This week's giveaway is in the Android forum.
We're giving away four copies of Android Security Essentials Live Lessons and have Godfrey Nolan on-line!
See this thread for details.
The moose likes JSP and the fly likes Unbalanced process load ?? one java process is locked to highest CPU load ?? Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login


Win a copy of Android Security Essentials Live Lessons this week in the Android forum!
JavaRanch » Java Forums » Java » JSP
Bookmark "Unbalanced process load ?? one java process is locked to highest CPU load ??" Watch "Unbalanced process load ?? one java process is locked to highest CPU load ??" New topic
Author

Unbalanced process load ?? one java process is locked to highest CPU load ??

Huang Teng Shiu
Greenhorn

Joined: Aug 11, 2002
Posts: 5
I am using resin 2.1.6 on RedHat 7.3 on a P4-2G box with 1GB RAM.

We all know that resin will 'fork' a lot of java process to handle JSP/servlet requests.
Generally , these process have similar CPU load , each about lower than 5% of CPU load,
and no process will always occupy highest CPU load, for example :

BUT , sometimes (about two or three times per day), there will be one process 'locked' to highest CPU load , forever !
This is the case :

We see that PID 2667 occupies highest extraordinary CPU load , and it will never go down....and maybe goes up to 80% to 90% CPU load !!!
The JSP/servlet pages begin slow down , and the system load will go higher and higher.
Finally , it will cause javax.servlet.jsp.JspException
This is the result dumped to the error.log :

[2002/12/27 17:22:15] null
javax.servlet.jsp.JspException
at org.apache.taglibs.standard.tag.common.core.ImportSupport.acquireString(ImportSupport.java:324)
at org.apache.taglibs.standard.tag.common.core.ImportSupport.doEndTag(ImportSupport.java:179)
at _jsp._SomePage__jsp._jspService(_SomePage__jsp.java:86)
at com.caucho.jsp.JavaPage.service(JavaPage.java:75)
at com.caucho.jsp.Page.subservice(Page.java:497)
at com.caucho.server.http.FilterChainPage.doFilter(FilterChainPage.java:182)
at com.caucho.server.http.Invocation.service(Invocation.java:312)
at com.caucho.server.http.CacheInvocation.service(CacheInvocation.java:135)
at com.caucho.server.http.RunnerRequest.handleRequest(RunnerRequest.java:342)
at com.caucho.server.http.RunnerRequest.handleConnection(RunnerRequest.java:272)
at com.caucho.server.TcpConnection.run(TcpConnection.java:137)
at java.lang.Thread.run(Thread.java:536)

The error can not be automatically fixed!
Even I add <jsp recompile-on-error='true'/> in web.xml cannot solve the problem.

All I have to do is restart the webapp manually....and if I am not beside the terminal , then the error will never be recovered.

I don't think it's related to the size of concurrent online users. Because sometimes there will be more users and processes (In the midnight , sometimes up to 170+ processes) , and the server load is still low and the web site is very fluent.

Can somebody tell me what to do ? Thanks in advance ....
[ December 27, 2002: Message edited by: Huang Teng Shiu ]
 
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.
 
subject: Unbalanced process load ?? one java process is locked to highest CPU load ??
 
Similar Threads
Tomcat Memory Usage too Large(Urgent!!!)
Can Not Keep Tomcat Up and running ~30 mins
back ground process id ??
How to capture diagnostics output continuously
liferay tomcat running slow on linux