Our environment is WPS 7.0, with cluster of 4 nodes and backend is Oracle.
We had recently experienced frequent heap dumps on heavy load and reported lot of sessions getting blocked from Oracle,
The heapdump snapshot (from heap analyzer) showed JTA Implementation classes and Connection pool were primary suspects. (oracle.jdbc.driver.T2CStatement com/ibm/ws/tx/jta/TransactionImpl,com/ibm/ejs/util/Bucket , com.ibm.ejs.j2c.MCWrapper are found to be the primary suspects)
Further debugging revealed that Two nodes were loading JDBC Drivers from different path (OJDBC5.jar) and two nodes were loading JDBC Drivers from Oracle Client (OJDBC6.jar). JDBC Driver Provider path(s) and jar files configured in WPS were different. Note - It was done through WAS environment variables which were pointing to different directories in different nodes.
I'm not sure whether this can cause different behavior in connection pools etc., paritcularly in WPS cluster of 4 nodes.
Just wanted to know if this can be primary cause for leak ? Are there any known problems with connection pools of different JDBC driver versions.