ClassCastException

blinder

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Feb 16, 2011, 12:40:11 PM2/16/11

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Hello, I just went through the setup and configuration (http://
code.google.com/p/memcached-session-manager/wiki/
SetupAndConfiguration)
and each time i try to start tomcat (Apache Tomcat/6.0.20 on mac
10.5.8) i get the following stack trace:

Caused by: java.lang.ClassCastException: class
de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory
at java.lang.Class.asSubclass(Class.java:3018)
at
de.javakaffee.web.msm.MemcachedBackupSessionManager.loadTranscoderFactoryClass(MemcachedBackupSessionManager.java:
397)
at
de.javakaffee.web.msm.MemcachedBackupSessionManager.createTranscoderFactory(MemcachedBackupSessionManager.java:
382)
at
de.javakaffee.web.msm.MemcachedBackupSessionManager.getTranscoderFactory(MemcachedBackupSessionManager.java:
348)

I've tried other transcoder factory implementations (the built-in java
serializer, and javolution's) all result in the same class cast
exception.

Using memcached-session-manager-1.3.6.jar which is in CATALINE_HOME/
lib

My context looks like:

<Context path="/app-name">
<Manager
className="de.javakaffee.web.msm.MemcachedBackupSessionManager"
memcachedNodes="n1:localhost:11211"
requestUriIgnorePattern=".*\.(png|gif|jpg|css|js)$"

transcoderFactoryClass="de.javakaffee.web.msm.JavaSerializationTranscoderFactory"
/>
</Context>

i'm guessing i've missed something obvious but i'm just at a loss
right now. any help/guidance would be appreciated.

Martin Grotzke

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Feb 16, 2011, 12:44:44 PM2/16/11

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Can you try to remove the transcoderFactoryClass attribute?

Cheers,
Martin

Martin Grotzke

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Feb 16, 2011, 1:09:50 PM2/16/11

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The exception and posted configuration don't fit together. Can you check again and/or provide the complete log output?

Cheers,
Martin

Am 16.02.2011 18:41 schrieb "blinder" <blinde...@gmail.com>:

blinder

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Feb 16, 2011, 12:56:52 PM2/16/11

to memcached-session-manager

Hi Martin,
yes, just tried that and i got this again:
Caused by: java.lang.ClassCastException: class
de.javakaffee.web.msm.JavaSerializationTranscoderFactory

my context now looks like:

<Context path="/app-name">
<Manager
className="de.javakaffee.web.msm.MemcachedBackupSessionManager"
memcachedNodes="n1:localhost:11211"
requestUriIgnorePattern=".*\.(png|gif|jpg|css|js)$"

/>
</Context>

On Feb 16, 12:44 pm, Martin Grotzke <martin.grot...@googlemail.com>
wrote:

martin.grotzke

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Feb 16, 2011, 3:12:25 PM2/16/11

to memcached-session-manager

Please can you provide the complete log output?

You can also check out this sample and modify it so that I can
reproduce your issue:
https://github.com/magro/msm-sample-webapp/tree/simpleservlet

Cheers,
Martin

blinder

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Feb 16, 2011, 4:37:54 PM2/16/11

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ok, so i got past the ClassCastException. turns out it was all my
fault. i had downloaded the wrong version of msm (i had originally
1.4.0RC3). Changing that to the featured (1.3.6) fixed the
ClassCastException.

Now, however, it seems there's something odd with finding classes for
kryo. I'm currently getting:

Caused by: java.lang.ClassNotFoundException:
com.esotericsoftware.reflectasm.FieldAccess

my classpath (have tried both WEB-INF/lib and CATALINA_HOME/lib)
contains all required jar files including: reflectasm-0.9.jar (which
does indeed have FieldAccess)

strange.

On Feb 16, 3:12 pm, "martin.grotzke" <martin.grot...@googlemail.com>
wrote:

Martin Grotzke

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Feb 16, 2011, 5:05:25 PM2/16/11

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On Wed, Feb 16, 2011 at 10:37 PM, blinder <blinde...@gmail.com> wrote:
> ok, so i got past the ClassCastException. turns out it was all my
> fault. i had downloaded the wrong version of msm (i had originally
> 1.4.0RC3). Changing that to the featured (1.3.6) fixed the
> ClassCastException.

Strange, also with 1.4.0RC3 you shouldn't get the ClassCastException.
Can you check
https://github.com/magro/msm-sample-webapp/tree/simpleservlet
and tried to reproduce the issue with this setup?

>
> Now, however, it seems there's something odd with finding classes for
> kryo. I'm currently getting:
>
> Caused by: java.lang.ClassNotFoundException:
> com.esotericsoftware.reflectasm.FieldAccess
>
> my classpath (have tried both WEB-INF/lib and CATALINA_HOME/lib)
> contains all required jar files including: reflectasm-0.9.jar (which
> does indeed have FieldAccess)
>
> strange.

msm-kryo-serializer, kryo, reflectasm, asm etc. all have to be in
WEB-INF/lib and _must not_ exist in CATALINA_HOME/lib.

If this is the case for you probably the best is to change the
msm-sample-webapp until it also produces the issue you describe.

Cheers,
Martin

blinder

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Feb 17, 2011, 2:48:04 PM2/17/11

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On Feb 16, 5:05 pm, Martin Grotzke <martin.grot...@googlemail.com>
wrote:

> Strange, also with 1.4.0RC3 you shouldn't get the ClassCastException.
> Can you check
> https://github.com/magro/msm-sample-webapp/tree/simpleservlet
> and tried to reproduce the issue with this setup?

I will give this is a shot, after i get this to work. heh, just
changing the version did seem to fix the casting exception. but yeah
i'll dig a little deeper into that one when time permits.

