1. 11 Mar, 2013 1 commit
    • antirez's avatar
      serverCron() frequency is now a runtime parameter (was REDIS_HZ). · aec5ea5d
      antirez authored
      REDIS_HZ is the frequency our serverCron() function is called with.
      A more frequent call to this function results into less latency when the
      server is trying to handle very expansive background operations like
      mass expires of a lot of keys at the same time.
      
      Redis 2.4 used to have an HZ of 10. This was good enough with almost
      every setup, but the incremental key expiration algorithm was working a
      bit better under *extreme* pressure when HZ was set to 100 for Redis
      2.6.
      
      However for most users a latency spike of 30 milliseconds when million
      of keys are expiring at the same time is acceptable, on the other hand a
      default HZ of 100 in Redis 2.6 was causing idle instances to use some
      CPU time compared to Redis 2.4. The CPU usage was in the order of 0.3%
      for an idle instance, however this is a shame as more energy is consumed
      by the server, if not important resources.
      
      This commit introduces HZ as a runtime parameter, that can be queried by
      INFO or CONFIG GET, and can be modified with CONFIG SET. At the same
      time the default frequency is set back to 10.
      
      In this way we default to a sane value of 10, but allows users to
      easily switch to values up to 500 for near real-time applications if
      needed and if they are willing to pay this small CPU usage penalty.
      aec5ea5d
  2. 19 Jan, 2013 1 commit
  3. 08 Nov, 2012 1 commit
  4. 24 Aug, 2012 1 commit
    • antirez's avatar
      Better Out of Memory handling. · 5de75120
      antirez authored
      The previous implementation of zmalloc.c was not able to handle out of
      memory in an application-specific way. It just logged an error on
      standard error, and aborted.
      
      The result was that in the case of an actual out of memory in Redis
      where malloc returned NULL (In Linux this actually happens under
      specific overcommit policy settings and/or with no or little swap
      configured) the error was not properly logged in the Redis log.
      
      This commit fixes this problem, fixing issue #509.
      Now the out of memory is properly reported in the Redis log and a stack
      trace is generated.
      
      The approach used is to provide a configurable out of memory handler
      to zmalloc (otherwise the default one logging the event on the
      standard output is used).
      5de75120
  5. 11 Jun, 2012 1 commit
    • antirez's avatar
      Dump ziplist hex value on failed assertion. · 0b8441c1
      antirez authored
      The ziplist -> hashtable conversion code is triggered every time an hash
      value must be promoted to a full hash table because the number or size of
      elements reached the threshold.
      
      If a problem in the ziplist causes the same field to be present
      multiple times, the assertion of successful addition of the element
      inside the hash table will fail, crashing server with a failed
      assertion, but providing little information about the problem.
      
      This code adds a new logging function to perform the hex dump of binary
      data, and makes sure that the ziplist -> hashtable conversion code uses
      this new logging facility to dump the content of the ziplist when the
      assertion fails.
      
      This change was originally made in order to investigate issue #547.
      0b8441c1
  6. 14 May, 2012 1 commit
    • antirez's avatar
      Impovements for: Redis timer, hashes rehashing, keys collection. · a8a981a8
      antirez authored
      A previous commit introduced REDIS_HZ define that changes the frequency
      of calls to the serverCron() Redis function. This commit improves
      different related things:
      
      1) Software watchdog: now the minimal period can be set according to
      REDIS_HZ. The minimal period is two times the timer period, that is:
      
          (1000/REDIS_HZ)*2 milliseconds
      
      2) The incremental rehashing is now performed in the expires dictionary
      as well.
      
      3) The activeExpireCycle() function was improved in different ways:
      
      - Now it checks if it already used too much time using microseconds
        instead of milliseconds for better precision.
      - The time limit is now calculated correctly, in the previous version
        the division was performed before of the multiplication resulting in
        a timelimit of 0 if HZ was big enough.
      - Databases with less than 1% of buckets fill in the hash table are
        skipped, because getting random keys is too expensive in this
        condition.
      
      4) tryResizeHashTables() is now called at every timer call, we need to
         match the number of calls we do to the expired keys colleciton cycle.
      
      5) REDIS_HZ was raised to 100.
      a8a981a8
  7. 27 Apr, 2012 1 commit
  8. 24 Apr, 2012 1 commit
    • antirez's avatar
      Fix and refactoring of code used to get registers on crash. · 38b60dea
      antirez authored
      This fixes compilation on FreeBSD (and possibly other systems) by
      not using ucontext_t at all if HAVE_BACKTRACE is not defined.
      Also the ifdefs to get the registers are modified to explicitly test for the
      operating system in the first level, and the arch in the second level
      of nesting.
      38b60dea
  9. 05 Apr, 2012 1 commit
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  11. 27 Mar, 2012 1 commit
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  17. 12 Jan, 2012 1 commit
  18. 21 Dec, 2011 2 commits
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  21. 12 Nov, 2011 1 commit
  22. 08 Nov, 2011 1 commit
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  25. 30 Jun, 2011 1 commit
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  29. 14 Mar, 2011 1 commit
  30. 09 Jan, 2011 3 commits