[SERVER-39234] Sharding an empty collection in mixed-shard version configurations may leave all chunks on the primary shard Created: 28/Jan/19 Updated: 29/Oct/23 Resolved: 30/Jan/19 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Sharding |
| Affects Version/s: | 4.0.5 |
| Fix Version/s: | 4.0.6, 4.1.8 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Kaloian Manassiev | Assignee: | Kaloian Manassiev |
| 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: |
v4.0
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| Sprint: | Sharding 2019-02-11 | ||||||||
| Participants: | |||||||||
| Linked BF Score: | 50 | ||||||||
| Description |
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In partially upgraded clusters, whose config server is at version 4.0.5 and shards are at pre-4.0.3 (includes 3.6), sharding an empty collection with hashed sharding or performing map/reduce with outputting to an empty collection (with any kind of sharding) will end up placing all chunks on the primary shard of the collection. This is not a correctness issue, but it means that the balancer will have to move non-empty chunks later on and thus defeats the purpose of pre-sharding the collection. |
| Comments |
| Comment by Githook User [ 30/Jan/19 ] |
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Author: {'email': 'kaloian.manassiev@mongodb.com', 'name': 'Kaloian Manassiev'}Message: |
| Comment by Githook User [ 30/Jan/19 ] |
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Author: {'email': 'kaloian.manassiev@mongodb.com', 'name': 'Kaloian Manassiev'}Message: (cherry picked from commit 1c61dfa3307c2009dd29c893b8d2b08af6bcf7d6) |
| Comment by Githook User [ 30/Jan/19 ] |
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Author: {'email': 'kaloian.manassiev@mongodb.com', 'name': 'Kaloian Manassiev'}Message: |