[jira] [Created] (HELIX-151) Auto rebalance doesn't assign some replicas when other nodes could make room

["Kanak Biscuitwala (JIRA)" <ji...@apache.org>]

Kanak Biscuitwala created HELIX-151:
---------------------------------------

             Summary: Auto rebalance doesn't assign some replicas when other nodes could make room
                 Key: HELIX-151
                 URL: https://issues.apache.org/jira/browse/HELIX-151
             Project: Apache Helix
          Issue Type: Bug
          Components: helix-core
            Reporter: Kanak Biscuitwala
            Assignee: Kanak Biscuitwala
            Priority: Minor


The current auto-rebalancer tries to evenly distribute replicas across nodes by dividing the number of replicas by number of nodes, and then assigning the floor as a capacity to some nodes and the ceiling as a capacity to other nodes. Right now, nodes 0..k are assigned the ceiling and k+1..n are assigned the floor. Given existing assignments, an orphaned partition could be assigned to a node in the second set if that node had an extra slot, and there's at least one node in the first set with available capacity, then the latter node should be able to "donate" a unit of capacity to the former node.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira