9.7 Problem determination
The following information is presented to help you become familiar with successful messaging engine startup, and some common problems.
No problems
This shows what you can expect to see in systemOut.log on server start up for a messaging engine that starts successfully.
SID0016I: Messaging engine Node1.server1-amsterdamBus is in state Joined. . SID0016I: Messaging engine Node1.server1-amsterdamBus is in state Starting. . SID0016I: Messaging engine Node1.server1-amsterdamBus is in state Started. .
When you start a server that is part of a cluster bus member, then the messaging engine will not always be started. Only one server in the cluster will have a specific messaging engine activated on it and this messaging engine might already be started.
If this is the case, then you will see the messaging engine in the state Joined, but not Start or Started. This is perfectly normal and means that the messaging engine is in a stand-by state, waiting to be activated should the currently active instance of the messaging engine become unavailable.
When you have more than one messaging engine in a bus, you will also see the messaging engines communicate with each other. Every messaging engine in the bus connects to every other messaging engine in the bus...
SIT0028I: The connection for messaging engine Node1.server1-amsterdamBus in bus amsterdamBus to messaging engine Node2.server2-amsterdamBus started. . SIP0382I: messaging engine B68588EF698F4527 responded to subscription request, Publish Subscribe topology now consistent. .
If you see the error shown below, the database that the messaging engine points to contains the unique ID of a different messaging engine. The most likely cause of this is when you create a bus, add a server to that bus using the default Cloudscape database and start the server. Later, you delete and recreate a bus of the same name. The newly created messaging engine will use a default data source that points to the same database used by the old messaging engine, and this database will contain the ID of the old messaging engine.
This error can also be caused by configuring any messaging engine with the same message store as another messaging engine.
CWSIS9999E: Attempting to obtain an exclusive lock on the data store. SIS1535E: The messaging engine's unique id does not match that found in the data store. ME_UUID=1C80283E64EAB2CA, ME_UUID(DB)=B1C40F1182B0A045 IS1519E: Messaging engine Node1.server1-amsterdamBus cannot obtain the lock on its data store, which ensures it has exclusive access to the data. SID0027I: Messaging engine Node1.server1-amsterdamBus cannot be restarted because a serious error has been reported. SID0016I: Messaging engine Node1.server1-amsterdamBus is in state Stopped.
For a data store, the simplest solution is to drop the tables in the database, or delete and recreate the database and then restart the server. Another solution is to change the messaging engine's data store by changing the schema, user, and database configured for the messaging engine. For a file store, delete the files, or the directory paths. See Adding the bus member for more details
This exception shows what can be thrown to a JMS client on a createConnection call.
javax.jms.JMSException: CWSIA0241E: An exception was received during the call to the method JmsManagedConnectionFactoryImpl.createConnection: com.ibm.websphere.sib.exception.SIResourceException: CWSIT0019E: No suitable messaging engine is available in bus amsterdamBus.
Causes of this exception include: