I have some 5 application running in my tomcat server. I want to build some kind of tool where I can be able to choose one application from the application list and than be able to view the following things-
1.)Detect low memory
2.)Enable or disable GC and class loading verbose tracing
3.)Detect deadlocks
4.)Control the log level of any loggers in an application
5.)Memory used by that application.
6.)Thread view for that application.
I want to have some kind of open source so that i can modify it and integrate it into my web project so that i can view it directly in a webpage.Is there something already existing.?
have a look at http://visualvm.java.net
Enable JMX for your Tomcat server: Monitoring and Managing Tomcat. Then you can manage it with any JMX console. JConsole is the one bundled in JDK.
Related
I am using IntelliJ 11 to run a spring mvc application in a Tomcat container as I developer. I have IntelliJ configured so that I can "update resources" to make my jsp changes live without needing a full restart of Tomcat. However, whenever I update the resources, my session in Tomcat is lost and I must re-login to my app.
Is there a way to get Tomcat to recognize my application resource changes while keeping my session alive?
While I reference IntelliJ in the question, it is really about Tomcat in general. A way to do this from IntelliJ would be great but any way to do this would be appreciated.
Tomcat is able to persist sessions across restart. The Standard Implementation uses a file called SESSIONS.ser. Obviously the objects stored is the session must be Serializable.
I have a Java EE 5 application which consists of three web projects. I'm using JBoss 5.1 web server and NetBeans 7.2 IDE.
I have the following problems:
I cannot start application in Debug mode. That I know of, there are two (best) approaches in NetBeans and Java: Remote debugging and debugging via shared memory. I read this post How to debug JBOSS application in netbeans? and I set debug parameters in Jboss configuration(I also know there are different parameter sets for shared memory and remote debugging), but when I go to attach debugger I got following errors:
If I use remote debugging I got error "Connection refused";
If I use shared memory I got error similar to this text "dt_shmem:file path could not be found".
These errors occur when I start JBoss by running run.bat file. If I start JBoss from Netbeans IDE, I can attach to remote process (still have problem with shared memory approach), but then I have other problems, regarding variable primitives and model binding in page life cycle (I will not write about that now).
How can I solve these problems so I can debug application? At least, how can I find a better error message when it fails. I could not find too much on the Net by looking for "Connection refused" error only.
Why I cannot just press run main project(or web project) and that netbeans start application, open it in new browser tab(as localhost) and start debug mode? I'm coming from .net background and VS is offering this as out of the box tool (called ASP .NET development server). Why I have to use external web server and with every change deploy new application and then attach to it? Why Netbeans cannot by default use JVM for running application, and later when I deploy application I will choose which web server to use!?
I hope someone will make this clear to me :)
Thanks
added Note at 03.01.2013.
Well, when I changed VM options in project.properties file of web project (added run.args.extra=-J-Xms256m -J-Xmx756m), I succeeded to debug application and heat breakpoint when executing the code. However, I still have strange problem with Managed Bean properties. I have select list on page, and it is connected to Boolean property. When nothing is selected it should be set to null value by default (and it is when I start JBoss server by running run.bat file), but its value is by default set to false! I checked parameters post values in firebug and there is no problem in posting parameters to bean. It looks to me that problem is when JSF framework is trying to map post values to Managed Beans properties, but I cannot find out why this is happening. I also checked faces-config.xml, but did not find any specific rule for mapping to this specific property. Any tips?
I'm reading up on JMX for the first time, and trying to see if its a feasible solution to a problem we're having on production.
We have an architecture that is constantly hitting a remote web service (managed by a different team on their own servers) and requesting data from it (we also cache from this service, but its a sticky problem where caching isn't extremely effective).
We'd like the ability to dynamically turn logging on/off at one specific point in the code, right before we hit the web service, where we can see the exact URLs/queries we're sending to the service. If we just blindly set a logging level and logged all web service requests, we'd have astronomically-large log files.
