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  1. Core Server
  2. SERVER-21837

MongoD memory usage higher than wiredTigerCacheSizeGB for primary in replica set

    • Type: Icon: Bug Bug
    • Resolution: Duplicate
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: None
    • Component/s: Replication
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      3 node replica set on Windows (2 replicas and one arb).

      3 node replica set on Windows (2 replicas and one arb).

      I've been watching mongod memory fairly closely (SERVER-20991,
      SERVER-20104 etc). With 3.2, memory usage on my non-replica-set deployment is excellent and it is well within expectations for the given wiredTigerCacheSizeGB.

      Testing a replica-set with the same workload, the memory appears to push past this limit significantly: using a 4GB argument, actual memory usage is at 6.5 GB fairly quickly after kicking off the run.

      I haven't done a full run yet, but will attempt to do so to see if memory keeps climbing or if it levels off.

        1. memory.png
          174 kB
          Bruce Lucas
        2. memory-early.png
          167 kB
          Bruce Lucas
        3. metrics.2015-12-16T05-49-34Z-00000
          9.45 MB
          Nick Judson

            Unassigned Unassigned
            nick@innsenroute.com Nick Judson
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