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  1. Hadoop YARN
  2. YARN-1902

Allocation of too many containers when a second request is done with the same resource capability

    Details

    • Type: Bug
    • Status: Open
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 2.2.0, 2.3.0, 2.4.0
    • Fix Version/s: None
    • Component/s: client
    • Labels:

      Description

      Regarding AMRMClientImpl

      Scenario 1:
      Given a ContainerRequest x with Resource y, when addContainerRequest is called z times with x, allocate is called and at least one of the z allocated containers is started, then if another addContainerRequest call is done and subsequently an allocate call to the RM, (z+1) containers will be allocated, where 1 container is expected.

      Scenario 2:
      No containers are started between the allocate calls.

      Analyzing debug logs of the AMRMClientImpl, I have found that indeed a (z+1) are requested in both scenarios, but that only in the second scenario, the correct behavior is observed.

      Looking at the implementation I have found that this (z+1) request is caused by the structure of the remoteRequestsTable. The consequence of Map<Resource, ResourceRequestInfo> is that ResourceRequestInfo does not hold any information about whether a request has been sent to the RM yet or not.

      There are workarounds for this, such as releasing the excess containers received.

      The solution implemented is to initialize a new ResourceRequest in ResourceRequestInfo when a request has been successfully sent to the RM.

      The patch includes a test in which scenario one is tested.

        Attachments

        1. YARN-1902.patch
          17 kB
          Sietse T. Au
        2. YARN-1902.v2.patch
          17 kB
          Sietse T. Au
        3. YARN-1902.v3.patch
          17 kB
          Sietse T. Au

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              • Assignee:
                stau-tudelft Sietse T. Au
                Reporter:
                stau-tudelft Sietse T. Au
              • Votes:
                2 Vote for this issue
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                31 Start watching this issue

                Dates

                • Created:
                  Updated: