[DOCS-13775] Investigate changes in SERVER-47824: Ban transaction snapshot reads on capped collections Created: 20/Jul/20 Updated: 13/Nov/23 Resolved: 11/Feb/21 |
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| Status: | Closed |
| Project: | Documentation |
| Component/s: | manual, Server |
| Affects Version/s: | None |
| Fix Version/s: | 4.7.0, Server_Docs_20231030, Server_Docs_20231106, Server_Docs_20231105, Server_Docs_20231113 |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Backlog - Core Eng Program Management Team | Assignee: | Naomi Pentrel (Inactive) |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Participants: | |||||||||
| Days since reply: | 2 years, 51 weeks, 6 days ago | ||||||||
| Epic Link: | DOCSP-9747 | ||||||||
| Story Points: | 2 | ||||||||
| Description |
DescriptionDownstream Change Summary Transaction snapshot reads are now banned on capped collections. Description of Linked TicketCapped collections typically (always?) delete records with an unreplicated/untimestamped write. Those deletions will always become visible in a newer transaction. So if a transaction uses snapshot with an atClusterTime (e.g. coming from mongos), it may not see some deleted documents even if they existed at the point in time requested. Snapshot transactions without atClusterTime might still work if the snapshot is open before the deletions happen probably because they hold onto the WT txn and the snapshot. But I am not 100% sure. Either way, it seems that we will still have to ban transaction snapshot reads on capped collections unless we choose to timestamp the capped collection deletions. Scope of changesPages to review and update:
Impact to Other DocsMVP (Work and Date)Resources (Scope or Design Docs, Invision, etc.) |
| Comments |
| Comment by Githook User [ 11/Feb/21 ] |
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Author: {'name': 'Naomi Pentrel', 'email': '5212232+npentrel@users.noreply.github.com', 'username': 'npentrel'}Message: |