SAP can be installed on single or on multiple Java instances. A SiteMinder ERP agent can be installed on it and a Webagent at the Front End. When we use a multiple Java instances, ERP Agent fails to handle headers properly and and log "TransactionID header not found or empty - Aborting" Architecture:
SAP in cluster with 2 Java instances. The sap portail uses the session affinity.
When we switch from 1 instance to the other it seems that HTTP headers are lost.
CA has certified and tested the ERP agent with SAP Server having single AS Java server instance. Hence CA doesn't support this combination.