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  1. Core Server
  2. SERVER-78509

Add storage stats to replicated slow op log entries

    • Replication
    • Fully Compatible
    • v7.0, v6.0, v5.0, v4.4
    • Repl 2023-07-24, Repl 2023-11-27, Repl 2023-12-11

      The current implementation of replicated slow operation logging, found in oplog_applier_impl.cpp finishAndLogApply() only logs very basic information about the slow operation: the BSON of the oplog entry itself, its wall clock duration, and its size.

      For normal (client-generated) slow query operation logging, we also include a number of fields that are relevant only to client-initiated queries, like the read preference and the number of bytes returned. Finally, we include a storage section that includes information on how many bytes were read and written.
      It is this last section that can be very valuable. I undertook a recent slowness investigation that turned out to be insert operations to a collection with very large multi-key index entries, and this could have been diagnosed a lot faster if we had the storage information in the replication slow logs like we do for regular slow log entries.

            Assignee:
            pavithra.vetriselvan@mongodb.com Pavithra Vetriselvan
            Reporter:
            milkie@mongodb.com Eric Milkie
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              Updated:
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