1. 05 Aug, 2015 2 commits
    • antirez's avatar
      Make sure we re-emit SELECT after each new slave full sync setup. · 27c0ab23
      antirez authored
      In previous commits we moved the FULLRESYNC to the moment we start the
      BGSAVE, so that the offset we provide is the right one. However this
      also means that we need to re-emit the SELECT statement every time a new
      slave starts to accumulate the changes.
      
      To obtian this effect in a more clean way, the function that sends the
      FULLRESYNC reply was overloaded with a more important role of also doing
      this and chanigng the slave state. So it was renamed to
      replicationSetupSlaveForFullResync() to better reflect what it does now.
      27c0ab23
    • antirez's avatar
      PSYNC initial offset fix. · 9d297218
      antirez authored
      This commit attempts to fix a bug involving PSYNC and diskless
      replication (currently experimental) found by Yuval Inbar from Redis Labs
      and that was later found to have even more far reaching effects (the bug also
      exists when diskstore is off).
      
      The gist of the bug is that, a Redis master replies with +FULLRESYNC to
      a PSYNC attempt that fails and requires a full resynchronization.
      However, the baseline offset sent along with FULLRESYNC was always the
      current master replication offset. This is not ok, because there are
      many reasosn that may delay the RDB file creation. And... guess what,
      the master offset we communicate must be the one of the time the RDB
      was created. So for example:
      
      1) When the BGSAVE for replication is delayed since there is one
         already but is not good for replication.
      2) When the BGSAVE is not needed as we attach one currently ongoing.
      3) When because of diskless replication the BGSAVE is delayed.
      
      In all the above cases the PSYNC reply is wrong and the slave may
      reconnect later claiming to need a wrong offset: this may cause
      data curruption later.
      9d297218
  2. 17 Jul, 2015 1 commit
  3. 23 Dec, 2014 1 commit
    • antirez's avatar
      INFO loading stats: three fixes. · 1e8f1577
      antirez authored
      1. Server unxtime may remain not updated while loading AOF, so ETA is
      not updated correctly.
      
      2. Number of processed byte was not initialized.
      
      3. Possible division by zero condition (likely cause of issue #1932).
      1e8f1577
  4. 22 Dec, 2014 1 commit
  5. 29 Oct, 2014 12 commits
  6. 06 Oct, 2014 1 commit
  7. 26 Aug, 2014 3 commits
  8. 28 Jul, 2014 1 commit
  9. 18 Jul, 2014 3 commits
  10. 26 Jun, 2014 1 commit
  11. 12 May, 2014 2 commits
  12. 28 Apr, 2014 1 commit
    • antirez's avatar
      Process events with processEventsWhileBlocked() when blocked. · cdd2bd56
      antirez authored
      When we are blocked and a few events a processed from time to time, it
      is smarter to call the event handler a few times in order to handle the
      accept, read, write, close cycle of a client in a single pass, otherwise
      there is too much latency added for clients to receive a reply while the
      server is busy in some way (for example during the DB loading).
      cdd2bd56
  13. 24 Mar, 2014 1 commit
    • Matt Stancliff's avatar
      Fix data loss when save AOF/RDB with no free space · 65e04528
      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
      65e04528
  14. 13 Feb, 2014 1 commit
    • antirez's avatar
      Update cached time in rdbLoad() callback. · 3c1672da
      antirez authored
      server.unixtime and server.mstime are cached less precise timestamps
      that we use every time we don't need an accurate time representation and
      a syscall would be too slow for the number of calls we require.
      
      Such an example is the initialization and update process of the last
      interaction time with the client, that is used for timeouts.
      
      However rdbLoad() can take some time to load the DB, but at the same
      time it did not updated the time during DB loading. This resulted in the
      bug described in issue #1535, where in the replication process the slave
      loads the DB, creates the redisClient representation of its master, but
      the timestamp is so old that the master, under certain conditions, is
      sensed as already "timed out".
      
