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  1. Spark
  2. SPARK-22062

BlockManager does not account for memory consumed by remote fetches

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Minor
    • Resolution: Fixed
    • Affects Version/s: 2.2.0
    • Fix Version/s: 2.3.0
    • Component/s: Block Manager
    • Labels:
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      Description

      We use Spark exclusively with StorageLevel.DiskOnly as our workloads are very sensitive to memory usage. Recently, we've spotted that the jobs sometimes OOM leaving lots of byte[] arrays on the heap. Upon further investigation, we've found that the arrays come from BlockManager.getRemoteBytes, which calls BlockTransferService.fetchBlockSync, which in its turn would allocate an on-heap ByteBuffer of the same size as the block (e.g. full partition), if the block was successfully retrieved over the network.

      This memory is not accounted towards Spark storage/execution memory and could potentially lead to OOM if BlockManager fetches too many partitions in parallel. I wonder if this is intentional behaviour, or in fact a bug?

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              • Assignee:
                jerryshao Saisai Shao
                Reporter:
                lebedev Sergei Lebedev
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                  Updated:
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