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Last modified by David Avendasora on 2010/11/30 06:43
From version 12.1
edited by Pascal Robert
on 2007/09/03 22:05
Change comment: There is no comment for this version
To version 15.1
edited by David Avendasora
on 2010/11/30 06:42
Change comment: There is no comment for this version

Summary

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Title
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1 -Web Applications-Deployment-Debugging Frozen Deployed Instances
1 +Troubleshooting Frozen Deployed Instances
Author
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1 -XWiki.probert
1 +XWiki.avendasora
Content
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56 56  
57 57  Now restart your instances.
58 58  
59 +Note that some JVM's on other platforms expect the "jdwp" to be specified as follows;
60 +
61 +{{noformat}}
62 +
63 +-agentlib:jdwp=transport=dt_socket,address=8121,server=y,suspend
64 +
65 +{{/noformat}}
66 +
59 59  = When Something Goes Wrong... =
60 60  
61 61  The instances are listed in the JavaMonitor. A screenshot is shown below with the instance number circled in red. You need to first identify which instance has frozen.
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86 86  
87 87  = What to Look For =
88 88  
97 +##jdb##'s ##watch all## command will give you a stack trace for all threads in your app. But your process needs first to be suspended in order to get a coherent stack trace. Use it like so:
98 +
99 +{{noformat}}
100 +
101 +> suspend
102 +All threads suspended.
103 +> where all
104 +...
105 +> resume
106 +All threads resumed.
107 +>
108 +
109 +{{/noformat}}
110 +
89 89  An example of a stack trace is shown below. You'll notice the java class name and source-code line number at the end of a particular entry in the stack. Here we can see that the thread called "WorkerThread103" has stuck trying to get a session from the session store. In this situation another thread will most likely have the session store locked and is not releasing the lock.
90 90  
91 91  {{noformat}}
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120 120  = Conclusion =
121 121  
122 122  Despite the simplicity of this approach, it provides for a means by which you can find out what is going on inside frozen instances rather than playing laborious guessing games.
145 +
146 += Alternative Approaches =
147 +
148 +[[http://www.gvcsitemaker.com/gvc.webobjects/faq&mode=single&recordID=41413]]