Uploaded image for project: 'Accumulo'
  1. Accumulo
  2. ACCUMULO-751

Support Wire Compatibility (between bugfix releases)

    XMLWordPrintableJSON

    Details

      Description

      With the advent of the HA NameNode in HDFS, the need for planned Hadoop outages has greatly diminished. I believe that Accumulo should follow suit and eventually allow for no-outage upgrades.

      To support this feature, we would require wire compatibility between different versions so that the cluster can continue to function in a mixed state. There are already contingencies for master fail-over and tservers to leave/join the cluster, so I think this is a natural extension of that code.

      To accomplish this for bugfix releases should be trivial. I think it is only necessary to remove (or relax) the version check that happens when a tserver attempts to join. There are rarely (never?) changes to the thrift protocol between bugfix releases, so theoretically a 1.4.1 tserver is already compatible with a 1.4.0 master and vice versa.

      To maintain compatibility in the face of thrift protocol changes is certainly a harder challenge, which might be best reserved for a separate ticket.

        Attachments

          Issue Links

            Activity

              People

              • Assignee:
                ctubbsii Christopher Tubbs
                Reporter:
                mdrob Mike Drob
              • Votes:
                1 Vote for this issue
                Watchers:
                3 Start watching this issue

                Dates

                • Created:
                  Updated:
                  Resolved: