This topic describes how to investigate why a topic space on a
service integration bus is full.
Why and when to perform this task
When a topic space becomes full, exceptions will be returned when
you attempt to publish a message to that topic space. The most probable reason
for a topic space filling up is that the publishing application is producing
messages faster than they can be consumed by the subscribing application or
applications. However there could be other causes, such as dormant subscribers
or broken communications links.
Another possible cause is a regular increase
in message traffic, for example at certain times of day. Consider increasing
the high message threshold to overcome this problem.
Steps for this task
- Click Service integration -> Buses -> bus_name -> Destinations to
display a list which includes all the topic spaces on that bus. Click the
name of the topic space that is full.
- Click Publication points -> publication_point_name,
then on the Runtime tab review the value of the Current
message depth. If this value increases steadily, the publishing
application is outpacing the subscribers. Click Subscriptions to
display the subscriptions for the topic space. For each subscription, click
on the subscription name and examine the Current message depth.
If all the subscriptions are filling up, reduce the rate at which the publishing
application is publishing messages.
Note: If the topic space is
mediated, perform the following checks for each mediation point the message
could have been sent to or consumed from.
- If only one subscription is filling up, the problem lies with the
related subscribing application. If the subscription is nondurable, modify
the subscribing application to increase the speed of consumption.
- If the subscription is a durable subscription, click Messages and
ensure that the message at the top of the list changes with time; this indicates
that the subscribing application is actually consuming messages. If the message
does not change but the application is running, either delete the subscription
or increase the high message threshold of the publication point.
- Determine which messaging engines the publishing and subscribing
applications are connected to, see Determining which messaging engine an application is connected to.
If the publishing and subscribing applications
are connected to different messaging engines, the messages are being routed
via a remote queue point. On the publisher's messaging engine, click Remote
publication points and then click the publication point that represents
the subscriber's publication point. Review the number of current outbound
messages. If the number of current messages is low, the problem does not lie
with the remote message point. If the number of current messages is approaching
the high message threshold, perform the following checks: