August 2006 - jboss-dev-forums - Jboss List Archives

[Design of JBoss Profiler] - Re: Class Leakage Tool

by clebert.suconic＠jboss.com

"ngolovin" wrote : | What you are suggesting is exactly what I did. I saw the matrix and the duplicates. Then I clicked on loader references and saw there approx. 2000 references (I have removed the 200-reference limit in my copy of the references.jsp) | What I do is... I - I always look for the classLoader reference. It's hard to create a filter for this. I couldn't come up with a logic, as sometimes a third level is what's causing a leakage. For example if you keep a reflection reference, you will have: reflectionObject->class->ClassLoader And this is really hard. If you have a classLoader loading 2000 classes, and only one class is kept referenced, all the 2000 classes will still be in the memory because of the ArrayList on ClassLoader. (read source code from JDK you will know what I'm talking about). Try looking at field references first. Than move to another level. Also.. when you said about parent classLoaders, I didn't understand what you meant. But what usually happens is a class or an instance of that class, loaded by any different classLoader keeping directly or indirectly a reference to your classLoader. an example is Commons Logging. (if you're not using our patched version) CommonsLogging will keep a HashMap of Loggers using Class as the key. Class has the reference to the classLoader and CommonsLogging is loaded from System ClassLoader. I don't know if this helps... But... as I said before.. .chasing a redeployment leakage is never fun, even if you were using the most expensive tool. Clebert Suconic View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967515#3967515 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967515

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[Design of JBoss Profiler] - Re: Class Leakage Tool

by clebert.suconic＠jboss.com

So, you will have to drill down your references until you find the root cause. Please, if you find anything related to JBoss, we would like to know. (open a thread on the proper forum. For example if you found something on EJB, open a thread on EJB forum). Notice that we are aware of EJB3 leaking redeployments at this point. (There is a JIRA opened) View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967513#3967513 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967513

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[Design of JBoss Profiler] - Re: Class Leakage Tool

by ngolovin

Hi Clebert, either I have expressed myself way too vaguely, or you answer was for another thread. What you are suggesting is exactly what I did. I saw the matrix and the duplicates. Then I clicked on loader references and saw there approx. 2000 references (I have removed the 200-reference limit in my copy of the references.jsp) My problem is, I am looking for the reference, which prevents the my ClassLoader from being collected by the GC. Do you have any suggestions on how to find this reference? As far as I understand, this reference will not be coming from the classes, which were loaded by that ClassLoader, but should come from classes loaded by parent classloaders. Is it possible to put a filter on references to show only references from classes, loaded by parent classloaders? If you have an ideea how to implement it in Java, I could implement it myself. I don't even have a clue, how to find out which classloader loaded a particular class. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967510#3967510 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967510

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[Design of JBoss Profiler] - Re: Class Leakage Tool

by clebert.suconic＠jboss.com

On JBossProfiler.war there is a WebInterface that will automate the navigation on JVMTIInterface. Go to http://localhost:8080/jboss-profiler Look at the third option on the Menu. That will intercept class references in a Tomcat/JBoss instance. You will need JVMTIInterface (the MBean) deployed as well. You can redeploy your application couple times, forcing classes being loaded twice, and look for duplications. You can play with Clean Session and get duplications again every time you execute a redeployment. The application will "download" a matrix from C++layer into Java Layer. If you redeploy the matrix will be out dated. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967506#3967506 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967506

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[Design of JBoss ESB] - Re: Registry Design

by mugdho

So Tom, our current objective is to think along the lines of the QueryManager right? Like you said on the lines of the data model, wouldn't the RegistryObject be a part of the Registry which the user would be plugging in? So we would need to think as to how the implementation of the QueryManager communicates with the RegistryObject and its specializations right? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967501#3967501 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967501

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[Design of JBoss ESB] - Re: Registry Design

by tfennelly

Sorry - a missleading typo there in the last post. I should have said "Numerous specialisations of RegistryObject that I think are relavant..." View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967496#3967496 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967496

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[Design of JBoss Profiler] - Re: Class Leakage Tool

by ngolovin

Hello Clebert, thank you for the great tool. I have a question -- the number of references is overwhelming, even with the display limit of 200, so it's hard to find this very bad reference which prevents classloader to be gc-ed. Most of the references to the classloader however comes from its own classes(i.e. loaded by this classloader and its children), and should not be the problem. Is it possible to somehow filter references from the own classes and find that bad references from the container? Or am I generally misunderstanding something? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967495#3967495 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967495

18 years, 1 month

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[Design of Security on JBoss] - Re: Negotiate with Kerberos

by anil.saldhana＠jboss.com

JSR-196 has support for challenge-response handshake. There is a public draft feedback phase going on now. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967494#3967494 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967494

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[Design of JBoss ESB] - Re: Registry Design

by tfennelly

Hey Mughdo, sorry for being so slow in replying. I had some serious laptop issues - all sorted now though!! I spent some time this morning looking at these reg specs - JAXR, UDDI etc. What's outlined in the JAXR spec def seems to be more inline with the direction that Mark wants us to take (as I understand it ;-) ). I'm talking mainly about the data model!! See the UMLs for an idea of the type of relationships. In the JAXR model, it has the concept of: - A RegistryObject which acts as a base type for everything that's stored in the registry. - Numerous specialisations of ServiceObject that I think are relavant to anything we'd be doing wrt a regsitry interface. These include: Service, ServiceBinding, Classification (and related types!) and more... In order to access these RegistryObjects JAXR defines the QueryManager interface. We'll need something along the lines of this interface too. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967493#3967493 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967493

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[Deployers on JBoss (Deployers/JBoss)] - Re: Ordering of .ear subdeployments

by bstansberry＠jboss.com

Please don't interpret the following as a vote (at least not in the Apache sense of "intent to veto"). My -1 before was for changing the test w/o hashing through the issues; you've now hashed through the issues :) I do think having apps that work in 4.0.4 no longer work in 4.0.5 is not too good, particularly since we've been teaching the implicit ordering rules in training classes for a long time. I don't have anywhere near the same level of concern about an app working in 4.0.4 not working without tweaking in 5.0.0, so one option is to change the default to strict for 5.0.0 and leave it at implicit for 4.x. If you guys go with strict for 4.0.5, I certainly don't mind having the testbeancluster.jar changed to conform. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3967491#3967491 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3967491

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jboss-dev-forums August 2006