[SERVER-49929] Policy for placing system collections in admin or config DB Created: 27/Jul/20 Updated: 08/Jan/24 Resolved: 05/Oct/20 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Replication |
| Affects Version/s: | None |
| Fix Version/s: | 4.9.0 |
| Type: | New Feature | Priority: | Major - P3 |
| Reporter: | A. Jesse Jiryu Davis | Assignee: | A. Jesse Jiryu Davis |
| 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: | Repl 2020-09-21, Repl 2020-10-05, Repl 2020-10-19 | ||||||||
| Participants: | |||||||||
| Description |
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The "admin" and "config" databases each contain a handful of system collections, holding replica set or sharding state. I think the admin and config DBs were historically distinguished by different locking rules, but these days there is no rationale for keeping them separate. Let's consider merging them. However, it seems likely that merging them is more difficult than it's worth. In that case, let's add to the Replication Architecture Guide some information about these two databases, and a policy for where new system collections are placed as we develop new features in the future. |
| Comments |
| Comment by Githook User [ 05/Oct/20 ] |
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Author: {'name': 'A. Jesse Jiryu Davis', 'email': 'jesse@mongodb.com', 'username': 'ajdavis'}Message: |
| Comment by Kaloian Manassiev [ 29/Jul/20 ] |
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I don't think it is true that we don't allow transactions on the config database. We certainly use transactions for refining the document shard key (blake.oler to confirm). Perhaps it's only certain config collections that disallow it? |