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  1. Core Server
  2. SERVER-16952

Optimize oplog reader batching

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    • Icon: Improvement Improvement
    • Resolution: Done
    • Icon: Major - P3 Major - P3
    • None
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    • Replication
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    • Replication

    Description

      It is likely that batches are smaller since the primary can write with higher concurrency and lower latency causing replicating member to return smaller batches of documents during replication.

      If this is true this will lead to lower latency in replication "eventual consistency" but increased network traffic and larger load, both in cpu and contention, on both members.

      There are other reasons that the batches may be smaller including:

      • Change in lock acquisition (fairness)
      • Yielding and interleave behavior
      • Replication changes during re-write

      In order to better analyze this behavior we should be able to look at the replication network metrics (metrics.repl.network.getmores/ops) which record the reader side of replication.

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            backlog-server-repl Backlog - Replication Team
            scotthernandez Scott Hernandez (Inactive)
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              Created:
              Updated:
              Resolved: