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  1. Core Server
  2. SERVER-19189

Improve performance under high number of threads with WT

    Details

    • Type: Task
    • Status: Closed
    • Priority: Major - P3
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.0.5, 3.1.6
    • Component/s: WiredTiger
    • Labels:
      None
    • Backwards Compatibility:
      Fully Compatible
    • Backport Completed:
    • Epic Link:
    • Sprint:
      Quint Iteration 6

      Issue Links

        Activity

        Hide
        michael.cahill Michael Cahill added a comment -
        Show
        michael.cahill Michael Cahill added a comment - Testing the 3.0 backport here: https://evergreen.mongodb.com/version/559f4aa23ff122536500011c_0
        Hide
        michael.cahill Michael Cahill added a comment -

        btw Martin Bligh, the WT_SESSION::reset call is in MongoDB master, we can try having releaseSession call that on the cached session in the Client in your patch?

        Show
        michael.cahill Michael Cahill added a comment - btw Martin Bligh , the WT_SESSION::reset call is in MongoDB master, we can try having releaseSession call that on the cached session in the Client in your patch?
        Hide
        xgen-internal-githook Githook User added a comment -

        Author:

        {u'username': u'martinbligh', u'name': u'Martin Bligh', u'email': u'mbligh@mongodb.com'}

        Message: SERVER-19189: dont check sessions is empty outside of the lock

        Technically it's illegal to check this outside the lock, though it's heuristic
        However, it's the unlikely case and we end up doing the work twice, so
        it seems cleaner to remove it and just do it inside the lock. Checked
        perf, no measurable difference

        (cherry picked from commit 90f72ea0b819335e55a6ddd147d5c8d4afa3c988)
        Branch: v3.0
        https://github.com/mongodb/mongo/commit/60802d74b1b8df7e194ecc028c8d73e134de791b

        Show
        xgen-internal-githook Githook User added a comment - Author: {u'username': u'martinbligh', u'name': u'Martin Bligh', u'email': u'mbligh@mongodb.com'} Message: SERVER-19189 : dont check sessions is empty outside of the lock Technically it's illegal to check this outside the lock, though it's heuristic However, it's the unlikely case and we end up doing the work twice, so it seems cleaner to remove it and just do it inside the lock. Checked perf, no measurable difference (cherry picked from commit 90f72ea0b819335e55a6ddd147d5c8d4afa3c988) Branch: v3.0 https://github.com/mongodb/mongo/commit/60802d74b1b8df7e194ecc028c8d73e134de791b
        Hide
        xgen-internal-githook Githook User added a comment -

        Author:

        {u'username': u'martinbligh', u'name': u'Martin Bligh', u'email': u'mbligh@mongodb.com'}

        Message: SERVER-19189: Checking epoch outside of the lock is racy

        can race with epoch++ and end up with us putting an old
        epoch session back in the cache.

        (cherry picked from commit 2256dfa40676c48788265d241f7fa18ac0d0b322)
        Branch: v3.0
        https://github.com/mongodb/mongo/commit/9c4fe15f5580c8768e593fff5de8de9dda8fb7d0

        Show
        xgen-internal-githook Githook User added a comment - Author: {u'username': u'martinbligh', u'name': u'Martin Bligh', u'email': u'mbligh@mongodb.com'} Message: SERVER-19189 : Checking epoch outside of the lock is racy can race with epoch++ and end up with us putting an old epoch session back in the cache. (cherry picked from commit 2256dfa40676c48788265d241f7fa18ac0d0b322) Branch: v3.0 https://github.com/mongodb/mongo/commit/9c4fe15f5580c8768e593fff5de8de9dda8fb7d0
        Hide
        xgen-internal-githook Githook User added a comment -

        Author:

        {u'username': u'martinbligh', u'name': u'Martin Bligh', u'email': u'mbligh@mongodb.com'}

        Message: SERVER-19189: Remove counters from WT session cache

        (cherry picked from commit 47b6b1a8fd60b0365f72c0550269c0dc0322acfd)
        Branch: v3.0
        https://github.com/mongodb/mongo/commit/604d172a093c041a53ceedbefb346f300b7b24c5

        Show
        xgen-internal-githook Githook User added a comment - Author: {u'username': u'martinbligh', u'name': u'Martin Bligh', u'email': u'mbligh@mongodb.com'} Message: SERVER-19189 : Remove counters from WT session cache (cherry picked from commit 47b6b1a8fd60b0365f72c0550269c0dc0322acfd) Branch: v3.0 https://github.com/mongodb/mongo/commit/604d172a093c041a53ceedbefb346f300b7b24c5

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            Dates

            • Created:
              Updated:
              Resolved:

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