1. 08 Jan, 2014 1 commit
    • antirez's avatar
      Don't send REPLCONF ACK to old masters. · 90a81b4e
      antirez authored
      Masters not understanding REPLCONF ACK will reply with errors to our
      requests causing a number of possible issues.
      
      This commit detects a global replication offest set to -1 at the end of
      the replication, and marks the client representing the master with the
      REDIS_PRE_PSYNC flag.
      
      Note that this flag was called REDIS_PRE_PSYNC_SLAVE but now it is just
      REDIS_PRE_PSYNC as it is used for both slaves and masters starting with
      this commit.
      
      This commit fixes issue #1488.
      90a81b4e
  2. 19 Dec, 2013 1 commit
  3. 11 Dec, 2013 1 commit
  4. 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
      dict.c: added optional callback to dictEmpty(). · 2eb781b3
      antirez authored
      Redis hash table implementation has many non-blocking features like
      incremental rehashing, however while deleting a large hash table there
      was no way to have a callback called to do some incremental work.
      
      This commit adds this support, as an optiona callback argument to
      dictEmpty() that is currently called at a fixed interval (one time every
      65k deletions).
      2eb781b3
  5. 04 Dec, 2013 1 commit
  6. 03 Dec, 2013 2 commits
  7. 29 Nov, 2013 1 commit
  8. 21 Nov, 2013 1 commit
  9. 19 Nov, 2013 2 commits
  10. 05 Nov, 2013 1 commit
    • antirez's avatar
      SCAN code refactored to parse cursor first. · ebcb6251
      antirez authored
      The previous implementation of SCAN parsed the cursor in the generic
      function implementing SCAN, SSCAN, HSCAN and ZSCAN.
      
      The actual higher-level command implementation only checked for empty
      keys and return ASAP in that case. The result was that inverting the
      arguments of, for instance, SSCAN for example and write:
      
          SSCAN 0 key
      
      Instead of
      
          SSCAN key 0
      
      Resulted into no error, since 0 is a non-existing key name very likely.
      Just the iterator returned no elements at all.
      
      In order to fix this issue the code was refactored to extract the
      function to parse the cursor and return the error. Every higher level
      command implementation now parses the cursor and later checks if the key
      exist or not.
      ebcb6251
  11. 28 Oct, 2013 3 commits
  12. 25 Oct, 2013 1 commit
  13. 09 Oct, 2013 2 commits
  14. 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
  15. 02 Oct, 2013 1 commit
  16. 30 Sep, 2013 1 commit
  17. 26 Sep, 2013 3 commits
  18. 25 Sep, 2013 1 commit
  19. 20 Sep, 2013 1 commit
    • 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
  20. 04 Sep, 2013 1 commit
    • antirez's avatar
      Cluster: free HANDSHAKE nodes after node_timeout. · 72587e6c
      antirez authored
      Handshake nodes should turn into normal nodes or be freed in a
      reasonable amount of time, otherwise they'll keep accumulating if the
      address they are associated with is not reachable for some reason.
      72587e6c
  21. 22 Aug, 2013 1 commit
  22. 12 Aug, 2013 1 commit
    • antirez's avatar
      Replication: better way to send a preamble before RDB payload. · 89ffba91
      antirez authored
      During the replication full resynchronization process, the RDB file is
      transfered from the master to the slave. However there is a short
      preamble to send, that is currently just the bulk payload length of the
      file in the usual Redis form $..length..<CR><LF>.
      
      This preamble used to be sent with a direct write call, assuming that
      there was alway room in the socket output buffer to hold the few bytes
      needed, however this does not scale in case we'll need to send more
      stuff, and is not very robust code in general.
      
      This commit introduces a more general mechanism to send a preamble up to
      2GB in size (the max length of an sds string) in a non blocking way.
      89ffba91
  23. 06 Aug, 2013 2 commits
  24. 05 Aug, 2013 1 commit
    • antirez's avatar
      Draft #1 of a new expired keys collection algorithm. · b09ea1bd
      antirez authored
      The main idea here is that when we are no longer to expire keys at the
      rate the are created, we can't block more in the normal expire cycle as
      this would result in too big latency spikes.
      
      For this reason the commit introduces a "fast" expire cycle that does
      not run for more than 1 millisecond but is called in the beforeSleep()
      hook of the event loop, so much more often, and with a frequency bound
      to the frequency of executed commnads.
      
      The fast expire cycle is only called when the standard expiration
      algorithm runs out of time, that is, consumed more than
      REDIS_EXPIRELOOKUPS_TIME_PERC of CPU in a given cycle without being able
      to take the number of already expired keys that are yet not collected
      to a number smaller than 25% of the number of keys.
      
      You can test this commit with different loads, but a simple way is to
      use the following:
      
      Extreme load with pipelining:
      
      redis-benchmark -r 100000000 -n 100000000  \
              -P 32 set ele:rand:000000000000 foo ex 2
      
      Remove the -P32 in order to avoid the pipelining for a more real-world
      load.
      
      In another terminal tab you can monitor the Redis behavior with:
      
      redis-cli -i 0.1 -r -1 info keyspace
      
      and
      
      redis-cli --latency-history
      
      Note: this commit will make Redis printing a lot of debug messages, it
      is not a good idea to use it in production.
      b09ea1bd
  25. 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
  26. 16 Jul, 2013 1 commit
  27. 12 Jul, 2013 2 commits
    • antirez's avatar
      SORT ALPHA: use collation instead of binary comparison. · cf1579a7
      antirez authored
      Note that we only do it when STORE is not used, otherwise we want an
      absolutely locale independent and binary safe sorting in order to ensure
      AOF / replication consistency.
      
      This is probably an unexpected behavior violating the least surprise
      rule, but there is currently no other simple / good alternative.
      cf1579a7
    • antirez's avatar
      Fixed compareStringObject() and introduced collateStringObject(). · 81e55ec0
      antirez authored
      compareStringObject was not always giving the same result when comparing
      two exact strings, but encoded as integers or as sds strings, since it
      switched to strcmp() when at least one of the strings were not sds
      encoded.
      
      For instance the two strings "123" and "123\x00456", where the first
      string was integer encoded, would result into the old implementation of
      compareStringObject() to return 0 as if the strings were equal, while
      instead the second string is "greater" than the first in a binary
      comparison.
      
      The same compasion, but with "123" encoded as sds string, would instead
      return a value < 0, as it is correct. It is not impossible that the
      above caused some obscure bug, since the comparison was not always
      deterministic, and compareStringObject() is used in the implementation
      of skiplists, hash tables, and so forth.
      
      At the same time, collateStringObject() was introduced by this commit, so
      that can be used by SORT command to return sorted strings usign
      collation instead of binary comparison. See next commit.
      81e55ec0
  28. 09 Jul, 2013 3 commits