Add a fault-tolerant commitlog replay mode for use in debugging#3887
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Add a fault-tolerant commitlog replay mode for use in debugging#3887
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When debugging broken commitlogs, we want to inspect the whole commitlog, including the part after the first error. This is in contrast with the way we want to replay in prod, where we'd rather get a hard error than an incorrect state. This commit adds a new flag to commitlog replay, `ErrorBehavior`. The `core` crate passes `ErrorBehavior::FailFast` when replaying commitlogs to reconstruct databases. Internal tooling (not in this repository) uses `ErrorBehavior::Warn` to print the entirety of a broken commitlog.
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kim
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Dec 16, 2025
Centril
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Dec 16, 2025
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# Description of Changes Based on #3887 . Review starting from commit 233b48c. We've encountered a commitlog which includes inserts into `st_table`, `st_column`, &c of the rows which describe `st_view`, `st_view_param`, &c. This caused replay to fail, as those rows were already inserted during bootstrapping, so we got set-semantic duplicate errors. With this commit, we ignore set-semantic duplicate errors when replaying a commitlog specifically for rows in system tables which describe system tables. We also have to do an additional fixup for sequences. This is described in-depth in comments added at the relevant locations. # API and ABI breaking changes N/a # Expected complexity level and risk 1 - I was careful not to swallow any errors which aren't obviously safe. # Testing - [x] Manually replayed commitlog which includes the above mentioned inserts, got error prior to this commit, no error with this commit.
aasoni
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Based on #3887 . Review starting from commit 233b48c. We've encountered a commitlog which includes inserts into `st_table`, `st_column`, &c of the rows which describe `st_view`, `st_view_param`, &c. This caused replay to fail, as those rows were already inserted during bootstrapping, so we got set-semantic duplicate errors. With this commit, we ignore set-semantic duplicate errors when replaying a commitlog specifically for rows in system tables which describe system tables. We also have to do an additional fixup for sequences. This is described in-depth in comments added at the relevant locations. N/a 1 - I was careful not to swallow any errors which aren't obviously safe. - [x] Manually replayed commitlog which includes the above mentioned inserts, got error prior to this commit, no error with this commit.
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Description of Changes
When debugging broken commitlogs, we want to inspect the whole commitlog, including the part after the first error.
This is in contrast with the way we want to replay in prod, where we'd rather get a hard error than an incorrect state.
This commit adds a new flag to commitlog replay,
ErrorBehavior. Thecorecrate passesErrorBehavior::FailFastwhen replaying commitlogs to reconstruct databases. Internal tooling (not in this repository) uses
ErrorBehavior::Warnto print the entirety of a broken commitlog.API and ABI breaking changes
Changes internal APIs only.
Expected complexity level and risk
1 - no change to behavior of SpacetimeDB.
Testing
None.