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  1. Couchbase Server
  2. MB-56547

Selectively enable out-of-seqno backfill only when expected to be faster than seqno

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    • 0
    • KV 2023-2, KV 2023-4

    Description

      As per analysis in MB-56346, out-of-seqno (OSO) backfill is not always beneficial compared to seqno backfill - for larger collections and/or small value sizes it can be significantly slower than "classic" seqno backfill.

      We need to modify the logic of when OSO backfill is performed to not only consider when it is possible (i.e. client supports OSO, single collection from zero), but also when it is expected to be faster than seqno.

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          causes

          Bug - A problem which impairs or prevents the functions of the product. MB-57608 OSO backfill: memcached log formatting error

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Closed

          Task - A task that needs to be done. MB-58741 XDCR - dev test for OSO broken due to KV changes

          • Major - Major loss of function.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MB-57882 Re-enable OSO (Revert MB-56428)

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved

          Bug - A problem which impairs or prevents the functions of the product. MB-59304 [BP to 7.2.x] Re-enable OSO (Revert MB-56428)

          • Critical - Crashes, loss of data, severe memory leak.
          • Resolved
          For Gerrit Dashboard: MB-56547
          # Subject Branch Project Status CR V
          189920,10 MB-56547 [1/3]: Add option to disable DCP OSO backfill at runtime neo kv_engine Status: MERGED +2 +1
          190097,7 MB-56547 Move CollectionsFlushTest::storeItems() to KVBucketTest neo kv_engine Status: MERGED +2 +1
          190098,7 MB-56547 [2/3]: Add DCP OSO backfill 'auto' mode neo kv_engine Status: MERGED +2 +1
          190185,4 MB-56547 [3/3]: Change default DCP OSO backfill mode to 'auto' neo kv_engine Status: MERGED +2 +1
          192614,2 MB-56547 [4/3]: Fix OSOBackfillResumesFromNextItemAfterPause test under OSO backfill mode auto neo kv_engine Status: MERGED +2 +1
          193043,6 MB-56547: Fix log message formatting in tryAndScheduleOSOBackfill neo kv_engine Status: MERGED +2 +1
          196287,2 Merge commit '5a72c5497' into 'couchbase/master' master kv_engine Status: MERGED +2 +1
          196381,3 Merge commit 'cd05c2a33' into 'couchbase/master' master kv_engine Status: MERGED +2 +1
          196458,1 Merge commit '6133110e2' into 'couchbase/master' master kv_engine Status: MERGED +2 +1

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              ashwin.govindarajulu Ashwin Govindarajulu
              drigby Dave Rigby (Inactive)
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              Dates

                Created:
                Updated:
                Resolved:

                PagerDuty