[SERVER-66835] [test-only bug] Compare number of chunks in balancing_based_on_size.js Created: 27/May/22 Updated: 29/Oct/23 Resolved: 01/Jun/22 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | 6.0.3, 6.1.0-rc0 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Pierlauro Sciarelli | Assignee: | Pierlauro Sciarelli |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||||||
| Operating System: | ALL | ||||||||
| Backport Requested: |
v6.0
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| Sprint: | Sharding EMEA 2022-06-13 | ||||||||
| Participants: | |||||||||
| Linked BF Score: | 21 | ||||||||
| Description |
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Change this data size comparison with a comparison on number of chunks: this is equivalent because that part of the test simply needs to verify that no move has happened due to expected no-op balancing rounds. Long explanation (from a build failure)When a range deletion happens: Note that points 1-2 are not happening in the same storage transaction, and - even if they would - the update of the in-memory stats registry would still not happen atomically. The test uses the get stats for balancing command that - when invoked for a namespace: The test is doing the following:
According to the failure, the actual data size on the donor was 6 before the no-op rounds and became 7 after the no-op rounds. However, no move has happened and the rounds really resulted in no-ops. The only viable explanation is that the following flow interleaving happened: 1 - A - 2 - B. Basically the balancer stats registry retrieved the data size after an orphaned document was deleted but before the number of orphans was updated. This resulted in an off-by-one. |
| Comments |
| Comment by Githook User [ 14/Oct/22 ] |
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Author: {'name': 'Pierlauro Sciarelli', 'email': 'pierlauro.sciarelli@mongodb.com', 'username': 'pierlauro'}Message: |
| Comment by Githook User [ 01/Jun/22 ] |
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Author: {'name': 'Pierlauro Sciarelli', 'email': 'pierlauro.sciarelli@mongodb.com', 'username': 'pierlauro'}Message: |