Details

    • Type: Improvement Improvement
    • Status: Resolved
    • Priority: Major Major
    • Resolution: Won't Fix
    • Affects Version/s: None
    • Fix Version/s: 0.90.0
    • Component/s: None
    • Labels:
      None

      Description

      Balancer is really basic; it just looks at counts of regions at the moment. It also as it currently works has loads of issues (See the linked issues) including a lack of testibility. This issue acts as the umbrella issue to collect all balancer improvements under.

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          Hide
          stack added a comment -

          Resolving. The new balancer addresses the issues raised here: i.e. "Load balancing is also currently too aggressive. It cannot run while a server crash is being processed. Region splits should not put two daughters back on the parent's RegionServer (often the balancer will come along soon after and move one of the just opened daughters ... sort ofhbase-2240). "

          This issue also wanted to be an umbrella issue for all to do w/ load balancing but given that above are addressed and most of the dependent issues, this issue adds nothing. Closing as 'wont fix'.

          Show
          stack added a comment - Resolving. The new balancer addresses the issues raised here: i.e. "Load balancing is also currently too aggressive. It cannot run while a server crash is being processed. Region splits should not put two daughters back on the parent's RegionServer (often the balancer will come along soon after and move one of the just opened daughters ... sort ofhbase-2240). " This issue also wanted to be an umbrella issue for all to do w/ load balancing but given that above are addressed and most of the dependent issues, this issue adds nothing. Closing as 'wont fix'.
          Hide
          stack added a comment -

          Here is a patch that breaks out load balancer and that starts in on writing unit test for the balancer code. Its incomplete and setting up the context for the balancer is awkward but not too bad.

          I gave up on this tack though for now – I was trying to repro hbase-2167 – because balancer is only one half of the balancing story. I'd have to break out the assignment code too to do a complete test of balance algorithm. Balancer figures out how many nodes can be offloaded from current regionserver, assignment code takes into consideration the rest of the cluster and rules whether to give this regionserver regions.

          Show
          stack added a comment - Here is a patch that breaks out load balancer and that starts in on writing unit test for the balancer code. Its incomplete and setting up the context for the balancer is awkward but not too bad. I gave up on this tack though for now – I was trying to repro hbase-2167 – because balancer is only one half of the balancing story. I'd have to break out the assignment code too to do a complete test of balance algorithm. Balancer figures out how many nodes can be offloaded from current regionserver, assignment code takes into consideration the rest of the cluster and rules whether to give this regionserver regions.
          Hide
          stack added a comment -

          Load balancing is also currently too aggressive. It cannot run while a server crash is being processed. Region splits should not put two daughters back on the parent's RegionServer (often the balancer will come along soon after and move one of the just opened daughters ... sort ofhbase-2240).

          Show
          stack added a comment - Load balancing is also currently too aggressive. It cannot run while a server crash is being processed. Region splits should not put two daughters back on the parent's RegionServer (often the balancer will come along soon after and move one of the just opened daughters ... sort ofhbase-2240).
          Hide
          stack added a comment -

          Linked to a few load-balancer issues.

          Show
          stack added a comment - Linked to a few load-balancer issues.

            People

            • Assignee:
              Unassigned
              Reporter:
              stack
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              Dates

              • Created:
                Updated:
                Resolved:

                Development