What are the meanings of various Transaction failure messages while using EJB3

Issue

• While running our EJB 3.0 Based method invocation we are seeing the following kind of Exceptions what are the meaning of these transaction related errors ?

21:45:10,876 ERROR [stderr] (EJB default - 1) java.sql.SQLException: You cannot commit during a managed transaction!
21:45:10,876 ERROR [stderr] (EJB default - 1)   at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnection.jdbcCommit(BaseWrapperManagedConnection.java:1036)
21:45:10,876 ERROR [stderr] (EJB default - 1)   at org.jboss.jca.adapters.jdbc.WrappedConnection.commit(WrappedConnection.java:757)
21:45:10,876 ERROR [stderr] (EJB default - 1)   at dao.TestDAO.executeMultiple(Unknown Source)
21:45:10,876 ERROR [stderr] (EJB default - 1)   at ejb3.IntCalculatorBean.hello(Unknown Source)

OR

21:51:58,727 ERROR [stderr] (EJB default - 2) java.sql.SQLException: You cannot rollback during a managed transaction!
21:51:58,727 ERROR [stderr] (EJB default - 2)   at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnection.jdbcRollback(BaseWrapperManagedConnection.java:1081)
21:51:58,728 ERROR [stderr] (EJB default - 2)   at org.jboss.jca.adapters.jdbc.WrappedConnection.rollback(WrappedConnection.java:778)
21:51:58,728 ERROR [stderr] (EJB default - 2)   at dao.TestDAO.executeMultiple(Unknown Source)

OR

21:52:48,401 ERROR [stderr] (EJB default - 3) java.sql.SQLException: You cannot set autocommit during a managed transaction!
21:52:48,402 ERROR [stderr] (EJB default - 3)   at org.jboss.jca.adapters.jdbc.BaseWrapperManagedConnection.setJdbcAutoCommit(BaseWrapperManagedConnection.java:939)
21:52:48,402 ERROR [stderr] (EJB default - 3)   at org.jboss.jca.adapters.jdbc.WrappedConnection.setAutoCommit(WrappedConnection.java:715)
21:52:48,402 ERROR [stderr] (EJB default - 3)   at dao.TestDAO.setAutoCommitFalse(Unknown Source)