Jenkins started and was later was not accessible for around 20 mins. During this time there were logs being pushed to jenkins.err.log.

It included logs for recurring builds getting executed successfully even thoug portal was not reachable.

One of the errors included:

Exception in thread "RequestHandlerThread37" java.lang.IllegalStateException: Internal error
at sun.security.ssl.SSLEngineImpl.initHandshaker(Unknown Source)
at sun.security.ssl.SSLEngineImpl.readRecord(Unknown Source)
at sun.security.ssl.SSLEngineImpl.readNetRecord(Unknown Source)
at sun.security.ssl.SSLEngineImpl.unwrap(Unknown Source)
at javax.net.ssl.SSLEngine.unwrap(Unknown Source)
at org.eclipse.jetty.io.nio.SslConnection.unwrap(SslConnection.java:536)
at org.eclipse.jetty.io.nio.SslConnection.process(SslConnection.java:401)
at org.eclipse.jetty.io.nio.SslConnection.access$900(SslConnection.java:48)
at org.eclipse.jetty.io.nio.SslConnection$SslEndPoint.flush(SslConnection.java:738)
at org.eclipse.jetty.io.nio.SslConnection$SslEndPoint.shutdownOutput(SslConnection.java:641)
at org.eclipse.jetty.io.nio.SslConnection.onIdleExpired(SslConnection.java:260)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint.onIdleExpired(SelectChannelEndPoint.java:349)
at org.eclipse.jetty.io.nio.SelectChannelEndPoint$2.run(SelectChannelEndPoint.java:326)
at winstone.BoundedExecutorService$1.run(BoundedExecutorService.java:77)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)