1. 03 Oct, 2013 1 commit
    • antirez's avatar
      Cluster: new clusterDoBeforeSleep() API. · 7afc0dd5
      antirez authored
      The new API is able to remember operations to perform before returning
      to the event loop, such as checking if there is the failover quorum for
      a slave, save and fsync the configuraiton file, and so forth.
      
      Because this operations are performed before returning on the event
      loop we are sure that messages that are sent in the same event loop run
      will be delivered *after* the configuration is already saved, that is a
      requirement sometimes. For instance we want to publish a new epoch only
      when it is already stored in nodes.conf in order to avoid returning back
      in the logical clock when a node is restarted.
      
      This new API provides a big performance advantage compared to saving and
      possibly fsyncing the configuration file multiple times in the same
      event loop run, especially in the case of big clusters with tens or
      hundreds of nodes.
      7afc0dd5
  2. 02 Oct, 2013 3 commits
  3. 01 Oct, 2013 2 commits
  4. 30 Sep, 2013 6 commits
  5. 27 Sep, 2013 1 commit
  6. 26 Sep, 2013 4 commits
  7. 25 Sep, 2013 4 commits
  8. 20 Sep, 2013 2 commits
    • antirez's avatar
      Cluster: PFAIL -> FAIL transition allowed for slaves. · 3c9bb875
      antirez authored
      First change: now there is no need to be a master in order to detect a
      failure, however the majority of masters signaling PFAIL or FAIL is needed.
      
      This change is important because it allows slaves rejoining the cluster
      after a partition to sense the FAIL condition so that eventually all the
      nodes agree on failures.
      3c9bb875
    • antirez's avatar
      Cluster: added time field in cluster bus messages. · 925ea9f8
      antirez authored
      The time is sent in requests, and copied back in reply packets.
      This way the receiver can compare the time field in a reply with its
      local clock and check the age of the request associated with this reply.
      
      This is an easy way to discard delayed replies. Note that only a clock
      is used here, that is the one of the node sending the packet. The
      receiver only copies the field back into the reply, so no
      synchronization is needed between clocks of different hosts.
      925ea9f8
  9. 04 Sep, 2013 5 commits
  10. 03 Sep, 2013 3 commits
  11. 26 Aug, 2013 1 commit
    • antirez's avatar
      Don't update node pong time via gossip. · 303dde37
      antirez authored
      This feature was implemented in the initial days of the Redis Cluster
      implementaiton but is not a good idea at all.
      
      1) It depends on clocks to be synchronized, that is already very bad.
      2) Moreover it adds a bug where the pong time is updated via gossip so
      no new PING is ever sent by the current node, with the effect of no PONG
      received, no update of tables, no clearing of PFAIL flag.
      
      In general to trust other nodes about the reachability of other nodes is
      a broken distributed programming model.
      303dde37
  12. 22 Aug, 2013 4 commits
  13. 21 Aug, 2013 1 commit
  14. 24 Jul, 2013 1 commit
    • antirez's avatar
      sdsrange() does not need to return a value. · 6ea8e094
      antirez authored
      Actaully the string is modified in-place and a reallocation is never
      needed, so there is no need to return the new sds string pointer as
      return value of the function, that is now just "void".
      6ea8e094
  15. 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
  16. 09 Jul, 2013 1 commit