Notification Exception: (Env:Production) : : java.lang.String :
PreparedStatementCallback; SQL [ UPDATE txn_tracker set status=?,
schedule_dt=SYSDATE() where txn_id =? and status=? ];
Deadlock found when trying to get lock; try restart
How to cope with this Exception
Please suggest..
You have to catch it and retry the transaction. Some tips to reduce the chance of deadlocks in mysql:
http://dev.mysql.com/doc/refman/5.0/en/innodb-deadlocks.html
Related
In my project, a table has around 13 million rows and approximately 43 Gb of size. I tried to delete the first 1000 records using laravel delete method.But the execution takes more time and trow exception for me. The exception is
Illuminate\Database\QueryException : SQLSTATE[HY000]: General error: 1205 Lock wait timeout exceeded; try restarting transaction (SQL: delete from `demo_table` where `datetime` <= 2020-06-31 00:00:00 order by `id` asc limit 1000)
at r/laravel/framework/src/Illuminate/Database/Connection.php:664
660| // If an exception occurs when attempting to run a query, we'll format the error
661| // message to include the bindings with SQL, which will make this exception a
662| // lot more helpful to the developer instead of just the database's errors.
663| catch (Exception $e) {
> 664| throw new QueryException(
665| $query, $this->prepareBindings($bindings), $e
666| );
667| }
668|
you need to try add additional or change mysql configuration my.ini in Windows or my.cnf in Linux or Mac bellow [mysqld]
[mysqld]
wait_timeout=NumberValue
interactive_timeout = NumberValue
the value in seconds.
after you change it, you need to restart mysql services
You can handle it with nextToken or you can Use Queue for running thread in background
I have the following mysql pattern that I'm using:
try:
print ('111111')
self.cursor.execute(sql, values)
print ('222222') # print to see how long timeouts are taking...
except Exception as error:
# Most likely a deadlock, retry if NumAttemps <= MaxAttempts
logger.exception(error)
...
In another mysql client, to simulate a deadlock, I am doing something like this:
begin;
select * from records where id='10.5240-D5CF-3' for update;
This works, in that it will grab a deadlock and the mysql code will go into the except block, usually with the error:
pymysql.err.InternalError: (1205, 'Lock wait timeout exceeded; try restarting transaction')
Is there a way to specify how long the cursor will wait before it raises the timeout error / or before it 'gives up' if there is a lock? Are both handled by innodb_lock_wait_timeout, or are there multiple settings for this?
I'm using MySQL server (5.6) database extensively through its .NET connector (6.8.3). All tables are created with MyISAM engine for performance reasons. I have only one process with one thread accessing the DB sequentially, so there is no need for transactions and concurrency.
Please note: this is unlikely to be a timeout configuration issue, because my query is trivial. I did read all timeout related questions (links below). Of course, I may be wrong, but saying just "increase the net_write_timeout parameter" without explaining why exactly it can be relevant here is not an answer.
Some of my tables are created dynamically during program execution so I'm using create on first use idiom, with the following method to check whether the table exists:
private bool TableExists(Space baseSpace, Space extendedSpace)
{
var tableName = GenerateTableName(baseSpace, extendedSpace);
var sqlConnection = this.connectionPool.Take();
this.existsCommand.Connection = sqlConnection;
this.existsCommand.Parameters["#tableName"].Value = tableName.Trim('`');
var result = existsCommand.ExecuteScalar() as long?;
this.connectionPool.Putback(sqlConnection);
return result == 1;
}
The query inside the existsCommand is as follows (broken into two lines here for readability):
SELECT COUNT(*) FROM information_schema.tables
WHERE table_schema = 'my_schema' AND table_name = #tableName
The value of this.existsCommand.Parameters["#tableName"].Value variable contains the correct name of the table, that already exists in this case ("sample_matches_A_to_A_x").
