[SERVER-16952] Optimize oplog reader batching Created: 20/Jan/15 Updated: 06/Dec/22 Resolved: 09/Mar/17 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Replication |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | Scott Hernandez (Inactive) | Assignee: | Backlog - Replication Team |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Assigned Teams: |
Replication
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| Participants: |
| Description |
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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:
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. |