[SERVER-78915] [only affect testing] A shard may be involved in more than one migration per balancer round when using the "Random migrations" feature Created: 13/Jul/23 Updated: 14/Jul/23 Resolved: 13/Jul/23 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | 5.0.19, 4.4.23, 6.0.8, 7.0.0-rc7 |
| Fix Version/s: | None |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Silvia Surroca | Assignee: | [DO NOT USE] Backlog - Sharding EMEA |
| Resolution: | Duplicate | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Assigned Teams: |
Sharding EMEA
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| Operating System: | ALL | ||||||||
| Participants: | |||||||||
| Description |
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When the balancerShouldReturnRandomMigrations fail point is enabled, the balancer may schedule multiple migrations involving the same shards. That is happening because the shards involved in a chosen migration are not removed from the availableShards list.
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| Comments |
| Comment by Silvia Surroca [ 13/Jul/23 ] |
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cris.insignarescuello@mongodb.com tommaso.tocci@mongodb.com sergi.mateo-bellido@mongodb.com I considered this a bug because this is not an expected behavior of the balancer. I also wanted to give this ticket some visibility since it could be the root cause for still non-solved bugs, like for those BFs with migration failures that were closed as trivial because of the lack of coredumps and data files (BF-29107, BF-29140). |