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Problem(Abstract) |
Collecting data for problems with the IBM® WebSphere®
Application Server Classloader component. Gathering this information
before calling IBM support helps familiarize you with the troubleshooting
process and saves you time. |
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Resolving the
problem |
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If you already contacted support, continue to the component-specific
MustGather information. Otherwise, click: MustGather:
Read first for all WebSphere Application Server products.
Collecting Classloader specific MustGather information
This technote explains the information needed to better understand when
WebSphere Application Server fails to load classes or resources. If you
are receiving one of the following common classloader errors or
exceptions, you will need to gather the following version specific
information:
- ClassNotFoundException
- NoClassDefFoundError
- ClassCastException
Application code diagnostics ClassCastExceptions:
Modify client code to output the classloader of cast target class, the
classloader of the cast source object class, and the context classloader
immediately before the point of failure. Example code is below:
// For a cast such as
"(TargetClass)sourceObject", add the
// following lines before the cast statement:
ClassLoader ctxCL =
Thread.currentThread().getContextClassLoader();
ClassLoader tcCL = TargetClass.class.getClassLoader();
ClassLoader soCL = sourceObject.getClass().getClassLoader();
System.out.println("ctxCl=" + ctxCL);
System.out.println("tcCl=" + tcCL);
System.out.println("soCl=" + soCL);
This document is split up into two sections, depending on your version of
Application Server:
WebSphere Application Server V6.0
and V6.1 specific information
Perform the following steps:
- Enable classloader tracing using the following string:
- Enable Java™ Virtual Machine (JVM) classloader and bootstrap traces
through the administrative console for Version 6.0:
- Expand Servers, choose Application servers and select
the problem server.
- On right side, under Server Infrastructure expand Java and
Process Management.
- Click Process Definition.
- Under Additional Properties, select Java Virtual
Machine.
Enable the following Properties by selecting the check boxes on the left
of the property.
- Verbose class loading
- Verbose JNI
- Click Apply.
- On right side, under Additional Properties click Custom
Properties.
- Click New.
- Enter the following custom property:
- Name: ws.ext.debug
- Value: true
- Click OK.
- Save the changes.
- Restart the server.
- Recreate the classloader issue.
- Run the collector tool against the problem profile:
- Send us the Enterprise Application and the collector output.
- Follow instructions to send
diagnostic information to IBM support.
WebSphere Application Server V5.0 and
V5.1 specific information
Perform the following steps:
- Enable classloader tracing using the following string:
- Enable Java Virtual Machine (JVM) classloader and bootstrap traces
through the administrative console for V5.0 and V5.1:
- Expand Servers, choose Application servers and select
the problem server.
- Under Additional Properties, click Process Definition.
- Under Additional Properties, select Java Virtual
Machine.
Enable the following Properties by selecting the check boxes on the left
of the property.
- Verbose class loading
- Verbose JNI
- Click Apply.
- Under Additional Properties click on Custom Properties.
- Click New.
- Enter the following custom property:
- Name: was.ext.debug
- Value: true
- Click OK.
- Save the changes.
- Restart the server.
- Recreate the classloader issue.
- Run the collector tool:
- Send us the Enterprise Application and the collector output.
- Follow instructions to send
diagnostic information to IBM support.
What to do next
Once you have collected the preceding information, you can begin
Analyzing the data or simply send
the diagnostic information to IBM support. |
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Cross Reference information |
Segment |
Product |
Component |
Platform |
Version |
Edition |
Application Servers |
WebSphere Application Server - Express |
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AIX, HP-UX, Linux, Solaris, Windows |
6.1, 6.0, 5.1, 5.0 |
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Application Servers |
Runtimes for Java Technology |
Java SDK |
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