Network Deployment (Distributed operating systems), v8.0 > Reference > Troubleshoot tips


Messaging engine troubleshooting tips

Use this set of specific tips to help you troubleshoot problems with service integration messaging engines.



Messaging engine start fails because runtime is not yet initialized

A messaging engine fails to start and the following error is displayed in the WAS administrative console: 

The messaging engine
<name> cannot be started as there is no runtime
initialized for it yet, retry the operation once it has been initialized.
If dynamic configuration reload is enabled for this bus, then the servers
must be restarted.

Before trying to start the messaging engine again, make sure that we have restarted the server. For the runtime to initialize successfully, the application server must be started.

To find out whether a start up problem is preventing the messaging engine runtime from initializing, check for error messages in the SystemOut.log of the hosting server.

New feature: Beginning in WAS v8.0 you can configure the server to use the HPEL log and trace infrastructure instead of using SystemOut.log , SystemErr.log, trace.log, and activity.log files or native z/OS logging facilities. If you are using HPEL, you can access all of your log and trace information using the LogViewer command-line tool from your server profile bin directory. See the information about using HPEL to troubleshoot applications for more information on using HPEL.New feature:


Messaging engine cannot start up because of a known error in the Informix JDBC Driver 3.00JC1

When attempting to use the Informix JDBC driver 3.00JC1 to store data, the messaging engine cannot start up and the following error message might appear in the WAS SystemOut.log file: 

00000022 SibMessage E [RetireBus:retire_web.000- RetireBus] CWSIS0002E:
The messaging engine encountered an exception while starting.
Exception: com.ibm.ws.sib.msgstore.PersistenceException: CWSIS1501E:
The data source has produced an unexpected exception: java.sql.BatchUpdateException:
Unique constraint (informix.u114_62) violated.
00000022 SibMessage E [RetireBus:retire_web.000- RetireBus] CWSID0035E:
Messaging engine retire_web.000-RetireBus cannot be started;
detected error reported during com.ibm.ws.sib.msgstore.impl.MessageStoreImpl start()
00000022 SibMessage E [RetireBus:retire_web.000- RetireBus] CWSID0027I:
Messaging engine retire_web.000-RetireBus cannot be restarted because a
serious error has been reported.T]
00000022 SibMessage I [RetireBus:retire_web.000- RetireBus] CWSID0016I:
Messaging engine retire_web.000-RetireBus is in state Stopped.

There is a known defect (PTS 172471) in the Informix JDBC Driver 3.00JC1.

To avoid this error, upgrade the Informix JDBC Driver to 3.00JC2.


Problem determination for a data store

You can create a dump, in reduced form, of the data in the data store for a messaging engine. The output is intended for use by IBM Service personnel. Contact your support organization for information about how to run the command.

If there is a problem with the data in the data store, it can be hard to diagnose from the trace output. However, you can create a dump, in XML format, of the data in the data store. This makes diagnosis easier because it is a human readable representation that can be transformed to other formats as required. We can create a data store dump by typing the following command in wsadmin.sh:

The dump is created as an XML file in the WAS_HOME/logs/server1 directory. The file is named according to the format: messaging_engine_name UUID timestamp.xml

The format of the file is illustrated in the following example: 

<MessageStore>
<itemStreams>  
<ItemStreamLink id="0" state="Available">      
<class>com.ibm.ws.sib.msgstore.ItemStream
</class>      
<priority>5
</priority>      
<canExpireSilently>
</canExpireSilently>      
<storageStrategy>STORE_NEVER
</storageStrategy>      
<expiryTime>0
</expiryTime>      
<sequence>0
</sequence>      
<tranID>null
</tranID>      
<tickValue>0
</tickValue>      
<items>          
<ItemLink id="2" state="Available" refCount="3" refCountDecreasing="false">              
<class>com.ibm.ws.sib.msgstore.Item
</class>              
<priority>5
</priority>              
<canExpireSilently>
</canExpireSilently>              
<storageStrategy>STORE_NEVER
</storageStrategy>              
<expiryTime>0
</expiryTime>              
<sequence>1
</sequence>              
<tranID>null
</tranID>              
<tickValue>0
</tickValue>          
</ItemLink>
</items>
</ItemStreamLink>
</itemStreams>
</MessageStore>


Messaging engines cause database contention messages

When a messaging engine uses a data store for the message store, if the same messaging engine is accidentally started twice, a database contention message is displayed: 

CWSIS1546I: The messaging engine, ME_UUID={0}, INC_UUID={1}, has lost
an existing lock or failed to gain an initial lock on the data store.

