Each messaging engine establishes an exclusive lock
on its data store. While the messaging engine is running, it maintains that
lock to ensure the integrity of the data within the data store.
Compare
your symptoms with those listed in the following table and examine the possible
solutions:
Symptom |
Cause |
Solution |
The messaging engine cannot
start nor failover to another server.
The messaging engine writes error
message CWSIS1519 |
The messaging engine cannot
connect to the database that you specified in the data source that you configured
to enable the messaging engine to
access its data store. |
|
After a delay of many minutes, the messaging engine cannot
failover to another server and writes error message CWSIS1519. |
Another instance of the same messaging engine is
holding the data store lock,
or the database has not released a data store lock
that was held by a failed instance of the same messaging engine. |
- If you can connect to the database, another instance of the messaging engine might
hold a lock on the data store.
Check for other running instances of the same messaging engine.
Only one instance of each messaging engine can
run in a cluster at a given time.
- After the failure of an instance of a messaging engine or
an application server that is running in a cluster, the database might not
have released the database locks that comprise the data store lock.
Use the administration tools for your relational database management system
to examine the locks on the SIBOWNER table.
If the database is still holding locks after the failure of a server, ensure
that you configure the liveness checking of the network connection between
the application server and the database server to enable prompt failover.
For example, examine the TCP keep alive parameter.
If you
are using DB2 for z/OS, you can examine the DB2 Idle Thread Timeout.
You
might need to use your database administration tools to force the release
of the lock on the data store.
|
The messaging engine fails
to start and writes error messages CWSIS1535 and CWSIS1519 |
The identifiers in the SIBOWNER table
do not match those of the messaging engine. |
- Check that the data source that you configured for the messaging engine refers
to the correct database.
- If the MEUUID identifiers do not match, check that
a previous messaging engine did not
use the same tables. If the tables already exist, DROP the
tables and CREATE them again for the new messaging engine.
- If the INCUUID identifiers do not match, another
instance of the same messaging engine is
running and has acquired the lock. Check for other running instances of the messaging engine.
|
The messaging engine starts
but then stops and writes error message CWSIS1519. |
The messaging engine has
lost its lock on the data store. |
- Check that you have connectivity to the database through the data source
that you specified. The messaging engine might
have lost network connectivity and be unable to maintain a connection with
the database.
- If you can connect to the database, another instance of the messaging engine might
have started and obtained a lock on the data store.
Check for other running instances of the messaging engine.
|