[SERVER-21693] Log a rollback summary Created: 30/Nov/15 Updated: 18/Feb/20 Resolved: 29/Mar/18 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Replication |
| Affects Version/s: | None |
| Fix Version/s: | 3.7.4 |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | James Wahlin | Assignee: | Kyle Suarez |
| Resolution: | Done | Votes: | 0 |
| Labels: | rollback-non-functional | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||||||||||||||||||||||||||||||
| Sprint: | Repl 2018-03-26, Repl 2018-04-09 | ||||||||||||||||||||||||||||||||
| Participants: | |||||||||||||||||||||||||||||||||
| Linked BF Score: | 60 | ||||||||||||||||||||||||||||||||
| Description |
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When a rollback is performed we should provide a summary statement in the mongoD log which provides:
The following is an example of what we print in 3.2.0-rc4. This example is rolling back 2 documents that this member contained and the primary did not. There is a summary of the actions taken ("rollback 5 d:2 u:0") but it is not in a form most users will understand.
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| Comments |
| Comment by Githook User [ 29/Mar/18 ] |
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Author: {'email': 'kyle.suarez@mongodb.com', 'name': 'Kyle Suarez', 'username': 'ksuarz'}Message: |
| Comment by Githook User [ 29/Mar/18 ] |
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Author: {'email': 'kyle.suarez@mongodb.com', 'name': 'Kyle Suarez', 'username': 'ksuarz'}Message: |
| Comment by Githook User [ 29/Mar/18 ] |
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Author: {'email': 'kyle.suarez@mongodb.com', 'name': 'Kyle Suarez', 'username': 'ksuarz'}Message: Revert " This reverts commit fee5ac1166c2b4a0a11e00e58f2d9c12d4567e25. Conflicts: |
| Comment by Kay Kim (Inactive) [ 28/Mar/18 ] |
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Thanks kyle.suarez – Probably will add a note to the rollback page to check the log message. We already have a generic https://docs.mongodb.com/manual/reference/log-messages/index.html#ROLLBACK section in the log message page, so it'll be a quick blurb that you can check the rollback status in the log messages or something. |
| Comment by Kyle Suarez [ 28/Mar/18 ] |
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kay.kim, I'm marking documentation changes as "Not Needed", as the new rollback algorithm doesn't change anything to make https://docs.mongodb.com/manual/core/replica-set-rollbacks/ outdated. However, we will now have a new rollback summary section that gets printed to the logs and looks something like this: https://gist.github.com/ksuarz/562faa6e84710331ff1be69df80475c1 Just giving the docs team a heads up in case this is something interesting to document. |
| Comment by Githook User [ 28/Mar/18 ] |
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Author: {'email': 'kyle.suarez@mongodb.com', 'name': 'Kyle Suarez', 'username': 'ksuarz'}Message: |
| Comment by Spencer Brody (Inactive) [ 16/Aug/17 ] |
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I agree that surfacing information about what happened during a rollback in a different way than we currently do could be valuable, but that is out of scope for this ticket. This ticket is simply about ensuring that the new rollback approach maintains parity with the old one. Can you file a separate feature request describing your proposal for what you'd like to see us do instead robert.guo? |
| Comment by Robert Guo (Inactive) [ 14/Aug/17 ] |
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It could be useful to also log the summary in a special collection (e.g. local.rollback_summary) so test suites that introduce random rollbacks can make more precise assertions on the correctness of the cluster during rollback by consulting the rollback summary collection |