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  1. Couchbase Server
  2. MB-28698

improve scan stat gathering

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    Description

      The stat gathering for scan uses atomics. But at very high concurrency, that doesn't seem to be scaling.

      After adding new stats for aggregates, the scan latency got worse in showfast:
      http://showfast.sc.couchbase.com/#/timeline/Linux/secondary/lat/MOI
      http://showfast.sc.couchbase.com/#/timeline/Linux/secondary/lat/Plasma

      The difference in results for build 5.5.0-2036 vs 5.5.0-2126.

      It would be better to split the stats into a pool of stats which the scans can update concurrently by taking out an object out of the pool and the final stats can be aggregated at collection time.

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          relates to

          Bug - A problem which impairs or prevents the functions of the product. MB-28017 Latency of aggregation queries is higher than expected

          • Major - Major loss of function.
          • Closed
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              deepkaran.salooja Deepkaran Salooja
              deepkaran.salooja Deepkaran Salooja
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