IdP Java OutOfMemoryError

[Bryan K. Walton]

This morning, our IdP, running 4.0.1 on CentOS 8 (JDK 11), threw a Java
Out of Memory Error:

Sep 17 11:00:45 idp java[610134]: Exception: java.lang.OutOfMemoryError thrown from the UncaughtExceptionHandler in thread "qtp762218386-30247"

About this time, the IdP quit responding to authentication requests. The
system had plenty of system memory free, at this time.  A restart of the
shibboleth-idp service restored things to working order.

One thing to note, our IdP is not downloading InCommon's metadata.  Does
anybody have any suggestions for how we can/should prevent this out of
memory error?  

When I run:
java -XX:+PrintFlagsFinal -version | grep -iE 'HeapSize|PermSize|ThreadStackSize'

It shows that our InitialHeapSize is 60MB. And our MaxHeapSize is 944MB.

Thanks,
Bryan