The this.connectionPool.Take() method returns the first MySqlConnection object from my collection of available connections that meets the following predicate:
private bool IsAvailable(MySqlConnection connection)
{
return connection != null
&& connection.State == System.Data.ConnectionState.Open;
}
Usually this works correctly, for a number of hours and then suddenly an exception occurs on this line:
var result = existsCommand.ExecuteScalar() as long?;
With the following contents:
Fatal error encountered during command execution
Stack trace:
at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior)
at MySql.Data.MySqlClient.MySqlCommand.ExecuteScalar()
at implementation.SampleMatchesMySqlTable.TableExists(Space baseSpace, Space extendedSpace) in C:...\SampleMatchesMySqlTable.cs:line 168
Inner exception:
Unable to write data to the transport connection: Software caused connection abort.
Inner exception:
Software caused connection abort.
with ErrorCode equal to 10053 and SocketErrorCode being System.Net.Sockets.SocketError.ConnectionAborted
Stack trace of the innermost exception:
at System.Net.Sockets.Socket.Send(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
at System.Net.Sockets.NetworkStream.Write(Byte[] buffer, Int32 offset, Int32 size)
I've reviewed the following possible duplicates and unfortunately they don't seem relevant here, except one:
SHOW TABLES encountered Fatal error encountered during command execution
Unfortunately, it doesn't provide enough information to decide whether it is an exact duplicate nor it's answered.
There relate to timeout problems. My query is small, returns only one integer, and searches for a table in a meta-table containing something like 20 other tables.
Fatal error encountered during command execution. in C# when i use Insert Into
https://stackoverflow.com/questions/7895178/fatal-error-in-mysql
MySQL Exception - Fatal Error Encountered During Data Read
Fatal error encountered during data read
Fatal error causing timeout -mysql
ADO.Net Entity framework, Fatal error encountered during data read
Different error regarding reading the resultset:
Fatal error encountered during command execution
Syntax errors and connection string issues:
Mysql Fatal error encountered during command execution
fatal error encountered during execution... during update
Fatal error encountered during command execution
fatal error encountered during command execution during update
fatal error encountered during command execution c# mysql
Fatal error encountered during command execution with a mySQL INSERT
I have Fatal error encountered during command execution
MySql exception was unhandled - Fatal error encountered during command execution
https://stackoverflow.com/questions/24098561/mysql-fatal-error-encountered-during-command-execution-in-c-sharp
Fatal Error Encounter During Command Execution MySQL VB
"Fatal error encountered during command execution." mysql-connector .net
"Fatal error encountered during command execution."
C#, MySQL - fatal error encountered during command execution- Checked other solutions, something I am Missing
Creating a view:
"fatal error encountered during command execution" when trying to add a view from MySQL DB
Reading CSV files:
Fatal error encountered during command execution while importing from csv to mysql
MySQL fatal error encountered during command execution - looping through all csv files in folder for load data local infile
I ended up modifying the IsAvailable method as follows:
private bool IsAvailable(MySqlConnection connection)
{
var result = false;
try
{
if (connection != null)
{
result = connection.Ping();
}
}
catch (Exception e)
{
Console.WriteLine("Ping exception: " + e.Message);
}
return result && connection.State == System.Data.ConnectionState.Open;
}
The .Ping call seems to be better in verifying connection's state then its properties, although it's very poorly documented. From some other sources I've read in the meantime:
an alternative is to run a simple query like SELECT 1 FROM DUAL instead of calling Ping.
Also, there seems that sometimes a DataReader, even though it was disposed (everything is implemented with the using statement), is still attached to the connection for some brief period of time. Because of this I've modified the condition to this:
if (connection != null && connection.State == ConnectionState.Open)
The State property has the Executing value as long as a DataReader is attached to it, so additionally verifying if it's Open at the beginning works fine here.
We are using JBoss 5.1 w/ MDB backed by ActiveMQ RAR.
When a message on a queue is consumed and performs some database operations which then result in a deadlock, the deadlock is essentially hosing the entire instance of JBoss until it is restarted. By hosed, any subsequent messages consumed on that queue all fail with the follow exception:
Caused by: javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
The deadlock exception never references my code, which in turn make it very difficult for me to catch and handle.
