1. 25 Mar, 2014 5 commits
    • 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
  2. 24 Mar, 2014 5 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
    • 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
  3. 21 Mar, 2014 9 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
    • 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
  4. 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
  5. 13 Mar, 2014 1 commit
  6. 11 Mar, 2014 4 commits
  7. 10 Mar, 2014 3 commits
    • antirez's avatar
      DEBUG ERROR implemented. · eb9e1526
      antirez authored
      The new "error" subcommand of the DEBUG command can reply with an user
      selected error, specified as its sole argument:
      
          DEBUG ERROR "LOADING please wait..."
      
      The error is generated just prefixing the command argument with a "-"
      character, and replacing newlines with spaces (since error replies can't
      include newlines).
      
      The goal of the command is to help in Client libraries unit tests by
      making simple to simulate a command call triggering a given error.
      eb9e1526
    • Matt Stancliff's avatar
      Fix return value check for anetTcpAccept · a6970570
      Matt Stancliff authored
      anetTcpAccept returns ANET_ERR, not AE_ERR.
      
      This isn't a physical error since both ANET_ERR
      and AE_ERR are -1, but better to be consistent.
      a6970570
    • antirez's avatar
  8. 05 Mar, 2014 8 commits
    • antirez's avatar
      Redis 2.8.7. · 464fef9b
      antirez authored
      464fef9b
    • antirez's avatar
      aab16ead
    • antirez's avatar
      Document why we update peak memory in INFO. · 55b8f6ec
      antirez authored
      55b8f6ec
    • Matt Stancliff's avatar
      Force INFO used_memory_peak to match peak memory · 647a2614
      Matt Stancliff authored
      used_memory_peak only updates in serverCron every server.hz,
      but Redis can use more memory and a user can request memory
      INFO before used_memory_peak gets updated in the next
      cron run.
      
      This patch updates used_memory_peak to the current
      memory usage if the current memory usage is higher
      than the recorded used_memory_peak value.
      
      (And it only calls zmalloc_used_memory() once instead of
      twice as it was doing before.)
      647a2614
    • antirez's avatar
      Sentinel test: Makefile target added. · 9c66cd91
      antirez authored
      9c66cd91
    • michael-grunder's avatar
      Improved bigkeys with progress, pipelining and summary · 69917929
      michael-grunder authored
      This commit reworks the redis-cli --bigkeys command to provide more
      information about our progress as well as output summary information
      when we're done.
      
       - We now show an approximate percentage completion as we go
       - Hiredis pipelining is used for TYPE and SIZE retreival
       - A summary of keyspace distribution and overall breakout at the end
      69917929
    • antirez's avatar
      Sentinel: more aggressive failover start desynchronization. · 1606978a
      antirez authored
      Sentinel needs to avoid split brain conditions due to multiple sentinels
      trying to get voted at the exact same time.
      
      So far some desynchronization was provided by fluctuating server.hz,
      that is the frequency of the timer function call. However the
      desynchonization provided in this way was not enough when using many
      Sentinel instances, especially when a large quorum value is used in
      order to force a greater degree of agreement (more than N/2+1).
      
      It was verified that it was likely to trigger a split brain
      condition, forcing the system to try again after a timeout.
      Usually the system will succeed after a few retries, but this is not
      optimal.
      
      This commit desynchronizes instances in a more effective way to make it
      likely that the first attempt will be successful.
      1606978a
    • antirez's avatar
      62001919
  9. 28 Feb, 2014 1 commit