High application time in GC Log

Question

Mystery in GC LOG - Application Time.

GC LOG contains more details and there is found "Application time" field and 83 Seconds was there. In that time server was active and suddenly a gap of 83 seconds found to be empty and there are no GC activities and no requests were accepted by the server and those requests were put in the TCP_Accept_Queue.

For 83 seconds the server didn't accepted and requests and already serving requests were hanged and then served after the 83 second gap.

The GC LOG looked like this.

2019-08-27T19:37:08.328+0530: 7101.614: Total time for which application threads were stopped: 0.0534706 seconds, Stopping threads took: 0.0004376 seconds
2019-08-27T19:38:31.713+0530: 7185.000: Application time: 83.3856673 seconds
2019-08-27T19:38:31.719+0530: 7185.005: Total time for which application threads were stopped: 0.0054572 seconds, Stopping threads took: 0.0032875 seconds

Need to know where exactly the 83 seconds spent by that application server.