I have the main thread that spawns thread #2 which uses the same hibernate Session in the main thread. Thread #2 just does a "select 1" every few min to keep the db connection alive because of a long running process from the main thread. Once the main thread is done w/ the processing, it calls a commit but i get the error:
Caused by: org.hibernate.TransactionException: JDBC commit failed
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:161)
at org.springframework.orm.hibernate3.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:655)
... 5 more
Caused by: java.sql.SQLException: Can't call commit when autocommit=true
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:930)
at com.mysql.jdbc.ConnectionImpl.commit(ConnectionImpl.java:1602)
at org.hibernate.transaction.JDBCTransaction.commitAndResetAutoCommit(JDBCTransaction.java:170)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:146)
... 6 more
Within the main thread, it creates inner transactions which are committed successfully, it's just the outer transaction when it commits that throws this error. I don't see what could be changing the autocommit boolean. Before I introduced the 2nd thread to keep the connection alive, this error had never occurred.
Even though I think you should seriously reconsider the way you are using Hibernate, you can bypass this issue by adding a relaxAutoCommit parameter to the JDBC driver in its URL.
Details from MySQL documentation:
relaxAutoCommit
If the version of MySQL the driver connects to does not support transactions, still allow calls to commit(), rollback() and setAutoCommit() (true/false, defaults to 'false')?
Default: false
Since version: 2.0.13
Source: https://dev.mysql.com/doc/connector-j/5.1/en/connector-j-reference-configuration-properties.html