Web Viewer Tomcat service process shows high CPU usage

Products

• Output Management Web Viewer

Issue/Introduction

The Web Viewer 12.1 Common Daemon Services Apache Tomcat service process is consistently showing high CPU i.e. consuming 92-99% CPU

Environment

Web Viewer Version:12.1.6 Build:209 (Apache Tomcat 8.5.4)

Resolution

1. An F5 load balancer for Tomcat has been implemented which is doing health check pings to Tomcat secure TCP port 443.
After removing the load balancer and its health check the high CPU symptoms for the Common Daemon Services Apache Tomcat service process was resolved.
If wanting to restore the F5 health check Web Viewer Engineering recommended increasing the previous 30 second check by 30-90 seconds to see if that would avoid the high CPU.

2. Also from directory apache-tomcat-8.5.4\logs, the cawebviewer-stderr.* and catalina.* log files show repeated exceptions:
"WARNING [https-openssl-nio-443-exec-9] org.apache.coyote.http11.Http11Processor.action Exception getting SSL attributes java.lang.IllegalStateException: SSL session ID not available".
This appears to be a Tomcat 8 specific problem and an upgrade to Tomcat 9 is recommended. The Tomcat version being used 8.5.4 was distributed with the 12.1 S1409 install so it is several years old and several Tomcat upgrade PTFs have been released since then, mainly to overcome vulnerabilities etc.
As build 209 is also over 2 years old the advice is to also upgrade Web Viewer to the latest build. 

Additional Information

See Web Viewer 12.1 Solutions page for various platforms.
Web Viewer Tomcat upgrade to 9.0.84 is now available as PTF LU12520 ("New tomcat (9.0.84) to be used with Web Viewer 12.1").