Thread leakage in JCS 3.1 with primary and secondary server configuration

We are using Apache JCS as a primary cache server in our application. The version we are using is apache-commons-jcs3 3.1. On production environment we have observed that this specific version is having a thread leakage issue where on the production servers, the thread count is increasing rapidly and reaching 20000 threads, and the system crashes due to the OutOfMemory error. It is observed while degrading the JCS version from 3.1 to 3.0. The problem is no longer reproducible. With the JCS 3.1 version we have also tried implementing thread pooling, but it did not solve the problem .

Steps to reproduce -

1) JCS configured to have primary and failover server

Please refer cache.ccf configurations attached

Check thread count via command

ps -o pid,comm,user,thcount -p <PID>

2) Restart Primary server

After certain usage by JCS client check the thread count via below command

ps -o pid,comm,user,thcount -p <PID>