[virgo-dev] class loaders in context.xml

[Saadat Dowlati <sdowlati@xxxxxxxxxxxxxx>]

Hello,

       We have become very interested in VWS and are trying to migrate our application from Tomcat. As the first step, following the documentation, I dropped our application WAR (which works on Tomcat 6) in the pickup directory. According to the log, VWS installs the WAR, but fails to start it.

The error messages don't provide any hint as to the root cause: 

[2010-11-14 16:12:05.472] fs-watcher                   <HD0001I> Hot deployer processing 'CREATED' event for file 'EMA-Server.war'.

[2010-11-14 16:12:06.122] fs-watcher                   <DE0000I> Installing bundle 'EMA-Server' version '0.0.0'.

[2010-11-14 16:12:09.285] fs-watcher                   <DE0001I> Installed bundle 'EMA-Server' version '0.0.0'.

[2010-11-14 16:12:09.311] fs-watcher                   <DE0004I> Starting bundle 'EMA-Server' version '0.0.0'.

[2010-11-14 16:12:09.316] Thread-3                     <WE0000I> Starting web bundle 'EMA-Server' version '0.0.0' with context path '/EMA-Server'.

[2010-11-14 16:12:14.696] Thread-3                     <WE0005E> Failed to start web bundle 'EMA-Server' version '0.0.0': consult the serviceability log for further details.

[2010-11-14 16:12:14.701] start-signalling-4           <DE0006E> Start failed for bundle 'EMA-Server' version '0.0.0'. org.eclipse.virgo.kernel.deployer.core.DeploymentException: W

eb application failed to start

        at org.eclipse.virgo.web.core.internal.WebBundleLifecycleListener.onStarted(WebBundleLifecycleListener.java:129)

        at org.eclipse.virgo.kernel.install.artifact.internal.ArtifactStateMonitor.onStarted(ArtifactStateMonitor.java:205)

        at org.eclipse.virgo.kernel.install.artifact.internal.AbstractInstallArtifact.asyncStartSucceeded(AbstractInstallArtifact.java:273)

        at org.eclipse.virgo.kernel.install.artifact.internal.AbstractInstallArtifact.access$0(AbstractInstallArtifact.java:270)

        at org.eclipse.virgo.kernel.install.artifact.internal.AbstractInstallArtifact$StateMonitorSignal.signalSuccessfulCompletion(AbstractInstallArtifact.java:223)

        at org.eclipse.virgo.kernel.core.internal.BundleStartTracker$1.run(BundleStartTracker.java:140)

        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)

        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)

        at java.lang.Thread.run(Thread.java:619)

Caused by: org.eclipse.gemini.web.core.WebApplicationStartFailedException: org.eclipse.gemini.web.core.spi.ServletContainerException: Web application at '/EMA-Server' failed to sta

rt. Check the logs for more details.

        at org.eclipse.gemini.web.internal.StandardWebApplication.start(StandardWebApplication.java:107)

        at org.eclipse.virgo.web.core.internal.WebBundleLifecycleListener.onStarted(WebBundleLifecycleListener.java:120)

        ... 8 common frames omitted

Caused by: org.eclipse.gemini.web.core.spi.ServletContainerException: Web application at '/EMA-Server' failed to start. Check the logs for more details.

        at org.eclipse.gemini.web.tomcat.internal.TomcatServletContainer.startWebApplication(TomcatServletContainer.java:123)

        at org.eclipse.gemini.web.internal.StandardWebApplication.start(StandardWebApplication.java:90)

        ... 9 common frames omitted 

 

While searching in the documentation, I came across the following note. It got my attention, as we use the TomcatInstrumentableClassLoader in the Tomcat's context.xml packaged in our WAR file.

Note that the following context configuration features are not supported in Virgo Web Server:

• Custom class loaders

 Is TomcatInstrumentableClassLoader  considered a "Custom class loader" in VWS? If yes, is there any workaround for it? Here's the line from our context.xml file:

 

 <Loader

  loaderClass="org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader"

  useSystemClassLoaderAsParent="false" />

Thanks in advance,

--

sd