To resolve the problem:



User ID not supported exception when connecting to a Network Attached Apache Derby v10.3 database

When you test the connection to your Network Attached Apache Derby v10.3 database, you get the following exception: 

java.lang.Exception: java.sql.SQLException: null userid not supported
DSRA0010E: SQL State = null, Error
When you create a new Network Attached Apache Derby data store, by default you get a blank authentication alias. If you use Apache Derby in Network Attached mode with the DB2 Universal JDBC Driver (that is, you use the "JDBC provider for Derby Network Server using the (DB2) Universal JDBC Driver"), specify an authentication alias. This requirement is documented in Data source minimum required settings for Apache Derby.

The need for an authentication alias only applies to the "JDBC provider for Derby Network Server using the (DB2) Universal JDBC Driver". This driver is deprecated and is replaced by the "JDBC provider for Derby Network Server using Derby Client", which does not need an authentication alias. See also Configure a JDBC data source for a messaging engine.


Possible causes of the XAResourceNotAvailableException exception and how to take appropriate action

When the deleteNode command is used for a node that hosts messaging engines, those messaging engines are deleted. When new messaging engines are re-created following the addNode command, they have different identifiers and so during transaction recovery it is not possible to connect to the old messaging engines. A message identifying the XAResourceNotAvailableException exception is generated in the SystemOut.log file for each server that hosts a messaging engine.

To solve this problem, follow the procedure described in Resolve indoubt transactions.

The XAResourceNotAvailableException exception can also be thrown when a server in a cluster bus member fails over. In this case, no operator intervention is required to recover and resolve transactions.


Problems when you re-create a service integration bus

If you delete a service integration bus, and later create a new bus with the same name, the messaging engine fails to start and messages such as the following are generated in SystemOut.log: 
[8/11/04 21:55:01:439 CDT] 0000000f SibMessage    I
[LateBus:xyzsun15.server1-LateBus] isAlive: MessagingEngine suffered common mode error.
Correct error (see logs) and restart server.
[8/11/04 21:55:01:468 CDT] 0000000f SibMessage    I
[LateBus:xyzsun15.server1-LateBus] isAlive: MessagingEngine will be stopped
because of common mode error.
No failover will occur.
[8/11/04 21:55:01:493 CDT] 0000000f SibMessage    I
[LateBus:xyzsun15.server1-LateBus] Messaging Engine
xyzsun15.server1-LateBus not in state from which stop is valid: Starting
[8/11/04 21:55:01:513 CDT] 0000000f SibMessage    I
[LateBus:xyzsun15.server1-LateBus] isAlive: MessagingEngine stopped because
of common mode error. Correct error (see logs) and restart server.
[8/11/04 21:57:01:431 CDT] 0000000e SibMessage    I
[LateBus:xyzsun15.server1-LateBus] isAlive: MessagingEngine suffered
common mode error.
Correct error (see logs) and restart server.

The messaging engine failed to start because the database directory for the messaging engine still exists after deletion of the bus and manually remove it.

To delete the Apache Derby database for a non-existent messaging engine, delete the database directory that is located in PROFILE_ROOT/databases/com.ibm.ws.sib, where PROFILE_ROOT is the directory in which profile-specific information is stored.

We must stop WAS before you can delete the database files.

For other databases, you can either delete all of the rows from the data store tables or you can drop all of the data store tables. These tables are in the schema that you configured for the data store. For a list of the tables, see Data store tables.

See Data store life cycle.


Problems communicating with foreign buses

To enable communication between buses, a foreign bus and a service bus integration link must be created. On the first bus, the name of the foreign bus must match the name of the second bus that becomes a foreign bus, and the name of the foreign bus for this second bus must match the name of the first bus. The service integration bus link must be have the same name on both buses.

You may see the following type of error if the configuration is not correct, for example because the service integration bus links do not match: 

SibMessage    E   [TechBus:TechCluster.000-TechBus]
CWSIT0057E: The inter-bus connection BookstoreBus failed in the remote
messaging engine on host aixp401.rchland.ibm.com with reason:
CWSIT0067E: Inter-bus connection BookstoreBus in bus BookstoreBus
is not available.


