Disable recycle_log_file_num with kTolerateCorruptedTailRecords (#7271)

Summary:
The two features are naturally incompatible. WAL recycling expects the recovery to succeed upon encountering a corrupt record at the point where new data ends and recycled data remains at the tail. However, `WALRecoveryMode::kTolerateCorruptedTailRecords` must fail upon encountering any such corrupt record, as it cannot differentiate between this and a real corruption, which would cause committed updates to be truncated.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7271

Reviewed By: riversand963

Differential Revision: D23169923

Pulled By: ajkr

fbshipit-source-id: 2cf8a3bcd2c9a0ecb0055a84725047a10fd4db50
This commit is contained in:
Andrew Kryczka 2020-08-17 18:19:45 -07:00 committed by Facebook GitHub Bot
parent 92593d511a
commit 5d5ff82408
3 changed files with 24 additions and 7 deletions

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@ -3,6 +3,7 @@
### Bug fixes ### Bug fixes
* Fix a performance regression introduced in 6.4 that makes a upper bound check for every Next() even if keys are within a data block that is within the upper bound. * Fix a performance regression introduced in 6.4 that makes a upper bound check for every Next() even if keys are within a data block that is within the upper bound.
* Fix a possible corruption to the LSM state (overlapping files within a level) when a `CompactRange()` for refitting levels (`CompactRangeOptions::change_level == true`) and another manual compaction are executed in parallel. * Fix a possible corruption to the LSM state (overlapping files within a level) when a `CompactRange()` for refitting levels (`CompactRangeOptions::change_level == true`) and another manual compaction are executed in parallel.
* Sanitize `recycle_log_file_num` to zero when the user attempts to enable it in combination with `WALRecoveryMode::kTolerateCorruptedTailRecords`. Previously the two features were allowed together, which compromised the user's configured crash-recovery guarantees.
* Fix a bug where a level refitting in CompactRange() might race with an automatic compaction that puts the data to the target level of the refitting. The bug has been there for years. * Fix a bug where a level refitting in CompactRange() might race with an automatic compaction that puts the data to the target level of the refitting. The bug has been there for years.
### New Features ### New Features

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@ -90,12 +90,22 @@ DBOptions SanitizeOptions(const std::string& dbname, const DBOptions& src) {
} }
if (result.recycle_log_file_num && if (result.recycle_log_file_num &&
(result.wal_recovery_mode == WALRecoveryMode::kPointInTimeRecovery || (result.wal_recovery_mode ==
WALRecoveryMode::kTolerateCorruptedTailRecords ||
result.wal_recovery_mode == WALRecoveryMode::kPointInTimeRecovery ||
result.wal_recovery_mode == WALRecoveryMode::kAbsoluteConsistency)) { result.wal_recovery_mode == WALRecoveryMode::kAbsoluteConsistency)) {
// kPointInTimeRecovery is inconsistent with recycle log file feature since // - kTolerateCorruptedTailRecords is inconsistent with recycle log file
// we define the "end" of the log as the first corrupt record we encounter. // feature. WAL recycling expects recovery success upon encountering a
// kAbsoluteConsistency doesn't make sense because even a clean // corrupt record at the point where new data ends and recycled data
// shutdown leaves old junk at the end of the log file. // remains at the tail. However, `kTolerateCorruptedTailRecords` must fail
// upon encountering any such corrupt record, as it cannot differentiate
// between this and a real corruption, which would cause committed updates
// to be truncated -- a violation of the recovery guarantee.
// - kPointInTimeRecovery and kAbsoluteConsistency are incompatible with
// recycle log file feature temporarily due to a bug found introducing a
// hole in the recovered data
// (https://github.com/facebook/rocksdb/pull/7252#issuecomment-673766236).
// Besides this bug, we believe the features are fundamentally compatible.
result.recycle_log_file_num = 0; result.recycle_log_file_num = 0;
} }

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@ -528,7 +528,10 @@ TEST_F(DBWALTest, PreallocateBlock) {
#endif // !(defined NDEBUG) || !defined(OS_WIN) #endif // !(defined NDEBUG) || !defined(OS_WIN)
#ifndef ROCKSDB_LITE #ifndef ROCKSDB_LITE
TEST_F(DBWALTest, FullPurgePreservesRecycledLog) { TEST_F(DBWALTest, DISABLED_FullPurgePreservesRecycledLog) {
// TODO(ajkr): Disabled until WAL recycling is fixed for
// `kPointInTimeRecovery`.
// For github issue #1303 // For github issue #1303
for (int i = 0; i < 2; ++i) { for (int i = 0; i < 2; ++i) {
Options options = CurrentOptions(); Options options = CurrentOptions();
@ -564,7 +567,10 @@ TEST_F(DBWALTest, FullPurgePreservesRecycledLog) {
} }
} }
TEST_F(DBWALTest, FullPurgePreservesLogPendingReuse) { TEST_F(DBWALTest, DISABLED_FullPurgePreservesLogPendingReuse) {
// TODO(ajkr): Disabled until WAL recycling is fixed for
// `kPointInTimeRecovery`.
// Ensures full purge cannot delete a WAL while it's in the process of being // Ensures full purge cannot delete a WAL while it's in the process of being
// recycled. In particular, we force the full purge after a file has been // recycled. In particular, we force the full purge after a file has been
// chosen for reuse, but before it has been renamed. // chosen for reuse, but before it has been renamed.