[GSS](7.4.z) Session is not getting expired even after Session timeout time. In EAP 7.4 Update 10 with JDK 1.8

Environment: JBoss EAP 7.4.10 (standalone.xml), Red Hat build of OpenJDK 1.8.0_345

Issue: the issue is when we create 500+ concurrent sessions and the Session timeout for test applications is 5 minutes. But after 5 mins we see that some of the sessions was not expired which was suppose to expire. 

In the screenshot [img_jdk8.png] I created 600 concurrent sessions but after 5 mins i can see 587 sessions was expired but 13 connections were active which was suppose to expire after 5 mins. 

Steps to reproduce:

• start eap 7.4.10 with JDK 1.8 in standalone mode
• deploy the attached ear file
• create 600 concurrent sessions. To do this you can use curl command as below:

  for i in {1..600}; do curl http://127.0.0.1:8080/subapp1/; done

• Then open the JBoss admin console Runtime->web->Deployment->Click on any deployment as shown in in the screenshot and enable statistics
• Wait for 5 mins and you will see that some of the sessions was still active which was suppose to expire after 5 mins.

Note: This issue is not happening in JDK 11(check screenshot  [img_jdk11.png] ). Using JDK11 and JBoss EAP 7.4.10 all the sessions is getting expired after 5 mins as expected.