Problems when attempting to communicate with a renamed foreign bus

The administrative console panel used for configuring the properties of a service integration bus link can also be used to change the foreign bus name that the link is pointing to. However, not alter the name of the foreign bus after it has been configured. If you do, any messaging engines that already hold state information about the link will not be able to use the link until the foreign bus name is reset to its previous value.


Possible causes of a JMSException with a wrapped SILimitExceeded exception

When the number of messages held by a destination reaches its limiting threshold, any attempt to send a message to that destination fails with a JMSException with a wrapped SILimitExceeded exception. The destination continues to fail with this exception until the number of messages held by the destination reduces below the limiting threshold.

To obtain an accurate count of the number of available messages, you can monitor the Available Message Count PMI statistic for queue and topicspace destinations. If the number of available messages increases, take action to balance the system. Consider stopping producers from sending new messages until the destination consumes the available messages.

Examine the following list for possible causes and solutions for this problem:



Corruption problems on system restarts

It is possible, although rare, for a messaging engine, destination or link to be corrupted after a restart of the system. If this corruption occurs you will see a message indicating the problem. If the problem lies with the messaging engine, the messaging engine will not start. If a destination or link is corrupted, the relevant messaging engine will start, but the destination or link will not be usable on that messaging engine.

If you do not know the cause of the problem, contact your IBM service representative to establish the cause before attempting to resolve the situation.

If you know the cause of the problem, for example, you are aware of an issue with your database, resolve it...

  1. Use the administrative console to ensure that the configuration files are synchronized across the system, by navigating to System administration -> Nodes then clicking Full Resynchronize. This operation can take several minutes to run.

  2. If the problem still exists, complete one of the following tasks:

    • Delete the corrupted object and recreate it. Messages produced or received before the corruption occurred will be lost.

    • Restore the system from a backup, see Restore a data store and recovering its messaging engine. Messages produced or received since the backup was taken will be lost.



Retrive the status of messaging engines in the administrative console

To be able to retrieve the status of messaging engines, be logged into the administrative console with at least monitor authority. If you do not have this authority, the messaging engine status is displayed as "Unavailable", even if the messaging engine has started.

If you are not logged in with the authority needed to retrieve the status of messaging engines, an error message such as the following is logged in the server systemOut log file: 

[4/20/05 10:49:57:083 CDT] 0000004b RoleBasedAuth A
SECJ0305I: The role-based authorization check failed for admin-authz
operation SIBMessagingEngine:stateExtended.
The user UNAUTHENTICATED (unique ID: unauthenticated) was not granted any of  the following required roles: administrator, operator, configurator, monitor.
Where the user ID shown in the message is the user ID that you used to log in to the administrative console.


Enable an application to be started before a required messaging engine has started

If an application depends on a messaging engine being available, then the messaging engine must be started before the application can be run. If you want application server to start an application automatically, you should develop the applications to test that any required messaging engine has been started and, if needed, wait for the messaging engine. If this technique is used in a startup bean, then the startup bean method should perform the test and wait work in a separate thread (using the standard WorkManager methods), so that the application server startup is not delayed.

For an example of code to test and wait for a messaging engine, see Applications with a dependency on messaging engine availability.


Messaging engine failover is not supported for mixed version clusters containing v6 servers

A messaging engine that is hosted on a WAS v7.0 or later server cannot fail over to a messaging engine that is hosted on a WAS v6 server. If we have a cluster bus member that consists of a mixture of v6 and later servers, you must make sure the high availability policy is configured to prevent this type of failover.

To prevent failover of a v7.0 or later messaging engine to a v6 server, configure the high availability policy for the messaging engine so that the cluster is effectively divided into one set of servers for v6 and another set of servers for v7.0 or later, and the v7.0 or later messaging engine is restricted to the servers at v7.0 or later. See Configure messaging engine failover for mixed version clusters.
Service integration high availability and workload sharing configurations
Messaging engines
Troubleshoot help from IBM
Configure high availability and workload sharing of service integration
Configure messaging engine failover for mixed version clusters
Configure messaging engines
Configure messaging engine properties
List the messaging engines defined for a server bus member
List the messaging engines for a cluster bus member
Add a messaging engine to a cluster
Remove a messaging engine from a cluster
List the messaging engines in a bus
Add additional messaging engines to a cluster bus member
Remove a messaging engine from a bus
Create the database, schema and user ID for a messaging engine
Start a messaging engine
Stop a messaging engine
Display the runtime properties of a messaging engine
Manage messaging engines with administrative commands
Use HPEL to troubleshoot applications

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