[DOCS-12230] Manual oplog resize in 4.0 after unclean shutdown can lose committed writes Created: 03/Dec/18 Updated: 30/Oct/23 |
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| Status: | Closed |
| Project: | Documentation |
| Component/s: | manual, Rel Notes, Server |
| Affects Version/s: | None |
| Fix Version/s: | Server_Docs_20231030 |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | Kevin Pulo | Assignee: | Ravind Kumar (Inactive) |
| Resolution: | Won't Do | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
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| Days since reply: | 1 year, 14 weeks, 2 days ago | ||||||||||||
| Epic Link: | DOCSP-1769 | ||||||||||||
| Story Points: | 0.2 | ||||||||||||
| Description |
DescriptionThis is a specific manifestation of Until (and including) 3.4, the supported and documented procedure to resize the oplog involved:
In 3.6 this was changed to a "live resize" using the replSetResizeOplog command. However, if the old manual resize procedure is performed on an uncleanly shutdown 4.0 mongod, it can result in unapplied oplog entries being lost. This will cause the data on that node to no longer be consistent with the rest of the replica set (which can in turn lead to unspecified problems later on). Reproducer:
Remediation: Given that the old procedure has been around forever, it's reasonable to believe that experienced MongoDB admins:
It's also not hard to imagine scenarios where this might be done after an unclean shutdown, for example, an admin wanting to reduce the size of the oplog after an out-of-disk-space crash. This ticket is to request:
Scope of changesImpact to Other DocsMVP (Work and Date)Resources (Scope or Design Docs, Invision, etc.) |
| Comments |
| Comment by Education Bot [ 31/Oct/22 ] |
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Hello! This ticket has been closed due to inactivity. If you believe this ticket is still important, please reopen it and leave a comment to explain why. Thank you! |
| Comment by Asya Kamsky [ 21/Dec/18 ] |
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I'd like to second that adding a "WARNING" block to the 3.4 and earlier version of the oplog resize page about this is super-important.
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