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  1. Couchbase Server
  2. MB-7293

Incorrect active resident ratio calculation

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Incomplete
    • Affects Version/s: 2.0
    • Fix Version/s: 2.0.1
    • Component/s: ns_server
    • Security Level: Public
    • Labels:
      None
    • Environment:
      2.0-1967-rel

      Description

      Seeing incorrect active_resident ratio on some nodes in a cluster.

      The web UI shows 0 percent active resident ratio, while ep-engine shows 83 %, which is the correct value.

      • added screenshot from UI.

      Stats from node -
      [root@grape-004 ~]# /opt/couchbase/bin/cbstats localhost:11210 -b default all | grep resident
      ep_num_non_resident: 850006
      ep_tap_backfill_resident: 0.9
      vb_active_num_non_resident: 122506
      vb_active_perc_mem_resident: 83
      vb_pending_num_non_resident: 0
      vb_pending_perc_mem_resident: 0
      vb_replica_num_non_resident: 727500
      vb_replica_perc_mem_resident: 0

      The current ns_server code shows the following calculation for the "active resident ratio" and it seems to be hitting the exception

      In menalus_stats.erl:

      ResidenceCalculator = fun (NonResident, Total) ->
      try (Total - NonResident) * 100 / Total
      catch error:badarith -> 0
      end

      It looks like there is an exception being thrown in Alk's calculation which causes the result to be 0.

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            • Assignee:
              ketaki Ketaki Gangal
              Reporter:
              ketaki Ketaki Gangal
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              Dates

              • Created:
                Updated:
                Resolved:

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