Heuristic Recovery with the Transaction Coordinator Log
Modes of Heuristic Recovery
There are three modes are heuristic recovery:
- Automatic heuristic recovery after a crash.
- Manual heuristic recovery when
- No heuristic recovery.
Manual Heuristic Recovery
Manual heuristic recovery occurs when
--tc-heuristic-recover is set. This might be needed if the server finds prepared transactions during crash recovery that are not in the transaction coordinator log. For example, you might see an error like this:
[ERROR] Found 1 prepared transactions! It means that mysqld was not shut down properly last time and critical recovery information (last binlog or tc.log file) was manually deleted after a crash. You have to start mysqld with --tc-heuristic-recover switch to commit or rollback pending transactions.