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From "Ate Douma (JIRA)" <jetspeed-...@portals.apache.org>
Subject [jira] Resolved: (JS2-541) Log initialization failures when deploying on Websphere 6.0.2.x
Date Thu, 08 Jun 2006 14:33:30 GMT
     [ http://issues.apache.org/jira/browse/JS2-541?page=all ]
Ate Douma resolved JS2-541:

    Resolution: Fixed

Fixed (although maybe better called a workaround for the nasty WAS 6.0.2.x classloader bug)

> Log initialization failures when deploying on Websphere 6.0.2.x
> ---------------------------------------------------------------
>          Key: JS2-541
>          URL: http://issues.apache.org/jira/browse/JS2-541
>      Project: Jetspeed 2
>         Type: Improvement

>   Components: Components Core
>     Versions: 2.1-dev
>  Environment: Ubuntu 6.0.6, Websphere Application Server 6.0.2.x
>     Reporter: Ate Douma
>     Assignee: Ate Douma
>     Priority: Blocker
>      Fix For: 2.1, 2.1-dev

> Websphere 6.0.2.x has a mighty annoying classloader bug which prevents the JetspeedServlet
to initialize.
> When Websphere bootstraps a web application, it uses *not* the (properly) created web
application classloader (configured with PARENT_LAST)
> but its own com.ibm.ws.bootstrap.ExtClassLoader (which defaults to PARENT_FIRST) for
class initializing (<clinit>) the servlet.
> Note: the correct web application classloader *is* used to initialize the servlet itself
(method init(ServletConfig)), but not the static
> class initialization (<clinit>).
> And, starting (again) the portal through the WAS admin console, exposes a similar classloader
bug. This time, not the bootstrap.ExtClassLoader
> is set as context ClassLoader but the *console* app classloader during class initialization!
> We currently have two static initialized Commons Logging Log members defined in the JetspeedServlet.
> Furthermore, through the jetspeed-webapp-logging component, we setup a custom Log implementation
(IsolatedLog4JLogger) which Commons Logging
> picks up from the commons-logging.properties resource file (contained within the jetpeed-webapp-logging
> But, WebSphere 6.0.2.x (and maybe even 6.0 but I haven't checked that one) also provides
such a commons-logging.properties resource contained within
> the ws-commons-logging.jar from the globally shared lib directory.
> In it, it defines: 
>   org.apache.commons.logging.Log=org.apache.commons.logging.impl.Jdk14Logger
> Note: this wasn't the case yet in WAS 5!
> Now, because of the above described classloader bug (e.g. a PARENT_FIRST bootstrap classloader)
during static initialization of the JetspeedServlet, 
> Commons Logging will *not* see the commons-logging.properties resource as provided by
our jetspeed-webapp-logging jar but load it from the global
> ws-commons-logging.jar.
> Problem:
>   org.apache.commons.logging.LogConfigurationException: org.apache.commons.logging.LogConfigurationException:

>     org.apache.commons.logging.LogConfigurationException: Class org.apache.commons.logging.impl.Jdk14Logger
does not implement Log
>         at org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:532)
>         at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:272)
>         at org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:246)
>         at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:395)
>         at org.apache.jetspeed.engine.JetspeedServlet.<clinit>(JetspeedServlet.java:61)
>         ... 25 more
> A quick workaround would be removing the Log definition from the commons-logging.properties
in ws-commons-logging.jar.
> Better yet: IBM should fix this classloader bug!
> But luckily (in this situation) the JetspeedServlet can be modified such that this problem
won't occurr: 
> I'm going to move the initialization of the static Log instances in JetspeedServlet to
the init(ServletConfig).
> When that method is invoked by WAS, it is done with the proper context ClassLoader and
Log initialization uses our IsolatedLog4JLogger again.
> And then, after I fixed this, another classloader problem popped up!
> JetspeedServlet also implements HttpSessionListener which it uses for closure of PortalStatistics
logging when a user logs out.
> Now, it turns out WAS 6.0.2.x calls the Servlet.destroy() method *before* calling sessionDestroyed(HttpSessionEvent)
for existing sessions!
> It seemingly does so (again) with an incorrect context classloader.
> In our JetspeedServlet.sessionDestroyed() implementation we try to access the PortalStatistics
component from the SpringComponentManager.
> But, as the JetspeedEngine (and thus the ComponentManager) have already shutdown because
JetspeedServlet.destroy() has already been called,
> Spring is going to reload its configuration. And, as it wants to logs some info messages
doing that, its going to (re)initialize Commons Logging
> again too (which also already was shutdown through the Log4JConfigurator ContextListener).
> And there it is again, same exception as shown above: Jdk14Logger does not implement
Log :(
> So, I've also modified the JetspeedServlet.sessionDestroyed() method which will skip
PortalStatistics closure logging when the destroy() method
> has been called already.
> A last remark for anyone wanting to deploy a Jetspeed based portal on WAS and has dependencies
on xerces, xalan and xml-apis for its
> portlet applications (just as Jetspeed itself has). 
> You need to move these three jars (as well as the other already required shared libs)
inside the ear *besides* the war files, define a Class-Path
> entry in each war file META-INF/MANIFEST.MF referencing these "shared" libs, and remove
these three jars from your war WEB-INF/lib folder.
> This is standard shared library ear file packaging, check the J2EE docs for further information.
> And finally: make sure to change the default WAS Class Loader Mode to PARENT_LAST for
your portal ear *and* each of its contained (portlet) web applications.

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