[AMQ-3654] JDBC Master/Slave : Slave cannot acquire lock when the master loose database connection.

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 5.5.0
• Fix Version/s: 5.7.0

Environment

Unix/Redhat 5.6
ActiveMQ 5.5.0
Oracle 10G

• Assignee: Gary Tully
• Reporter: Richard Martin
• Created: 06/Jan/12 15:11
• Updated: 20/Aug/12 11:31
• Resolved: 13/Jun/12 21:55

Description

Our configuration is JDBC Master/Slave with one master and one slave. When the master is started, he acquire the database lock.
Then when the slave is started, he wait to acquire the database lock. When the master loose the network connection to the database, the lock in the database is not removed and the slave connot acquire the database lock. In this situation, the master is unable to respond to client (due to network failure)
and the slave is not started because he can't acquire the database lock.

When the master is killed, the slave can't acquire the database lock too. After the network connection is restored, when the master starts, it cannot
acquire lock to the database (because the lod lock is always present) so now, we have two slaves and no master.

Please, refer to this issue which is the same problem : AMQ-1958

Issue Links

• is related to: AMQ-3681 DatabaseLocker should first cancel locking SQL statement before closing the SQL connection
• is related to: AMQ-1958 JDBC master/slave deadlock when connection is lost