ADDITIONAL SYSTEM INFORMATION :
Java 11.0.8

A DESCRIPTION OF THE PROBLEM :
Lot many threads are in RUNNABLE STATE and doesn't come out in
  java.lang.Thread.State: RUNNABLE
        at java.net.Inet4AddressImpl.lookupAllHostAddr(java.base@11.0.8/Native Method)
Few threads are getting blocked
   java.lang.Thread.State: BLOCKED (on object monitor)
        at java.net.InetAddress$NameServiceAddresses.get(java.base@11.0.8/InetAddress.java:832)

REGRESSION : Last worked in version 11

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
When ever we get an DNS Resolution issue which throws UnknownHostException after some time the threads are getting blocked and we need to restart the system

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The system should not be paused or blocked and once the DNS resolution is proper the system should become stable

FREQUENCY : often