Advanced Queuing - Oracle

Messaging Gateway Questions
Why does the database not shut down when the Messaging Gateway
agent is running?
The MGW agent establishes connections with the database and those connections
prevent the database from shutting down for a SHUTDOWN NORMAL command. Call
dbms_mgwadm.shutdown to shut down the MGW agent before shutting down the
database.
Why does MGW_GATEWAY view always show an AGENT_STATUS of
START_SCHEDULED?
Messaging Gateway uses job queues in the Oracle database to start the MGW agent
process. At least one job queue process must be configured to execute queued jobs
in the background. The gateway job is scheduled to execute immediately, but will
not do so until a job queue process is available. If the gateway status remains
START_SCHEDULED for an extended period of time, it may indicate that the
database instance has been started with no or too few job queue processes. The
Messaging Gateway holds its job queue process for the lifetime of that MGW agent
session.
You should verify that the database instances have been started, with enough job
queue processes so one is available for use by Messaging Gateway. A minimum
value of 2 is recommended.
init.ora parameters:
JOB_QUEUE_PROCESSES specifies the number of job queue processes for each
instance.
Dynamic parameters:
ALTER SYSTEM SET JOB_QUEUE_PROCESSES = ;
After starting the Messaging Gateway agent, why does the MGW_
GATEWAY view show an AGENT_STATUS of NOT_STARTED?
The MGW_GATEWAY view provides status information about the gateway agent. A
NOT_STARTED status indicates that the agent is not running. If the MGW agent
encounters a fatal error while starting or running, the LAST_ERROR_MSG field is
nonnull.
Do the following:
1. Check if a MGW log file has been generated and whether it indicates any errors.
If a log file is not present, the gateway agent process was probably not started.
2. Verify that the listener has been started.
6-8 Oracle9i Application Developer’s Guide - Advanced Queuing