      Thanks to @yoav-steinberg and Redis Labs Inc for the bug report and
      analysis.
      3c1672da
  15. 10 Dec, 2013 2 commits
    • antirez's avatar
      Slaves heartbeats during sync improved. · 11120689
      antirez authored
      The previous fix for false positive timeout detected by master was not
      complete. There is another blocking stage while loading data for the
      first synchronization with the master, that is, flushing away the
      current data from the DB memory.
      
      This commit uses the newly introduced dict.c callback in order to make
      some incremental work (to send "\n" heartbeats to the master) while
      flushing the old data from memory.
      
      It is hard to write a regression test for this issue unfortunately. More
      support for debugging in the Redis core would be needed in terms of
      functionalities to simulate a slow DB loading / deletion.
      11120689
    • antirez's avatar
      7c531eb5
  16. 09 Dec, 2013 1 commit
    • antirez's avatar
      Slaves heartbeat while loading RDB files. · 27db38d0
      antirez authored
      Starting with Redis 2.8 masters are able to detect timed out slaves,
      while before 2.8 only slaves were able to detect a timed out master.
      
      Now that timeout detection is bi-directional the following problem
      happens as described "in the field" by issue #1449:
      
      1) Master and slave setup with big dataset.
      2) Slave performs the first synchronization, or a full sync
         after a failed partial resync.
      3) Master sends the RDB payload to the slave.
      4) Slave loads this payload.
      5) Master detects the slave as timed out since does not receive back the
         REPLCONF ACK acknowledges.
      
      Here the problem is that the master has no way to know how much the
      slave will take to load the RDB file in memory. The obvious solution is
      to use a greater replication timeout setting, but this is a shame since
      for the 0.1% of operation time we are forced to use a timeout that is
      not what is suited for 99.9% of operation time.
      
      This commit tries to fix this problem with a solution that is a bit of
      an hack, but that modifies little of the replication internals, in order
      to be back ported to 2.8 safely.
      
      During the RDB loading time, we send the master newlines to avoid
      being sensed as timed out. This is the same that the master already does
      while saving the RDB file to still signal its presence to the slave.
      
      The single newline is used because:
      
      1) It can't desync the protocol, as it is only transmitted all or
      nothing.
      2) It can be safely sent while we don't have a client structure for the
      master or in similar situations just with write(2).
      27db38d0
  17. 05 Dec, 2013 1 commit
  18. 07 Nov, 2013 1 commit
  19. 27 Aug, 2013 1 commit
  20. 20 Aug, 2013 1 commit
  21. 22 Jul, 2013 1 commit
    • antirez's avatar
      Introduction of a new string encoding: EMBSTR · 894eba07
      antirez authored
      Previously two string encodings were used for string objects:
      
      1) REDIS_ENCODING_RAW: a string object with obj->ptr pointing to an sds
      stirng.
      
      2) REDIS_ENCODING_INT: a string object where the obj->ptr void pointer
      is casted to a long.
      
      This commit introduces a experimental new encoding called
      REDIS_ENCODING_EMBSTR that implements an object represented by an sds
      string that is not modifiable but allocated in the same memory chunk as
      the robj structure itself.
      
      The chunk looks like the following:
      
      +--------------+-----------+------------+--------+----+
      | robj data... | robj->ptr | sds header | string | \0 |
      +--------------+-----+-----+------------+--------+----+
                           |                       ^
                           +-----------------------+
      
      The robj->ptr points to the contiguous sds string data, so the object
      can be manipulated with the same functions used to manipulate plan
      string objects, however we need just on malloc and one free in order to
      allocate or release this kind of objects. Moreover it has better cache
      locality.
      
      This new allocation strategy should benefit both the memory usage and
      the performances. A performance gain between 60 and 70% was observed
      during micro-benchmarks, however there is more work to do to evaluate
      the performance impact and the memory usage behavior.
      894eba07
  22. 16 Jul, 2013 1 commit