integer was added to check if we need to call uname
      the first time.
      7054f2a0
    • antirez's avatar
      sdscatvprintf(): guess buflen using format length. · 7a20f096
      antirez authored
      sdscatvprintf() uses a loop where it tries to output the formatted
      string in a buffer of the initial length, if there was not enough room,
      a buffer of doubled size is tried and so forth.
      
      The initial guess for the buffer length was very poor, an hardcoded
      "16". This caused the printf to be processed multiple times without a
      good reason. Given that printf functions are already not fast, the
      overhead was significant.
      
      The new heuristic is to use a buffer 4 times the length of the format
      buffer, and 32 as minimal size. This appears to be a good balance for
      typical uses of the function inside the Redis code base.
      
      This change improved INFO command performances 3 times.
      7a20f096
  5. 21 Mar, 2014 12 commits
    • antirez's avatar
      Use 24 bits for the lru object field and improve resolution. · 001775f5
      antirez authored
      There were 2 spare bits inside the Redis object structure that are now
      used in order to enlarge 4x the range of the LRU field.
      
      At the same time the resolution was improved from 10 to 1 second: this
      still provides 194 days before the LRU counter overflows (restarting from
      zero).
      
      This is not a problem since it only causes lack of eviction precision for
      objects not touched for a very long time, and the lack of precision is
      only temporary.
      001775f5
    • antirez's avatar
      Specify lruclock in redisServer structure via REDIS_LRU_BITS. · c68189a1
      antirez authored
      The padding field was totally useless: removed.
      c68189a1
    • antirez's avatar
      Set LRU parameters via REDIS_LRU_BITS define. · ff8c8187
      antirez authored
      ff8c8187
    • antirez's avatar
      Unify stats reset for CONFIG RESETSTAT / initServer(). · e3b71a1c
      antirez authored
      Now CONFIG RESETSTAT makes sure to reset all the fields, and in the
      future it will be simpler to avoid missing new fields.
      e3b71a1c
    • antirez's avatar
      Sentinel: sentinelRefreshInstanceInfo() minor refactoring. · 0937377a
      antirez authored
      Test sentinel.tilt condition on top and return if it is true.
      This allows to remove the check for the tilt condition in the remaining
      code paths of the function.
      0937377a
    • antirez's avatar
      686839b4
    • antirez's avatar
      6d0e408a
    • antirez's avatar
      ba2edc41
    • antirez's avatar
    • antirez's avatar
      Sentinel: down-after-milliseconds is not master-specific. · ffa8f479
      antirez authored
      addReplySentinelRedisInstance() modified so that this field is displayed
      for all the kind of instances: Sentinels, Masters, Slaves.
      ffa8f479
    • antirez's avatar
      Sentinel failure detection implementation improved. · 42091a79
      antirez authored
      Failure detection in Sentinel is ping-pong based. It used to work by
      remembering the last time a valid PONG reply was received, and checking
      if the reception time was too old compared to the current current time.
      
      PINGs were sent at a fixed interval of 1 second.
      
      This works in a decent way, but does not scale well when we want to set
      very small values of "down-after-milliseconds" (this is the node
      timeout basically).
      
      This commit reiplements the failure detection making a number of
      changes. Some changes are inspired to Redis Cluster failure detection
      code:
      
      * A new last_ping_time field is added in representation of instances.
        If non zero, we have an active ping that was sent at the specified
        time. When a valid reply to ping is received, the field is zeroed
        again.
      * last_ping_time is not reset when we reconnect the link or send a new
        ping, so from our point of view it represents the time we started
        waiting for the instance to reply to our pings without receiving a
        reply.
      * last_ping_time is now used in order to check if the instance is
        timed out. This means that we can have a node timeout of 100
        milliseconds and yet the system will work well since the new check is
        not bound to the period used to send pings.
      * Pings are now sent every second, or often if the value of
        down-after-milliseconds is less than one second. With a lower limit of
        10 HZ ping frequency.
      * Link reconnection code was improved. This is used in order to try to
        reconnect the link when we are at 50% of the node timeout without a
        valid reply received yet. However the old code triggered unnecessary
        reconnections when the node timeout was very small. Now that should be
        ok.
      
      The new code passes the tests but more testing is needed and more unit
      tests stressing the failure detector, so currently this is merged only
      in the unstable branch.
      42091a79
    • antirez's avatar
      Sentinel: use CLIENT SETNAME when connecting to Redis. · 38241c4b
      antirez authored
      This makes debugging / monitoring of Sentinels simpler since you can
      identify sentinels in CLIENT LIST output of Redis instances.
      38241c4b
  6. 14 Mar, 2014 4 commits
    • Matt Stancliff's avatar
      Fix segfault from accessing array out of bounds · 9de07558
      Matt Stancliff authored
      argc == 2; argv[2] == crash
      9de07558
    • antirez's avatar
      Sentinel: be safe under crash-recovery assumptions. · a31a0b43
      antirez authored
      Sentinel's main safety argument is that there are no two configurations
      for the same master with the same version (configuration epoch).
      
      For this to be true Sentinels require to be authorized by a majority.
      Additionally Sentinels require to do two important things:
      
      * Never vote again for the same epoch.
      * Never exchange an old vote for a fresh one.
      
      The first prerequisite, in a crash-recovery system model, requires to
      persist the master->leader_epoch on durable storage before to reply to
      messages. This was not the case.
      
      We also make sure to persist the current epoch in order to never reply
      to stale votes requests from other Sentinels, after a recovery.
      
      The configuration is persisted by making use of fsync(), this is
      considered in the context of this code a good enough guarantee that
      after a restart our durable state is restored, however this may not
      always be the case depending on the kind of hardware and operating
      system used.
      a31a0b43
    • antirez's avatar
      Sentinel: fake PUBLISH command to receive HELLO messages. · 6b0e36ff
      antirez authored
      Now the way HELLO messages are received is unified.
      Now it is no longer needed for Sentinels to converge to the higher
      configuration for a master to be able to chat via some Redis instance,
      the are able to directly exchanges configurations.
      
      Note that this commit does not include the (trivial) change needed to
      send HELLO messages to Sentinel instances as well, since for an error I
      committed the change in the previous commit that refactored hello
      messages processing into a separated function.
      6b0e36ff
    • antirez's avatar
  7. 13 Mar, 2014 1 commit
  8. 11 Mar, 2014 2 commits