Do not reuse logs that end with an incomplete record#1336
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Add Reader::HasIncompleteTrailingRecord to report when EOF discards a partial tail record. Skip WAL and MANIFEST reuse when this flag is set, preventing append from turning a safely discarded fragment into corruption. Related: google#1287
uadhran
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June 11, 2026 10:10
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Summary
Fixes a corruption risk when
reuse_logsis enabled and a WAL or MANIFEST ends with an incomplete record (writer crashed mid-record). Previouslylog::Readersilently discarded the partial tail, then reuse appended new data — turning a safe discard into likely corruption.Changes
db/log_reader.h/db/log_reader.cc: AddHasIncompleteTrailingRecord(); set when EOF discards truncated header, partial payload, or incomplete fragmented record.db/db_impl.cc: Skip WAL reuse inRecoverLogFilewhen the flag is set.db/version_set.cc: Skip MANIFEST reuse inRecoverwhen the flag is set.db/log_test.cc: Unit tests for complete vs incomplete EOF.db/recovery_test.cc: Integration test that truncated WAL is not reused (reuse_logs).Testing
Linux (CMake Release):
Did not run Windows/macOS builds locally; relies on CI.
Related: #1287