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Duke · Posted: Tue Dec 18, 2007 3:25 am Post subject:

Hi,

I have a message flow which reads +- 17200 records from an oracle database in a compute node using a single query.
For each record retrieved from the database, it creates an XML outputmessage (size <= 2 kb) that is propagated downstream the flow where there is a MQJMSTransform node which in turn puts it on a JMSOutput queue.
The flow is being triggered by one inputmessage. When I launch this flow, it retrieves the records from the database. After it has only outputted +- 1500 messages on the JMSOutputqueue the execution group crashes because of a memory abend (failed to allocate memory).

When I changed the JMSOutput node to an MQOutput node and added a JMSMQTransform node I still received the abend. However if I remove the two transformation nodes, all records are processed without any problem.

I have traced the memory for the execution group. In the case of a JMSMQTransform node it rapidely increases untill it is maxed out. Without JMSMQTransform node it remains stable all the time (and uses significantly less memory).

The settings of the nodes:

MQInput Node:
- Transaction Node: No.

Compute Node:
- Transaction: Automatic
- Compute mode: Message
- I have assigned the result of the query to a variable in the Environment. And for each records I issue a propagate (just "PROPAGATE") after I have filled in all the fields of the OutputRoot.

JMSOutput Node:
- Transaction Node: None.

MQOutput Node:
- Transaction Node: No.

In the ESQL of the while loop I have added the statement 'DELETE FIELD OutputRoot.XML/MRM' to clear memory, but that did not help.

I have increased the heapsize of the JVM, but that did not help either.

Hope that you can help us!

_________________
Pierre Richelle

Engineer
IBM Certified MQSeries Developper V5.3
IBM Certified WMQ Administration V6