high CPU Usage in Vaadin8

General
1

Hello,

after our last deployment in production we have a strange issue with the cpu usage in the jvm.
It raises to 100% for hours…

Here is a Stacktrace out of AppDynamics:
Thread Name:http-nio-8080-exec-71 ID:183 Time:Mon Mar 30 08:19:59 CEST 2020 State:WAITING Priority:5 sun.misc.Unsafe.park(Native Method) java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836) java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:870) java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1199) java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:209) java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:285) com.vaadin.server.VaadinService.lockSession(VaadinService.java:703) com.vaadin.server.VaadinService.findOrCreateVaadinSession(VaadinService.java:739)

It seems, that there is a problem with the session? The /vaadinServlet/UIDL/ sometimes tooks more than 20 minutes.
But the application is as smooth as every day :slight_smile:

Did anybody had the same problem and resolved it?

Regards,
Michael Lanser

2

I just figured out, that such a Sever has also a problem when we try to restart it:

Waiting for [200]
instance(s) to be deallocated for Servlet [springVaadinServlet]

I try to get some information out of the internet…