For example, here is an exception of a deadlock exception:
2012-06-18 18:52:19,848 WARN [JDBCExceptionReporter] : SQL Error: 1213, SQLState: 40001
2012-06-18 18:52:19,848 ERROR [JDBCExceptionReporter] : Deadlock found when trying to get lock; try restarting transaction
2012-06-18 18:52:19,850 ERROR [AbstractFlushingEventListener] : Could not synchronize database state with session
org.hibernate.exception.LockAcquisitionException: Could not execute JDBC batch update
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:105)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
at org.hibernate.ejb.AbstractEntityManagerImpl$1.beforeCompletion(AbstractEntityManagerImpl.java:504)
at com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple.beforeCompletion(SynchronizationImple.java:101)
at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.beforeCompletion(TwoPhaseCoordinator.java:269)
at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.end(TwoPhaseCoordinator.java:89)
at com.arjuna.ats.arjuna.AtomicAction.commit(AtomicAction.java:177)
at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1423)
at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:137)
at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:75)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.endTransaction(MessageInflowLocalProxy.java:435)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.finish(MessageInflowLocalProxy.java:314)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.after(MessageInflowLocalProxy.java:230)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.invoke(MessageInflowLocalProxy.java:136)
at $Proxy677.afterDelivery(Unknown Source)
at org.apache.activemq.ra.MessageEndpointProxy$MessageEndpointAlive.afterDelivery(MessageEndpointProxy.java:128)
at org.apache.activemq.ra.MessageEndpointProxy.afterDelivery(MessageEndpointProxy.java:69)
at org.apache.activemq.ra.ServerSessionImpl.afterDelivery(ServerSessionImpl.java:224)
at org.apache.activemq.ActiveMQSession.run(ActiveMQSession.java:897)
at org.apache.activemq.ra.ServerSessionImpl.run(ServerSessionImpl.java:169)
at org.jboss.resource.work.WorkWrapper.execute(WorkWrapper.java:205)
at org.jboss.util.threadpool.BasicTaskWrapper.run(BasicTaskWrapper.java:260)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.sql.BatchUpdateException: Deadlock found when trying to get lock; try restarting transaction
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:2013)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1449)
at com.mysql.jdbc.jdbc2.optional.StatementWrapper.executeBatch(StatementWrapper.java:721)
at org.jboss.resource.adapter.jdbc.WrappedStatement.executeBatch(WrappedStatement.java:774)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
... 29 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)
at com.mysql.jdbc.Util.getInstance(Util.java:382)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1064)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3603)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3535)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1989)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2150)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2626)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2119)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2415)
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1976)
... 34 more
2012-06-18 18:52:19,851 WARN [arjLoggerI18N] : [com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator_2] TwoPhaseCoordinator.beforeCompletion - failed for com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple#480671ab
javax.persistence.PersistenceException: org.hibernate.exception.LockAcquisitionException: Could not execute JDBC batch update
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:614)
at org.hibernate.ejb.AbstractEntityManagerImpl$1.beforeCompletion(AbstractEntityManagerImpl.java:513)
at com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple.beforeCompletion(SynchronizationImple.java:101)
at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.beforeCompletion(TwoPhaseCoordinator.java:269)
at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.end(TwoPhaseCoordinator.java:89)
at com.arjuna.ats.arjuna.AtomicAction.commit(AtomicAction.java:177)
at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1423)
at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:137)
at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:75)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.endTransaction(MessageInflowLocalProxy.java:435)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.finish(MessageInflowLocalProxy.java:314)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.after(MessageInflowLocalProxy.java:230)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.invoke(MessageInflowLocalProxy.java:136)
at $Proxy677.afterDelivery(Unknown Source)
at org.apache.activemq.ra.MessageEndpointProxy$MessageEndpointAlive.afterDelivery(MessageEndpointProxy.java:128)
at org.apache.activemq.ra.MessageEndpointProxy.afterDelivery(MessageEndpointProxy.java:69)
at org.apache.activemq.ra.ServerSessionImpl.afterDelivery(ServerSessionImpl.java:224)
at org.apache.activemq.ActiveMQSession.run(ActiveMQSession.java:897)
at org.apache.activemq.ra.ServerSessionImpl.run(ServerSessionImpl.java:169)
