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  1. Couchbase Server
  2. MB-26494

Cursor Dropping - Improve Trigger Policy

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Details

    • Improvement
    • Resolution: Duplicate
    • Major
    • 6.5.0
    • 4.6.2, 5.0.0
    • couchbase-bucket
    • None

    Description

      Currently cursor dropping is triggered when mem_used for a bucket meets a specific threshold (default 95%).

      Policy is here
      Default is here
      Using % of memory used as a trigger is insufficient. For example with the current threshold, a single checkpoint could occupy all memory up to the HWM, cause a resident ratio of zero and yet still not invoke cursor dropping. Similarly a lower threshold below the HWM would invoke cursor dropping as part of normal behaviour.

      This MB is to implement a more sophisticated scheme whereby the size of the checkpoints themselves are taken into account in order to invoke cursor dropping.

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          duplicates

          Bug - A problem which impairs or prevents the functions of the product. MB-29227 Couchbase Server can get into a livelock state due to high checkpoint memory usage

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MB-29227 Couchbase Server can get into a livelock state due to high checkpoint memory usage

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

          Bug - A problem which impairs or prevents the functions of the product. MB-27663 Improve backpressure/tmpOOM threshold when DWQ is large

          • Major - Major loss of function.
          • Closed
          For Gerrit Dashboard: MB-26494
          # Subject Branch Project Status CR V
          100026,3 MB-26494: Add stat for items in all checkpoints master kv_engine Status: NEW 0 -1

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              owend Daniel Owen
              dhaikney David Haikney (Inactive)
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              Dates

                Created:
                Updated:
                Resolved:

                Gerrit Reviews

                  There is 1 open Gerrit change

                  PagerDuty