Technical Advisory 104309 #18309
Technical Advisory 104309 #18309
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Nick approved offline. |
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src/current/advisories/a104309.md
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| ## Description | ||
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| A [rangefeed](https://www.cockroachlabs.com/docs/stable/create-and-configure-changefeeds#enable-rangefeeds) bug may cause a [checkpoint](https://www.cockroachlabs.com/docs/stable/how-does-an-enterprise-changefeed-work) to be emitted prematurely in rare cases, before all writes below the checkpoint timestamp have been emitted. This could occur if nodes are overloaded or if long-running transactions (several seconds) are involved, such that intent resolution only replicates to a follower running a rangefeed more than 10 seconds after the transaction began. If a cluster using changefeeds experiences this bug, changefeeds will omit these write events, and the following error will be logged: |
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We should link the expression, "write intent" to some reference reading. I think this is probably the best spot. https://www.cockroachlabs.com/docs/v23.2/architecture/transaction-layer#write-intents
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| The specific conditions to trigger the bug are: | ||
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| 1. An explicit or cross-range transaction commits, then asynchronously resolves all of its intents and removes its transaction record on all relevant leaseholders. |
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Explicit OR cross-range transactions is a strange subset of all transactions. Is it explicit AND cross-range?
Also, aren't all write intents removed async after the transaction commits during the cleanup stage? The language here just doesn't make sense to me.
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The way this is written reads (to me) as if this behavior is unusual.
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This might be worth clarifying. The intention here is "All explicit transactions and cross-range implicit transactions are affected."
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The reason is that single-range implicit transactions don't write intents.
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@shralex Is the suggested edit accurate? https://github.com/cockroachdb/docs/pull/18309/files#r1496690828 (sorry about the HTML, it's a tooling edge case)
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| The specific conditions to trigger the bug are: | ||
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| 1. An explicit or cross-range transaction commits, then asynchronously resolves all of its intents and removes its transaction record on all relevant leaseholders. |
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| 1. An explicit or cross-range transaction commits, then asynchronously resolves all of its intents and removes its transaction record on all relevant leaseholders. | |
| 1. A transaction commits, then asynchronously resolves all of its intents and removes its transaction record on all relevant leaseholders. To be affected by the bug, the transaction must be either an <a href="https://www.cockroachlabs.com/docs/stable/transactions#sql-statements">explicit transaction</a> with `BEGIN` and a `COMMIT` clauses, or an implicit transaction (single-statement write) that involves multiple ranges. |
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@shannonbradshaw Is this more clear?
Technical Advisory 104309
Preview: src/current/advisories/a104309.md