Perhaps you need to assess current memory allocations for all the JVMs in the container? You can check the config files under `/etc/default/`. So for oxAuth it will be `/etc/default/oxauth`. There will be a line like that:
JAVA_OPTIONS="-server -Xms256m -Xmx1193m -XX:MaxMetaspaceSize=512m -XX:+DisableExplicitGC -Dgluu.base=/etc/gluu -Dserver.base=/opt/gluu/jetty/oxauth -Dlog.base=/opt/gluu/jetty/oxauth -Dpython.home=/opt/jython"
`-Xms` and `-Xmx` parameters set the lowest and highest size of the JVM's heap, correspondingly. You may consider bumping it up a bit. Repeat the same procedure for other services that face memory issues. Restart each service after it's done.
Hope this helps.