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  1. Traffic Server
  2. TS-4485

MultiCache sync causes significant stalls to various in-flight requests

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 6.2.0, 7.0.0
    • Component/s: None
    • Labels:
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      Description

      MultiCache's sync to disk currently schedules the syncer task on the ET_NET thread that is holding the lock for the partition of hostdb. This is a bit unfortunate, as the syncer will actually call `msync` which means its calling a blocking write to disk. I'm seeing this cause some fairly large latency spikes (~100-300ms) on occasion-- even though the disk IO is completely available (since the ET_NET thread gets stalled the entire time, IO that needs to happen is also stalled).

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              • Assignee:
                jacksontj Thomas Jackson
                Reporter:
                jacksontj Thomas Jackson
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                • Created:
                  Updated:
                  Resolved: