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Posted to users@tomcat.apache.org by Emmanuel Soden <e....@gmail.com> on 2008/11/04 19:36:20 UTC
Re: [JMX] org.apache.catalina.session.StandardManager not serializable
Hi,
Using Tomcat 5.5.27 with JDK 1.5.0_11, I'm trying to retrieve the attribute
"manager" from the MBean
"Catalina:J2EEApplication=none,J2EEServer=none,j2eeType=WebModule,name=//localhost/".
But I'm getting thre following error.
Exception in thread "main" java.rmi.UnmarshalException: error unmarshalling
return; nested exception is:
java.io.WriteAbortedException: writing aborted;
java.io.NotSerializableException:
org.apache.catalina.session.StandardManager
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:157)
at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
at javax.management.remote.rmi.RMIConnectionImpl_Stub.getAttribute(Unknown
Source)
at
javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.getAttribute(RMIConnector.java:857)
at test.jmx.JmxTest.main(JmxTest.java:37)
Caused by: java.io.WriteAbortedException: writing aborted;
java.io.NotSerializableException:
org.apache.catalina.session.StandardManager
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1309)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:348)
at sun.rmi.server.UnicastRef.unmarshalValue(UnicastRef.java:290)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:139)
... 4 more
Caused by: java.io.NotSerializableException:
org.apache.catalina.session.StandardManager
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1081)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:302)
at sun.rmi.server.UnicastRef.marshalValue(UnicastRef.java:258)
at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:304)
at sun.rmi.transport.Transport$1.run(Transport.java:153)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java: 149)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:466)
at
sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:707)
at java.lang.Thread.run(Thread.java:595)
I attach to this mail a sample that able to reproduce this. In fact I would
like to know how to retrieve this Class, I hope that this class implement
Serializable otherwise I don't know why StandardManager is exposed as Jmx
Attribute.
Additionnaly, when I try to retrieve an attribute like "managedResource"
from the MBean "Catalina:host=localhost,type=Host". I got the following
execption
Exception in thread "main" java.rmi.UnmarshalException: error unmarshalling
return; nested exception is:
java.io.WriteAbortedException: writing aborted;
java.io.NotSerializableException: org.apache.catalina.util.LifecycleSupport
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:157)
at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
at javax.management.remote.rmi.RMIConnectionImpl_Stub.getAttribute(Unknown
Source)
at
javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.getAttribute(RMIConnector.java:857)
at test.jmx.JmxTest.main(JmxTest.java:36)
see attached file for complete stacktrace.
Regards,
Emmanuel
Re: [JMX] org.apache.catalina.session.StandardManager not serializable
Posted by Emmanuel Soden <e....@gmail.com>.
Thank you Chuck,
What I understand know is that, you can only retrieve primitive values.
In the same way, I was trying to retrieve a "org.apache.catalina.Context"
from the MBean
"Catalina:J2EEApplication=none,J2EEServer=none,j2eeType=WebModule,name=//localhost/"
using the JMX operation operation "findMappingObject" and I get the
following error
Caused by: java.rmi.UnmarshalException: error unmarshalling return; nested
exception is:
java.io.WriteAbortedException: writing aborted;
java.io.NotSerializableException: org.apache.catalina.util.LifecycleSupport
at sun.rmi.server.UnicastRef.invoke(Unknown Source)
at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
at javax.management.remote.rmi.RMIConnectionImpl_Stub.invoke(Unknown Source)
at
javax.management.remote.rmi.RMIConnector$RemoteMBeanServerConnection.invoke(Unknown
Source)
My suggestion:
- If you want to expose a JMX object all of their attributes or operations
have to be serializable.
- Provide a different set of interface for Remote JMX connection and local
JMX connection.
- Add to the documentation a list of objects that can be retrieved
Regards,
Emmanuel
On 11/4/08, Caldarale, Charles R <Ch...@unisys.com> wrote:
>
> > From: Emmanuel Soden [mailto:e.soden@gmail.com]
> > Subject: Re: [JMX] org.apache.catalina.session.StandardManager not
> serializable
> >
> > Using Tomcat 5.5.27 with JDK 1.5.0_11, I'm trying to retrieve
> > the attribute "manager" from the MBean
> > "Catalina:J2EEApplication=none,J2EEServer=none,
> > j2eeType=WebModule,name=//localhost/".
>
> I don't think there's any requirement for any app to guarantee that
> attributes are serializable, and I suspect trying to make StandardManager so
> would create a host of issues inside Tomcat.
>
> Perhaps you should try retrieving the attributes you're interested in from
> this JMX location instead:
> "Catalina:type=Manager,path=/,host=localhost"
> Its attributes are all retrievable, at least according to JConsole.
>
> > when I try to retrieve an attribute like "managedResource"
> > from the MBean "Catalina:host=localhost,type=Host"
>
> From a brief perusal of the 6.0 code (sorry, not the level you're using),
> there appears to be extremely limited use of the "managedResource"
> attribute, despite its presence in most of the MBeans. Looks like in the
> vast majority of cases, the attribute is never set.
>
> - Chuck
>
>
> THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY
> MATERIAL and is thus for use only by the intended recipient. If you received
> this in error, please contact the sender and delete the e-mail and its
> attachments from all computers.
>
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>
>
Re: [JMX] org.apache.catalina.session.StandardManager not serializable
Posted by Jess Holle <je...@ptc.com>.
Caldarale, Charles R wrote:
>> From: Emmanuel Soden [mailto:e.soden@gmail.com]
>> Subject: Re: [JMX] org.apache.catalina.session.StandardManager not serializable
>>
>> Using Tomcat 5.5.27 with JDK 1.5.0_11, I'm trying to retrieve
>> the attribute "manager" from the MBean
>> "Catalina:J2EEApplication=none,J2EEServer=none,
>> j2eeType=WebModule,name=//localhost/".
>>
> I don't think there's any requirement for any app to guarantee that attributes are serializable, and I suspect trying to make StandardManager so would create a host of issues inside Tomcat.
>
> Perhaps you should try retrieving the attributes you're interested in from this JMX location instead:
> "Catalina:type=Manager,path=/,host=localhost"
> Its attributes are all retrievable, at least according to JConsole
>> when I try to retrieve an attribute like "managedResource"
>> from the MBean "Catalina:host=localhost,type=Host"
>>
>
> >From a brief perusal of the 6.0 code (sorry, not the level you're using), there appears to be extremely limited use of the "managedResource" attribute, despite its presence in most of the MBeans. Looks like in the vast majority of cases, the attribute is never set.
>
More generally I have had cases where I've had an attribute exposed via
JMX for /in-process /usage that then blows chunks with out-of-process
usage. This should be avoided, but where it cannot be it should be
documented as "the way things are" and possibly addressed by
replaceObject(). [In my recent case I used replaceObject() to replace
my non-serializable data with an approximation thereof whose toString()
would show something somewhat meaningful in a remote JMX console.]
--
Jess Holle
RE: [JMX] org.apache.catalina.session.StandardManager not
serializable
Posted by "Caldarale, Charles R" <Ch...@unisys.com>.
> From: Emmanuel Soden [mailto:e.soden@gmail.com]
> Subject: Re: [JMX] org.apache.catalina.session.StandardManager not serializable
>
> Using Tomcat 5.5.27 with JDK 1.5.0_11, I'm trying to retrieve
> the attribute "manager" from the MBean
> "Catalina:J2EEApplication=none,J2EEServer=none,
> j2eeType=WebModule,name=//localhost/".
I don't think there's any requirement for any app to guarantee that attributes are serializable, and I suspect trying to make StandardManager so would create a host of issues inside Tomcat.
Perhaps you should try retrieving the attributes you're interested in from this JMX location instead:
"Catalina:type=Manager,path=/,host=localhost"
Its attributes are all retrievable, at least according to JConsole.
> when I try to retrieve an attribute like "managedResource"
> from the MBean "Catalina:host=localhost,type=Host"
>From a brief perusal of the 6.0 code (sorry, not the level you're using), there appears to be extremely limited use of the "managedResource" attribute, despite its presence in most of the MBeans. Looks like in the vast majority of cases, the attribute is never set.
- Chuck
THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers.
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