[SERVER-62563] Support sharding for collectionUUID parameter of aggregate command Created: 12/Jan/22 Updated: 29/Oct/23 Resolved: 14/Feb/22 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | 5.3.0 |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Gregory Noma | Assignee: | Moustafa Maher |
| 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 | ||||||||||||||||||||
| Sprint: | Replication 2022-02-07, Repl 2022-02-21 | ||||||||||||||||||||
| Participants: | |||||||||||||||||||||
| Description |
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Currently the collectionUUID option for the aggregate command is disallowed on mongos.
Context change: In the case of sharded collection, documents can be spanned to multiple shards, so the aggregation request can be directed to any subset of the shards, and if the targeted subset doesn't include the primaryShard of the database that may result in not finding the collection corresponding to the given collectionUUID. To solve this problem we came up with two solutions: 2- Only allow collectionUUID parameter for commands that it must hit the primaryShard.
We have decided to go with the second solution for sharded aggregation command, so we are going to allow the collectionUUID parameter for only $indexStats and $collStats aggregation pipelines as replicator only needs these two pipelines. |
| Comments |
| Comment by Githook User [ 07/Feb/22 ] |
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Author: {'name': 'Moustafa Maher Khalil', 'email': 'm.maher@mongodb.com', 'username': 'moustafamaher'}Message: |