at org.jboss.resource.work.WorkWrapper.execute(WorkWrapper.java:205)
at org.jboss.util.threadpool.BasicTaskWrapper.run(BasicTaskWrapper.java:260)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: org.hibernate.exception.LockAcquisitionException: Could not execute JDBC batch update
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:105)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:365)
at org.hibernate.ejb.AbstractEntityManagerImpl$1.beforeCompletion(AbstractEntityManagerImpl.java:504)
... 22 more
Caused by: java.sql.BatchUpdateException: Deadlock found when trying to get lock; try restarting transaction
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:2013)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:1449)
at com.mysql.jdbc.jdbc2.optional.StatementWrapper.executeBatch(StatementWrapper.java:721)
at org.jboss.resource.adapter.jdbc.WrappedStatement.executeBatch(WrappedStatement.java:774)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:70)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:268)
... 29 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLTransactionRollbackException: Deadlock found when trying to get lock; try restarting transaction
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:407)
at com.mysql.jdbc.Util.getInstance(Util.java:382)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1064)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3603)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3535)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1989)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2150)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2626)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2119)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2415)
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1976)
... 34 more
2012-06-18 18:52:19,912 WARN [TxConnectionManager] : Connection error occured: org.jboss.resource.connectionmanager.TxConnectionManager$TxConnectionEventListener#6acc2da9[state=NORMAL mc=org.jboss.resource.adapter.jdbc.xa.XAManagedConnection#2c9e906 handles=0 lastUse=1340059939649 permit=true trackByTx=true mcp=org.jboss.resource.connectionmanager.JBossManagedConnectionPool$OnePool#10015060 context=org.jboss.resource.connectionmanager.InternalManagedConnectionPool#4643d6d5 xaResource=org.jboss.resource.adapter.jdbc.xa.XAManagedConnection#2c9e906 txSync=null]
com.mysql.jdbc.jdbc2.optional.MysqlXAException: XA_RBDEADLOCK: Transaction branch was rolled back: deadlock was detected
at com.mysql.jdbc.jdbc2.optional.MysqlXAConnection.mapXAExceptionFromSQLException(MysqlXAConnection.java:605)
at com.mysql.jdbc.jdbc2.optional.MysqlXAConnection.dispatchCommand(MysqlXAConnection.java:584)
at com.mysql.jdbc.jdbc2.optional.MysqlXAConnection.end(MysqlXAConnection.java:479)
at org.jboss.resource.adapter.jdbc.xa.XAManagedConnection.end(XAManagedConnection.java:246)
at com.arjuna.ats.internal.jta.resources.arjunacore.XAResourceRecord.topLevelAbort(XAResourceRecord.java:396)
at com.arjuna.ats.arjuna.coordinator.BasicAction.doAbort(BasicAction.java:3270)
at com.arjuna.ats.arjuna.coordinator.BasicAction.doAbort(BasicAction.java:3248)
at com.arjuna.ats.arjuna.coordinator.BasicAction.Abort(BasicAction.java:1933)
at com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator.end(TwoPhaseCoordinator.java:97)
at com.arjuna.ats.arjuna.AtomicAction.commit(AtomicAction.java:177)
at com.arjuna.ats.internal.jta.transaction.arjunacore.TransactionImple.commitAndDisassociate(TransactionImple.java:1423)
at com.arjuna.ats.internal.jta.transaction.arjunacore.BaseTransaction.commit(BaseTransaction.java:137)
at com.arjuna.ats.jbossatx.BaseTransactionManagerDelegate.commit(BaseTransactionManagerDelegate.java:75)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.endTransaction(MessageInflowLocalProxy.java:435)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.finish(MessageInflowLocalProxy.java:314)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.after(MessageInflowLocalProxy.java:230)
at org.jboss.ejb3.mdb.inflow.MessageInflowLocalProxy.invoke(MessageInflowLocalProxy.java:136)
at $Proxy677.afterDelivery(Unknown Source)
at org.apache.activemq.ra.MessageEndpointProxy$MessageEndpointAlive.afterDelivery(MessageEndpointProxy.java:128)
at org.apache.activemq.ra.MessageEndpointProxy.afterDelivery(MessageEndpointProxy.java:69)
at org.apache.activemq.ra.ServerSessionImpl.afterDelivery(ServerSessionImpl.java:224)
at org.apache.activemq.ActiveMQSession.run(ActiveMQSession.java:897)
at org.apache.activemq.ra.ServerSessionImpl.run(ServerSessionImpl.java:169)
at org.jboss.resource.work.WorkWrapper.execute(WorkWrapper.java:205)
at org.jboss.util.threadpool.BasicTaskWrapper.run(BasicTaskWrapper.java:260)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
2012-06-18 18:52:19,914 INFO [ServerSessionImpl:153] : Endpoint failed to process message. Reason: Endpoint after delivery notification failure
I can catch the subsequent errors (the errors on subsequent messages to the queue):
Caused by: javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: Cannot open connection
But I'm not even sure what to do with it, maybe I can get a new EntityManager that isn't hosed, but I'm getting via Injection to begin with... The only way I know to fix this error is to restart.
