[SERVER-43615] syncSource diagnostics are incorrect Created: 24/Sep/19 Updated: 06/Dec/22 Resolved: 30/Sep/19 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | 4.0.2 |
| Fix Version/s: | None |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Danny Hatcher (Inactive) | Assignee: | Backlog - Replication Team |
| Resolution: | Duplicate | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
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| Issue Links: |
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| Assigned Teams: |
Replication
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| Operating System: | ALL | ||||||||
| Steps To Reproduce: | 1. Start a 3 member replica set on 4.0.2 or later. |
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| Participants: | |||||||||
| Description |
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In 4.0.1, the syncSourceId for a node identifies the member of the replica set the node is syncing from. Starting in 4.0.2, the syncSourceId for a node doesn't change unless the node is either stepping down or stepping up itself. Additionally, if chaining is disabled there is no logging explicitly stating the new sync source when there was in 4.0.1. 4.0.1:
4.0.2:
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| Comments |
| Comment by Siyuan Zhou [ 30/Sep/19 ] |
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Thanks for the explanation! Closing this as a dup. |
| Comment by Danny Hatcher (Inactive) [ 30/Sep/19 ] |
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My statement was for a situation in which I would have expected a Secondary node to change its sync source, a change in Primaries with chaining disabled, but didn't. However, as you linked, this does appear to be a duplicate of |
| Comment by Siyuan Zhou [ 30/Sep/19 ] |
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daniel.hatcher, I'd like to clarify your observation a little before the investigation.
In 4.0.2, we always return the sync source id if the node has a sync source or -1. It sounds reasonable to start choosing a new sync source on stepdown and reset the sync source ID to -1 on stepup, so the statement doesn't sound a bug to me if the node doesn't need to change sync source on steady state replication. The symptoms about chaining you described sounds similar to |