RE: Enhydra Multiserver Bug?

Hi Charles,

I'm not one of the Enhydra contributors, but..

It's hard to see what's going on here, but could it be that a class that is 
used by the PCP initialization is missing?

I wonder if your Pcp.startup() method is referencing a class that is missing or 
can not be loaded due to a conflict with another class..

Or perhaps there is a field in your Pcp class that can not be created because 
the class can't be found.

Something like
public class Pcp extends StandardApplication { 
   SomeClass  myVariable
// Is SomeClass in you class path?
// or Does SomeClass reference another class that is _not_ in your Classpath?
}

Class loading problems are a big pain for any Java application / or app server..
Sometimes the Java exceptions are not very helpful.

Version conflicts are also hard to debug.  For example you may have another 
version of a set of classes in you classpath.  If you have a lot of jars in 
your path, you may need to list the contents of some of them to see if the same 
classes exist elsewhere.. This can cause conflicts, and class-cast exceptions 
etc.

Just guessing..  
Mike.

-----Original Message-----
From: Charles Rector [mailto:crector@xxxxxxxxxxxxx]
Sent: Tuesday, October 22, 2002 8:35 AM
To: enhydra@xxxxxxxxxxx
Subject: Enhydra: Enhydra Multiserver Bug?


Hi, I'm hoping some of the Enhydra developers might be able to look at this
because it seems like it might be a bug:

Since posting my last message to this list ("Multiserver, Error: 500
Internal Servlet Error"), I tried relocating my application to another
server. This time around I'm not even able to Start the application. The
most confusing thing is, the multiserver log dumps somewhat contradictory
error messages when running in debug mode as opposed to when running with no
debugging. It reports it cannot find a class without debugging info, but
that it can find the class with debugging info turned on:

Without debugging info:

2002.10.22 05:52:51: Multiserver,INFO: Starting servlet/application pcp
2002.10.22 05:52:51: Multiserver,INFO: Application pcp has url prefix
"/pcp".
2002.10.22 05:52:51: pcp,INFO: pcp: init
2002.10.22 05:52:51: Multiserver,ERROR: Initialization of application
failed: pcp.pcp
2002.10.22 05:52:51: Multiserver,ERROR+ java.lang.ClassNotFoundException:
pcp.pcp
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.classloader.MultiClassLoader.doLoadClass(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.classloader.MultiClassLoader.loadClassResource(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.classloader.MultiClassLoader.loadClass(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
java.lang.ClassLoader.loadClass(ClassLoader.java:255)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.server.httpPresentation.servlet.HttpPresentationServlet
.initApplication(Unknown Sour$
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.server.httpPresentation.servlet.HttpPresentationServlet
.init(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.ServletWrapper$2.method(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.ServletWrapper.handleInvocation(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.ServletWrapper.loadServlet(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.Context.loadServlets(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.Context.setupLoadableServlet(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.enhydra.servlet.servletManager.ServletManager.start(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.admin.presentation.Perform.performAction(Perform.java:7
6)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.admin.presentation.Perform.runPage(Perform.java:151)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.server.jolt.joltpo.JoltPage.run(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.server.httpPresentation.HttpPresentationManager.runPres
entationObj(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.server.httpPresentation.HttpPresentationManager.Run(Unk
nown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.server.httpPresentation.servlet.HttpPresentationServlet
.serviceDirect(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
com.lutris.appserver.server.httpPresentation.servlet.HttpPresentationServlet
.service(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.ServiceInvocationHandler.method(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.ServletWrapper.handleInvocation(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.ServletWrapper.handleRequest(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.apache.tomcat.core.Context.handleRequest(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.enhydra.servlet.servletManager.ServletManager.service(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.enhydra.servlet.connectionMethods.http.HttpHandler.doARequest(Unknown
Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.enhydra.servlet.connectionMethods.http.HttpHandler.processRequests(Unkno
wn Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
org.enhydra.servlet.connectionMethods.http.HttpHandler.run(Unknown Source)
2002.10.22 05:52:51: Multiserver,ERROR+         at
java.lang.Thread.run(Thread.java:536)
2002.10.22 05:52:51: pcp,ERROR: cannot load servlet name: pcp

With class-loading debug info:

2002.10.22 06:05:56: Multiserver,CLASSLOAD: class loaded by: parent
2002.10.22 06:05:56: Multiserver,INFO: Starting servlet/application pcp
2002.10.22 06:05:56: Multiserver,DEBUG: initContext() servletID=pcp
context=org.apache.tomcat.core.Context@10f6d3 path=/pcp url=file:/.
2002.10.22 06:05:56: Multiserver,INFO: Application pcp has url prefix
"/pcp".
2002.10.22 06:05:56: pcp,INFO: pcp: init
2002.10.22 06:05:56: Multiserver,DEBUG: Loaded Enhydra application: pcp.pcp
2002.10.22 06:05:56: Multiserver,DEBUG:     presentation prefix:
pcp/presentation
2002.10.22 06:05:56: Multiserver,DEBUG:     Class path:
/usr/local/enhydra5.0/lib/pcp/pcp-20021021-1748.jar,
/usr/local/enhydra5.0/lib, /usr/local/java/iexp$
2002.10.22 06:05:56: Multiserver,CLASSLOAD: loadClass: pcp.pcp
2002.10.22 06:05:56: Multiserver,CLASSLOAD: checking parent class loader:
pcp.pcp
2002.10.22 06:05:56: Multiserver,CLASSLOAD: class not loaded by parent:
pcp.pcp: java.lang.ClassNotFoundException: pcp.pcp
2002.10.22 06:05:56: Multiserver,CLASSLOAD: checking MultiClassLoader:
pcp.pcp
2002.10.22 06:05:56: Multiserver,CLASSLOAD: getResource loading:
pcp/pcp.class
2002.10.22 06:05:56: Multiserver,CLASSLOAD:   checking:
"/usr/local/enhydra5.0/lib/pcp/pcp-20021021-1748.jar"
2002.10.22 06:05:56: Multiserver,CLASSLOAD:   found: pcp/pcp.class
2002.10.22 06:05:56: Multiserver,CLASSLOAD: getResource finished:
pcp/pcp.class
...


As you can see the pcp.pcp class was not found while running without
debugging info, whereas with debugging info it was. In either case, the
application does not Start from the admin. Is this a multiserver bug?
Neither I, nor my fellow employees, can think of any reason why this should
be happening.

--
Chuck Rector
Internet Exposure, Inc.
http://www.iexposure.com
crector@xxxxxxxxxxxxx

Web Development - Web Marketing - ISP Services
(612) 676-1946

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