1. 01 Apr, 2015 2 commits
    • antirez's avatar
      Net: improve prepareClientToWrite() error handling and comments. · 60a28fad
      antirez authored
      When we fail to setup the write handler it does not make sense to take
      the client around, it is missing writes: whatever is a client or a slave
      anyway the connection should terminated ASAP.
      
      Moreover what the function does exactly with its return value, and in
      which case the write handler is installed on the socket, was not clear,
      so the functions comment are improved to make the goals of the function
      more obvious.
      
      Also related to #2485.
      60a28fad
    • Oran Agra's avatar
      fixes to diskless replication. · aa67aec8
      Oran Agra authored
      master was closing the connection if the RDB transfer took long time.
      and also sent PINGs to the slave before it got the initial ACK, in which case the slave wouldn't be able to find the EOF marker.
      aa67aec8
  2. 24 Mar, 2015 1 commit
    • antirez's avatar
      Replication: disconnect blocked clients when switching to slave role. · 7e78ab4b
      antirez authored
      Bug as old as Redis and blocking operations. It's hard to trigger since
      only happens on instance role switch, but the results are quite bad
      since an inconsistency between master and slave is created.
      
      How to trigger the bug is a good description of the bug itself.
      
      1. Client does "BLPOP mylist 0" in master.
      2. Master is turned into slave, that replicates from New-Master.
      3. Client does "LPUSH mylist foo" in New-Master.
      4. New-Master propagates write to slave.
      5. Slave receives the LPUSH, the blocked client get served.
      
      Now Master "mylist" key has "foo", Slave "mylist" key is empty.
      
      Highlights:
      
      * At step "2" above, the client remains attached, basically escaping any
        check performed during command dispatch: read only slave, in that case.
      * At step "5" the slave (that was the master), serves the blocked client
        consuming a list element, which is not consumed on the master side.
      
      This scenario is technically likely to happen during failovers, however
      since Redis Sentinel already disconnects clients using the CLIENT
      command when changing the role of the instance, the bug is avoided in
      Sentinel deployments.
      
      Closes #2473.
      7e78ab4b
  3. 03 Dec, 2014 1 commit
    • antirez's avatar
      Network bandwidth tracking + refactoring. · 8a67e5d4
      antirez authored
      Track bandwidth used by clients and replication (but diskless
      replication is not tracked since the actual transfer happens in the
      child process).
      
      This includes a refactoring that makes tracking new instantaneous
      metrics simpler.
      8a67e5d4
  4. 12 Nov, 2014 2 commits
    • antirez's avatar
      Diskless SYNC: fix RDB EOF detection. · 90911905
      antirez authored
      RDB EOF detection was relying on the final part of the RDB transfer to
      be a magic 40 bytes EOF marker. However as the slave is put online
      immediately, and because of sockets timeouts, the replication stream is
      actually contiguous with the RDB file.
      
      This means that to detect the EOF correctly we should either:
      
      1) Scan all the stream searching for the mark. Sucks CPU-wise.
      2) Start to send the replication stream only after an acknowledge.
      3) Implement a proper chunked encoding.
      
      For now solution "2" was picked, so the master does not start to send
      ASAP the stream of commands in the case of diskless replication. We wait
      for the first REPLCONF ACK command from the slave, that certifies us
      that the slave correctly loaded the RDB file and is ready to get more
      data.
      90911905
    • antirez's avatar
  5. 31 Oct, 2014 1 commit
    • Matt Stancliff's avatar
      Networking: add more outbound IP binding fixes · f1a6f780
      Matt Stancliff authored
      Same as the original bind fixes (we just missed these the
      first time around).
      
      This helps Redis not automatically send
      connections from the first IP on an interface if we are bound
      to a specific IP address (e.g. with multiple IP aliases on one
      interface, you want to send from _your_ IP, not from the first IP
      on the interface).
      f1a6f780
  6. 29 Oct, 2014 20 commits
  7. 06 Oct, 2014 2 commits
  8. 26 Jun, 2014 1 commit
  9. 21 Jun, 2014 3 commits
  10. 28 Apr, 2014 1 commit
    • antirez's avatar
      CLIENT LIST speedup via peerid caching + smart allocation. · a11ae385
      antirez authored
      This commit adds peer ID caching in the client structure plus an API
      change and the use of sdsMakeRoomFor() in order to improve the
      reallocation pattern to generate the CLIENT LIST output.
      
      Both the changes account for a very significant speedup.
      a11ae385
  11. 05 Feb, 2014 1 commit
    • antirez's avatar
      Check for EAGAIN in sendBulkToSlave(). · 970de3e9
      antirez authored
      Sometime an osx master with a Linux server over a slow link caused
      a strange error where osx called the writable function for
      the socket but actually apparently there was no room in the socket
      buffer to accept the write: write(2) call returned an EAGAIN error,
      that was not checked, so we considered write(2) == 0 always as a connection
      reset, which was unfortunate since the bulk transfer has to start again.
      
      Also more errors are logged with the WARNING level in the same code path
      now.
      970de3e9
  12. 29 Jan, 2014 1 commit
    • antirez's avatar
      Cluster: function clusterGetSlaveRank() added. · 6f540320
      antirez authored
      Return the number of slaves for the same master having a better
      replication offset of the current slave, that is, the slave "rank" used
      to pick a delay before the request for election.
      6f540320
  13. 17 Jan, 2014 1 commit
  14. 08 Jan, 2014 2 commits
    • 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
    • antirez's avatar
      3f92e056
  15. 22 Dec, 2013 1 commit
    • antirez's avatar
      Make new masters inherit replication offsets. · 94e8c9e7
      antirez authored
      Currently replication offsets could be used into a limited way in order
      to understand, out of a set of slaves, what is the one with the most
      updated data. For example this comparison is possible of N slaves
      were replicating all with the same master.
      
      However the replication offset was not transferred from master to slaves
      (that are later promoted as masters) in any way, so for instance if
      there were three instances A, B, C, with A master and B and C
      replication from A, the following could happen:
      
      C disconnects from A.
      B is turned into master.
      A is switched to master of B.
      B receives some write.
      
      In this context there was no way to compare the offset of A and C,
      because B would use its own local master replication offset as
      replication offset to initialize the replication with A.
      
      With this commit what happens is that when B is turned into master it
      inherits the replication offset from A, making A and C comparable.
      In the above case assuming no inconsistencies are created during the
      disconnection and failover process, A will show to have a replication
      offset greater than C.
      
      Note that this does not mean offsets are always comparable to understand
      what is, in a set of instances, since in more complex examples the
      replica with the higher replication offset could be partitioned away
      when picking the instance to elect as new master. However this in
      general improves the ability of a system to try to pick a good replica
      to promote to master.
      94e8c9e7