Background Error Handling

Currently in RocksDB, any error during a write operation (write to WAL, Memtable Flush, background compaction etc) causes the database instance to go into read-only mode by default and further user writes are not accepted. The variable ErrorHandler::bg_error_ is set to the failure Status. The DBOptions::paranoid_checks option controls how aggressively RocksDB will check and flag errors. The default value of this option is true. The table below shows the various scenarios where errors are considered and potentially affect database operations.

Error Reason	When bg_error_ is set
Sync WAL	Always
Memtable flush	DBOptions::paranoid_checks is true
Max allowed space reached during memtable flush (SstFileManager::IsMaxAllowedSpaceReached())	Always
Max allowed space reached during compaction (SstFileManager::IsMaxAllowedSpaceReached())	Always
DB::CompactFiles	DBOptions::paranoid_checks is true
Background compaction	DBOptions::paranoid_checks is true
Write	DBOptions::paranoid_checks is true