jconsol indicates several blocked/waited threads.
I have been performance testing a large app which utilizes several threads and to monitor the threads I use jconsol (J2SE 5.0 Monitoring & Managament Console). For several of the threads there is indications of them having to be blocked and or waited.
I'm looking for someone that has expience in using jconsol for a large app for comparison.
About the box:
Java Virtual Machine: Java HotSpot(TM) Server VM version 1.5.0_06-b05
Vendor: Sun Microsystems Inc.
Operating System: Linux 2.6.9-42.ELsmp
Architecture: i386
Number of processors: 4
BTW we use Tomcat to manage the app.
A few examples that I have with jconsole up for ten minutes are below. I just want to know whats expected/not expected in terms of numbers. And if my numbers are to high what actions I might take to the developers or technical operations on resolving the problem.
Name: Reference Handler
State: WAITING on java.lang.ref.Reference$Lock@1bb96d2
Total blocked: 2,751 Total waited: 20,412
Stack trace:
java.lang.Object.wait(Native Method)
java.lang.Object.wait(Object.java:474)
java.lang.ref.Reference$ReferenceHandler.run(Reference.java:116)
Name: Thread-6
State: RUNNABLE
Total blocked: 281,219 Total waited: 0
Stack trace:
java.security.AccessController.doPrivileged(Native Method)
javax.xml.xpath.SecuritySupport.getContextClassLoader(SecuritySupport.java:27)
javax.xml.xpath.XPathFactory.newInstance(XPathFactory.java:143)
javax.xml.xpath.XPathFactory.newInstance(XPathFactory.java:65)
Just as an example, below I have posted all those that are blocked & waited for a 30 min. time span. To me I would think this would greatly impact performce.
Total blocked: 8 Total waited: 0
Total blocked: 3,145 Total waited: 23,435
Total blocked: 13,561 Total waited: 30,399
Total blocked: 321,495 Total waited: 0
Total blocked: 0 Total waited: 273
Total blocked: 41,499 Total waited: 8
Total blocked: 107 Total waited: 2
Total blocked: 35,671 Total waited: 5
Total blocked: 58,757 Total waited: 9
Total blocked: 1,845 Total waited: 5
Total blocked: 74,971 Total waited: 7
Total blocked: 83,228 Total waited: 11
Total blocked: 42,061 Total waited: 6
Total blocked: 62,112 Total waited: 4
Total blocked: 1,712 Total waited: 3
Total blocked: 55,679 Total waited: 8
Total blocked: 67,879 Total waited: 4
Total blocked: 64,976 Total waited: 7
Total blocked: 26,190 Total waited: 2
Total blocked: 61,375 Total waited: 8
Total blocked: 58,908 Total waited: 4
Total blocked: 29,180 Total waited: 5
Total blocked: 25,083 Total waited: 3
Total blocked: 1,098 Total waited: 2
Total blocked: 66,498 Total waited: 5
Total blocked: 66,075 Total waited: 9
Total blocked: 62,794 Total waited: 3
Total blocked: 67,218 Total waited: 12
Total blocked: 62,228 Total waited: 10
Total blocked: 66,448 Total waited: 6
Total blocked: 62,778 Total waited: 6
Total blocked: 63,787 Total waited: 7
Im not much on Java coding so please be patient with my ignorance and please explain in layments terms as best as possable. All your help is greatly appreciated. - Larry