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  1. Core Server
  2. SERVER-49919

sizes of indexes on replSet members are very different

    • Type: Icon: Bug Bug
    • Resolution: Cannot Reproduce
    • Priority: Icon: Major - P3 Major - P3
    • None
    • Affects Version/s: 4.0.12
    • Component/s: Replication
    • None
    • ALL

      We are running a mongodb v4.0 replSet on bare metal servers. Recently one replSet member crashed and all data was lost. To bring it back into the replSet, all databases had to be cloned. A few days later, the replSet member was up & runing & in sync.
      However, we observed that the size of the _id index of a (capped) collection was more than twice as large (423 vs 180 GB). The index sizes of the other secondary are quite similar to the primary though.
      That's a problem because such huge _id index does not fit in RAM anymore since the server has "only" 376 GB of RAM.

      Please see attached the collection stats of the primary and both secondaries.

            Assignee:
            dmitry.agranat@mongodb.com Dmitry Agranat
            Reporter:
            kay.agahd@idealo.de Kay Agahd
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              Created:
              Updated:
              Resolved: