Uploaded image for project: 'Cassandra'
  1. Cassandra
  2. CASSANDRA-6156

Poor resilience and recovery for bootstrapping node - "unable to fetch range"

    XMLWordPrintableJSON

Details

    • Improvement
    • Status: Resolved
    • Low
    • Resolution: Duplicate
    • None
    • None
    • None

    Description

      We have an 8 node cluster on 1.2.8 using vnodes. One of our nodes failed and we are having lots of trouble bootstrapping it back. On each attempt, bootstrapping eventually fails with a RuntimeException "Unable to fetch range". As far as we can tell, long GC pauses on the sender side cause heartbeat drops or delays, which leads the gossip controller to convict the connection and mark the sender dead. We've done significant GC tuning to minimize the duration of pauses and raised phi_convict to its max. It merely lets the bootstrap process take longer to fail.

      The inability to reliably add nodes significantly affects our ability to scale.

      We're not the only ones: http://stackoverflow.com/questions/19199349/cassandra-bootstrap-fails-with-unable-to-fetch-range

      What can we do in the immediate term to bring this node in? And what's the long term solution?

      One possible solution would be to allow bootstrapping to be an incremental process with individual transfers of vnode ownership instead of attempting to transfer the whole set of vnodes transactionally. (I assume that's what's happening now.) I don't know what would have to change on the gossip and token-aware client side to support this.

      Another solution would be to partition sstable files by vnode and allow transfer of those files directly with some sort of checkpointing of and incremental transfer of writes after the sstable is transferred.

      Attachments

        1. 007.log
          31 kB
          Keith Wright

        Issue Links

          Activity

            People

              Unassigned Unassigned
              akwan@nanigans.com Alyssa Kwan
              Votes:
              1 Vote for this issue
              Watchers:
              5 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: