J2EE app fails StaleConnection

I have an ancient J2EE app that's started failing intermittently and rarely
with a StaleConnection. The top of the stack trace past the actual method
which fails is like so:

com.ibm.websphere.ce.cm.StaleConnectionException: Communication link
failure. (Connection was dropped unexpectedly.)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native
Method)
at
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:67)
at
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:522)
at
com.ibm.websphere.rsadapter.GenericDataStoreHelper.mapExceptionHelper(GenericDataStoreHelper.java:525)
at
com.ibm.websphere.rsadapter.GenericDataStoreHelper.mapException(GenericDataStoreHelper.java:580)
at
com.ibm.ws.rsadapter.jdbc.WSJdbcUtil.mapException(WSJdbcUtil.java:909)
at
com.ibm.ws.rsadapter.jdbc.WSJdbcStatement.executeQuery(WSJdbcStatement.java:898)

... and more.

What changed? "everything and who knows" I'm supporting a client and doing
brain surgery by telegraph here.

My question is, "assuming there is some resource limit here, is it possible
the resource limit is on the IBM i side and there is some value I can try
changing for Db2 or the host servers that will create more connections in
the pool?"