>
> msm-kryo-serializer, kryo, reflectasm, asm etc. all have to be in
> WEB-INF/lib and _must not_ exist in CATALINA_HOME/lib.

yes, this is absolutely the case. currently in my WEB-INF/lib i have:
asm-3.2.jar
kryo-1.-3.jar
kryo-serializers-0.8.jar
minlog-1.2.jar
msm-kryo-serializer-1.3.6.jar
reflectasm-0.9.jar

in CATALINA_HOME/lib i have:
memcached-session-manager-1.3.6.jar
memcached-2.5.jar

>
> If this is the case for you probably the best is to change the
> msm-sample-webapp until it also produces the issue you describe.

okay, hmmm, i'll give this a shot.

mil...@gmail.com

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May 25, 2011, 7:40:00 AM5/25/11

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I got this ex. again under v.1.4.1,any advice? If I left the transcoderFactoryClass not configured(default value),it works fine

/tomcat/lib

memcached-2.5.jar

memcached-session-manager-1.4.1.jar

/tomcat/webapp/app/WEB-INF/lib

msm-kryo-serializer-1.4.1.jar

reflectasm-0.9.jar

kryo-1.03.jar

minlog-1.2.jar

asm-3.2.jar

kryo-serializers-0.8.jar

<Manager className="de.javakaffee.web.msm.MemcachedBackupSessionManager"

memcachedNodes="n1:localhost:11211"

sessionBackupAsync="false"

requestUriIgnorePattern=".*\.(ico|png|gif|jpg|css|js)$"

transcoderFactoryClass="de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory"

customConverter="de.javakaffee.web.msm.serializer.kryo.CGLibProxySerializerFactory,de.javakaffee.web.msm.serializer.kryo.HibernateCollectionsSerializerFactory"

/>

INFO: MemcachedBackupSessionManager starts initialization... (configured nodes definition n1:localhost:11211, failover nodes null)

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.SessionTrackerValve <init>

INFO: Setting ignorePattern to .*\.(ico|png|gif|jpg|css|js)$

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.SessionTrackerValve getSessionCookieName

FINE: Using session cookie name from context: JSESSIONID

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.MemcachedBackupSessionManager setLockingMode

INFO: Setting lockingMode to null

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.MemcachedBackupSessionManager createTranscoderFactory

INFO: Creating transcoder factory de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.MemcachedBackupSessionManager loadTranscoderFactoryClass

FINE: Loading transcoder factory class de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory using classloader WebappClassLoader

context: /manager

delegate: false

repositories:

----------> Parent Classloader:

org.apache.catalina.loader.StandardClassLoader@10c832d2

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.MemcachedBackupSessionManager loadTranscoderFactoryClass

INFO: Could not load transcoderfactory class with classloader WebappClassLoader

context: /manager

delegate: false

repositories:

----------> Parent Classloader:

org.apache.catalina.loader.StandardClassLoader@10c832d2

, trying org.apache.catalina.loader.StandardClassLoader@10c832d2

May 25, 2011 7:19:49 PM org.apache.catalina.core.StandardContext start

SEVERE: Error manager.start()

java.lang.RuntimeException: Could not create transcoder factory.

at de.javakaffee.web.msm.MemcachedBackupSessionManager.getTranscoderFactory(MemcachedBackupSessionManager.java:350)

at de.javakaffee.web.msm.MemcachedBackupSessionManager.createTranscoderService(MemcachedBackupSessionManager.java:342)

at de.javakaffee.web.msm.MemcachedBackupSessionManager.startInternal(MemcachedBackupSessionManager.java:307)

at de.javakaffee.web.msm.MemcachedBackupSessionManager.start(MemcachedBackupSessionManager.java:1454)

at org.apache.catalina.core.StandardContext.start(StandardContext.java:4713)

at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)

at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)

at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)

at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1079)

at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:1002)

at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:506)

at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1315)

at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)

at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)

at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1061)

at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)

at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)

at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)

at org.apache.catalina.core.StandardService.start(StandardService.java:525)

at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)

at org.apache.catalina.startup.Catalina.start(Catalina.java:595)

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:597)

at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)

at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)

Caused by: java.lang.ClassNotFoundException: de.javakaffee.web.msm.serializer.kryo.KryoTranscoderFactory

at java.net.URLClassLoader$1.run(URLClassLoader.java:200)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:188)

at java.lang.ClassLoader.loadClass(ClassLoader.java:307)

at java.lang.ClassLoader.loadClass(ClassLoader.java:252)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:247)

at de.javakaffee.web.msm.MemcachedBackupSessionManager.loadTranscoderFactoryClass(MemcachedBackupSessionManager.java:400)

at de.javakaffee.web.msm.MemcachedBackupSessionManager.createTranscoderFactory(MemcachedBackupSessionManager.java:382)

at de.javakaffee.web.msm.MemcachedBackupSessionManager.getTranscoderFactory(MemcachedBackupSessionManager.java:348)

... 26 more

May 25, 2011 7:19:49 PM org.apache.catalina.core.StandardContext start

SEVERE: Context [/manager] startup failed due to previous errors

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.MemcachedBackupSessionManager stop

INFO: Removing sessions from local session map.

May 25, 2011 7:19:49 PM de.javakaffee.web.msm.MemcachedBackupSessionManager stop

INFO: Stopping services.

May 25, 2011 7:19:49 PM org.apache.catalina.core.StandardContext start

SEVERE: Exception during cleanup after start failed

java.lang.NullPointerException

at de.javakaffee.web.msm.MemcachedBackupSessionManager.stop(MemcachedBackupSessionManager.java:1487)

at org.apache.catalina.core.StandardContext.stop(StandardContext.java:4875)

at org.apache.catalina.core.StandardContext.start(StandardContext.java:4749)