Sometimes you notice that SOA BPEL transactions are not evenly balanced between different nodes in a SOA Cluster. Symptoms of this issues are un-even SOA Datasource connection counts and system utilization (CPU/Mem). You can run the below query to find out how the BPEL transactions are load balanced between different soa servers in a cluster.
SELECT ‘BPEL’, create_cluster_node_id, COUNT(*), max(creation_date), min(creation_date ) FROM soa_soainfra.cube_instance where creation_date between ‘30-JUN-2016 8:30‘ and ‘30-JUN-2016 12:30‘ GROUP BY create_cluster_node_id
In the above case, the transactions are pretty evenly balanced. By default, SOA composite invokes another SOA composite within the same Weblogic (WLS) server bypassing the whole SOAP stack, and makes a direct java call (RMI) to optimize the invocation. This works great in terms of performance but it can cause some uneven load balancing of the transactions specially when using FTP and File Adapters. If you do see an uneven load, you can make the below changes in composite.xml to turn off the local optimization.