I assume that the initial Deadlock is happening as part of ending the transaction in the Queue which is why it's not happening in my code, but does any idea of a way I can handle this gracefully?
Update:
All DataSources are MySQL XA
In transaction-jboss-beans.xml we have transactionTimeout set to 300
There is no way to handle container transaction exception gracefully.
It decides to rollback whatever the reason is and you have no control against it. A complex option to get notified about such exceptions and rollback events may be to write a JCA connector which enrolls fake resources into the distributed transaction manager for each MDB transaction.
I would recommend you to investigate what happens and fix the trouble from its source.
Here is a dead-lock scenario, it always involve multiple threads: if two pieces of code use the same entities but in different order, a first thread will lock resource A (a row, a table or a Java monitor) and wait for B when a second thread have already locked resource B and now waits for A.
So a distributed dead-lock is possible between Java monitors and Database resources and that case is complex to diagnose. The full system is stuck until the transaction timeouts at both ends, Java thread dumps and database sessions and locks must be scanned.
In your case, as MySQL detects the dead-lock itself, it means only database resources are involved.
To help, I guess you should reduce the number of SQL queries run in your batch update for one JMS message, one transaction. With concurrent messages consumed at the same time, working on transaction applying large number of rows, a deadlock situation is more likely to occur.
But it is strange that your JBoss server is stuck after rollback because of a DB-only dead-lock:
either you have exhausted the number of JDBC connections from the DataSource pool
or there is no more MySQL server-side connection available
or all message beans are in dead-lock situation too
the transaction timeout may be too high to get rollbacks in a reasonable time frame
So either you reduce MDB concurrency by down sizing the corresponding pool, either you reduce the number of updates per transaction - maybe even as small as one update per JMS message...
I was able to resolve this by isolating each transaction using the following method:
Annotate the MDB with:
#TransactionManagement(value = TransactionManagementType.BEAN)
Thus telling the MDB that the Bean itself will manage the transaction and not the container (outside of my code), next, inject the necessary resources:
#Resource
MessageDrivenContext mc;
UserTransaction tx;
To create and manage my own transactions
tx = mc.getUserTransaction();
tx.begin();
//Do work
tx.commit();
The above step can be repeated for each block of code.
Using very granular transactions I was able to trace where in my code the lock / race condition was happening. Once I solved that I was able to back out some of the more granular transaction management.
I have a block like so:
begin
# some SQL request
rescue Mysql::Error => e
logputs "Mysql::Error occurred, retrying in 10s: #{e.message}"
sleep 10
retry
end
But when a "Lost connection to MySQL server" error occurred, this block was not able to catch it and retry (the MySQL server was restarted). Any idea how I can properly catch this exception?
Thanks!
From your comment it looks like what's happening is that a Mysql::Error exception is being thrown, but then caught by ActiveRecord which then throws an ActiveRecord::StatementInvalid exception (which isn't very helpful behaviour in this case!).
I'd say change your rescue to catch the AR::StatementInvalid exception and see what that does for you.
Are you sure you are rescuing the correct type of exception?
Try using the following code:
rescue StandardError => e
puts e
That should output any exception that is raised and more importantly you will be able to see the specific type. Then you can adjust your rescue statement to be more specific.