Re: Commons logging and memory leaks

Wed, 18 May 2005 03:21:34 -0700 

Hi Simon,

Thanks for your answer.
See my comments below....

Simon Kitching wrote:


Firstly, I presume you mean commons-logging-1.0.5-alpha1? Note that this
really is rather experimental; I presume jetty didn't come with this
version of commons-logging?



You're right, I have changed the commons-logging version to the latest one.
Now I have reverted to commons-logging-1.0.2

There are some cases which the weak-reference stuff cannot handle. And
even the weak-reference stuff works, commons logging cleans up but the
underlying logging library may not.



I suggest registering a ServletContextListener. Declare a <listener>
element in the web.xml file, with a nested <listener-class> element
containing the fully qualified classname of a logging-cleanup class. In
the contextDestroyed method of that class do this:
* LogFactory.release(
    Thread.currentThread().getContextClassLoader())
* somehow cleaning up the underlying logging library if needed.

If that doesn't help, let me know and we can look into it a bit
further.

From my code I call LogFactory.releaseAll() after removing the old web app context, and no luck :-(
Should my webapp use another copy of commons-logging.jar?

------------------------------------------------------------------------

Another issue:

I have noticed a strange class loading behaviour new to the latest commons-logging releases.

Here is the logging jars I use in my app:

jars used by the web server (Jetty):

   * commons-logging.jar and
   * log4j.jar

jars used by the webapp:

   *    logkit.jar

My web app uses Cocoon which uses Avalon LogKit, and makes me include logkit.jar, even though logging is redirected to log4j. Some other classes use directly commons-logging

With commons-logging-1.0.4 and 1.05 alpha1, I have to make logkit.jar available to Jetty, otherwise commons-loggings throws a ClassNotFoundException, because it cannot find

org/apache/log/Hierarchy.  I wonder why it tries to load LogKit if Log4j is 
already available?

F 18 12:08:54 <main> [fcc.ima.servidor2.ServidorIma] Error al iniciar servidor

java.lang.ExceptionInInitializerError
        at org.mortbay.util.Resource.newResource(Resource.java:73)
        at org.mortbay.util.Resource.newSystemResource(Resource.java:186)
        at 
org.mortbay.jetty.servlet.XMLConfiguration.configureDefaults(XMLConfiguration.java:151)
        at 
org.mortbay.jetty.servlet.WebApplicationContext.configureDefaults(WebApplicationContext.java:415)
        at 
org.mortbay.jetty.servlet.WebApplicationContext.doStart(WebApplicationContext.java:464)
        at org.mortbay.util.Container.start(Container.java:72)
        at org.mortbay.http.HttpServer.doStart(HttpServer.java:695)
        at org.mortbay.util.Container.start(Container.java:72)
        at fcc.ima.servidor2.ServidorIma.main(ServidorIma.java:50)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at 
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at 
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.mortbay.start.Main.invokeMain(Main.java:153)
        at org.mortbay.start.Main.start(Main.java:483)
        at org.mortbay.start.Main.main(Main.java:91)
        at fcc.ima.servidor.Inicializacion.main(Inicializacion.java:34)
Caused by: org.apache.commons.logging.LogConfigurationException: 
java.lang.NoClassDefFoundError: org/apache/log/Hierarchy (Caused by 
java.lang.NoClassDefFoundError: org/apache/log/Hierarchy)
        at 
org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:538)
        at 
org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:235)
        at 
org.apache.commons.logging.impl.LogFactoryImpl.getInstance(LogFactoryImpl.java:209)
        at org.apache.commons.logging.LogFactory.getLog(LogFactory.java:351)
        at org.mortbay.util.JarResource.<clinit>(JarResource.java:33)
        ... 17 more
Caused by: java.lang.NoClassDefFoundError: org/apache/log/Hierarchy
        at 
org.apache.commons.logging.impl.LogKitLogger.getLogger(LogKitLogger.java:77)
        at 
org.apache.commons.logging.impl.LogKitLogger.<init>(LogKitLogger.java:64)
        at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
        at 
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
        at 
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
        at 
org.apache.commons.logging.impl.LogFactoryImpl.newInstance(LogFactoryImpl.java:529)
        ... 21 more


On the other side, commons-logging-1.02 works ok.

Regards
   David

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