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Type: Bug
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Resolution: Fixed
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Priority: Major - P3
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Affects Version/s: None
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Component/s: Replication
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None
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Minor Change
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Repl 2020-06-15, Repl 2020-07-27
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0
Capped 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.
- is related to
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SERVER-42372 Reads against capped collections aren't banned within transactions
- Closed
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SERVER-47574 Ban non-transaction snapshot reads on capped collections
- Closed
- related to
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SERVER-63813 Allow transactions and snapshot reads on capped collections
- Backlog
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SERVER-40684 Ban transactions against capped collections on non-shard-servers
- Closed