MQSeries.net :: View topic - SAPRequest adapter: 2nd msg fails, JCo Session Ref is NULL

northwilks · Posted: Mon Feb 11, 2013 8:36 pm Post subject:

Using WBI Message Broker v7 to send message thru SAPRequest node creating SAP Idoc.
Broker is running on Windows XP machine with SAP ERP 6.0 running on AIX.

First message sent thru flow after the deployment to execution group is successful. IDoc created at target SAP box meets all expectations.

Second message sent thru same node fails. Exception message passed out the 'failure' path. Last child contains message:
"Session reference is null. SessionReferenceProvider: com.ibm.j2ca.sap.ext.JCo3SessionReferenceProvider, scope type: null\r\n"

If execution group is redeployed, again, first message works fine. Second message fails.
A third message may succeed. But next one will fail for certain. Pattern not steady but close.

I stopped the flow in debug, details of the messages just prior to SAPRequest seem consistent.
On SAP side, I see the broker execute an ALE call for all the successful messages but no sign of any activity when processing a message that fails. The error seem to indicate that the broker attempted to establish or use a SAP session but SAP returned a NULL for session refernece ID? Maybe something did not release from SAP on preceding message so following message gets blocked?
I did change the setting on adapter for 'Reset JCO Client after closing connection handle' because that sounded like a potential fix. No effect.

I ran a user trace for both a succesful and unsuccesful thread to compare, it did not offer any insight. It seemed to fail immediately on first contact with SAP (during unsuccessful attempt). My search of SAP notes did not highlight known fails in a way that I could identify.

I'm more likely to suspect a mistake on my part then either SAP JCo or WMB issue but any recomendations on how I could narrow it down would be great.