commons-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Taras Tielkes (JIRA)" <j...@apache.org>
Subject [jira] Updated: (LOGGING-108) Classloader reference leak on Tomcat 5.5.17 with log4j in webapp
Date Tue, 27 Jun 2006 18:56:30 GMT
     [ http://issues.apache.org/jira/browse/LOGGING-108?page=all ]

Taras Tielkes updated LOGGING-108:
----------------------------------

    Attachment: path.gif

Screenshot from commercial JVMTI tool (YourKit) showing the reference graph from a GC, through
the leak described, to the user deployed classes.

JVMTI memory snapshot was taken after application undeployment (otherwise you see more GC
roots)

> Classloader reference leak on Tomcat 5.5.17 with log4j in webapp
> ----------------------------------------------------------------
>
>          Key: LOGGING-108
>          URL: http://issues.apache.org/jira/browse/LOGGING-108
>      Project: Commons Logging
>         Type: Bug

>     Versions: 1.1 Final
>  Environment: JDK 1.5.0_07, Tomcat 5.5.17
> commons-logging-api-1.1.jar is configured for the Tomcat bootstrap
> commons-logging-adapters-1.1.jar is deployed with a webapp
> log4j-1.2.11 is deployed with webapp
> This is the configuration specifically described in the release notes for 1.1:
> " New jar file commons-logging-adapters-xxx.jar is now provided. This can be
>   used to resolve class cast conflicts where parts of commons-logging are
>   deployed via different classloaders. It is not expected to be frequently
>   used; it is only necessary in situations where a container has deployed
>   commons-logging-api.jar and a webapp wants to bind to a third-party
>   logging implementation such as log4j. In this case, the webapp can
>   experience problems if it deploys commons-logging.jar as this causes
>   duplicates of the core commons-logging classes, but commons-logging-adapters
>   can be safely used."
>     Reporter: Taras Tielkes
>  Attachments: path.gif
>
> Some Tomcat Jasper implementation classes are initialized (that mean static fields and
static initializer) when the current thread has the webapp classloader set as the context
classloader.
> An example of this is org.apache.jasper.runtime.PageContextImpl
> If the first JSP page rendered on a freshly started Tomcat 5.5.17 is for a webapp that
contains the configuration described in the "Environment" section above, a leak will occur:
> The class PageContextImpl (loader by CL above Webapp classloader in delegation chain)
stays loaded for the duration of the JVM
> The "log" field in this class refers to a class loaded from a WebappClassloader.
> This produces a classloader reference leak to the webapp, even after undeployment.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
   http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see:
   http://www.atlassian.com/software/jira


---------------------------------------------------------------------
To unsubscribe, e-mail: commons-dev-unsubscribe@jakarta.apache.org
For additional commands, e-mail: commons-dev-help@jakarta.apache.org


Mime
View raw message