INSERT INTO DistributedLock (Resource, CreatedAt) SELECT ‘expirationmanager’, ‘ 05:04:35.387605’ FROM dual WHERE NOT EXISTS ( SELECT * FROM DistributedLock WHERE Resource = ‘expirationmanager’ AND CreatedAt > ‘ 05:04:05. AWS Events RDS Deadlocks AWS RDS Deadlocks A deadlock is caused when two or more transactions hold locks that the other transactions require. INSERT INTO DistributedLock (Resource, CreatedAt) SELECT ‘locks:schedulepoller’, ‘ 05:04:35.387605’ FROM dual WHERE NOT EXISTS ( SELECT * FROM DistributedLock WHERE Resource = ‘locks:schedulepoller’ AND CreatedAt > ‘ 05:03:35.387605’) (0x80004005): Deadlock found when trying to get lock try restarting transactionĪt .ReadPacket()Īt .GetResult(Int32& affectedRow, Int64& insertedId)Īt .GetResult(Int32 statementId, Int32& affectedRows, Int64& insertedId)Īt .NextResult(Int32 statementId, Boolean force)Īt .NextResult()Īt .ExecuteReader(CommandBehavior behavior)Īt .ExecuteNonQuery()Īt (IDbConnection cnn, CommandDefinition& command, Action`2 paramReader)Īt (IDbConnection cnn, CommandDefinition& command)Īt (String resource, TimeSpan timeout)Īt ()Īt _Displa圜lass6.b_0(MySqlConnection connection) I am working currently on liferay version 5.1.1 and with mysql 5.0.67 database. Is this an implementation problem og the MySql adaptor or something deeper ? It happens a few time every day but not related to specific events. Once concurrency is added, the problem will remain.I get this error in the application lock on my server: LATEST DETECTED DEADLOCK - 03:23:08 0x20ec (1) TRANSACTION: TRANSACTION 82199210, ACTIVE 59 sec fetching rows mysql tables in use 2, locked 2 LOCK WAIT 16 lock struct (s), heap size 1136, 618 row lock (s) MySQL thread id 94048, OS thread handle 13292, query id 1096831619 localhost 12. However, I think your solution with re-using the connection from the pool will only solve the problem inside that particular thread. It sounds like this is the issue you addressed for the test bot. The above scenario is a standard cache/lock pattern, and using async queries for the cache could potentially introduce a thundering herd problem, which the lock is supposed to eliminate. This is my assumption of how async queries work, since I've never used the mysql async feature before, please correct me if I'm wrong. #5 Write to cache (cache write is actually delayed.
With MySQL table-level locks, the timeout method must be used to resolve deadlocks. Note that the InnoDB instant deadlock detection algorithm also works in this case, because the serializing lock is a row-level lock.
Mysql deadlock timeout serial#
I can think of at least one scenario where this could become a problem: In that way, all transactions happen in a serial fashion.
Mysql deadlock timeout how to#
How to Avoid Lock Issues The creation of locks can be avoided by using an isolation level mechanism available in all transactional databases. 1.) Does this belong in core? The way the Drupal is designed, this would easily fit into a custom cache backend.Ģ.) Ins't this approach inherently "dangerous"? Using async queries for writing cache may improve speed, but the application is now under the wrong assumption that the operation has been performed. Deadlocks are situations in which multiple processes accessing the same database each hold locks needed by the other processes in such a way that none of the processes can proceed.
0 kommentar(er)