JMX seems to be the solution, where we control the logging in this section with a managed bean, and then can set that bean's state (setLoggingEnabled(boolean), etc.) remotely via some manager (probably just basic HTML adaptor).
My questions are all deployment-related:
If I write the MBean interface and impl, as well as the agent (which register MBeans and the HTML adaptor with the platform MBean server), do I compile, package & deploy those inside my main web application (WAR), or do they have to compile to their own, say, JAR and sit on the JVM beside my application?
We have a Dev, QA, Demo and Prod envrionment; is it possible to have 1 single HTML adaptor pointing to an MBean server which has different MBeans registered to it, 1 for each environment? It would be nice to have one URL to go to where you can manage beans in different environments
If the answer to my first question above is that the MBean interface, impl and agent all deploy inside your application, then is it possible to have your JMX-enabled application deployed on one server (say, Demo), but to monitor it from another server?
Thanks in advance!
How you package the MBeans is in great part a matter of portability. Will these specific services have any realistic usefulness outside the scope of this webapp ? If not, I would simply declare your webapp "JMX Manageable" and build it in. Otherwise, componentize the MBeans, put them in a jar, put the jar in the WEB-INF/lib and initialize them using a startup servlet configured in your web.xml.
For the single HTML adaptor, yes it is possible. Think of it as having Dev, QA, Demo and Prod MBeanServers, and then one Master MBeanServer. Your HTML Adaptor should render the master. Then you can use the OpenDMK cascading service to register cascades of Dev, QA, Demo and Prod in the Master. Now you will see all 5 MBeanServer's beans in the HTML adaptor display.
Does that answer your third question ?
JMX is a technology used for remote management of your application and for a situation for example when you want to change a configuration without a restart is the most proper use.
But in your case, I don't see why you would need JMX. For example if you use Log4j for your logging you could configure a file watchdog and just change logging to the lowest possible level. I.e. to debug. This does not require a restart and IMHO that should have been your initial design in the first place i.e. work arround loggers and levels. Right now, it is not clear what you mean and what happens with setLoggingEnable.
In any case, the managed bean is supposed to be deployed with your application and if you are using Spring you are in luck since it offers a really nice integration with JMX and you could deploy your spring beans as managed beans.
Finally when you connect to your process you will see the managed beans running for that JVM. So I am not sure what exactly you mean with point 2.
Anyway I hope this helps a little
I'm looking for a way to properly shutdown (Undeploy) an Java Web Application within the application itself. I've tried System.exit(), but this not only shutdown the webApp but also messes up Glassfish.
I know about the contextlistener, I'm just wondering how to start the shutdown procedure.
Deploying of web applications is the responsibility of application server. I do know how is it in Glassfish but other app. servers (e.g. JBoss, Tomcat etc) have web based management application that allow to do this.
If you want to undeploy application programmatically from the application itself you can use JMX. Refer to the glassfish JMX implementation to know which bean to call. But IMHO I do not think that you really need this.
The usual approach is to use the asadmin undeploy command.
The general form for the command is:
as-install/bin/asadmin undeploy war-name
For war-name, use the literal hello, not the full hello.war name.
For the hello.war example, the command is:
as-install/bin/asadmin undeploy hello
See the following references:
http://docs.oracle.com/cd/E19798-01/821-1757/geyvr/index.html
http://docs.oracle.com/docs/cd/E19798-01/821-1758/undeploy-1/index.html
To undeploy programmatically, you can use JSR-88 though i cant really see a reason as to why you would want to do this. See
http://blogs.oracle.com/japod/entry/using_jsr_88_for_web
http://www.jcp.org/en/jsr/detail?id=88
How to activate JMX on my JROCKIT JVM for access with jconsole?
(somewhat a follow up question to How to activate JMX on my JVM for access with jconsole?)
The main reason I ask is, because I get strange errors if I try to run jboss (6.0.0.Final) with activated JMX, and jboss doesn't start correctly. So maybe it is a jboss problem.
The easiest way to do this, and at the same time support a variety of potential networking configuration challenges, as well as work with any JVM (most ?) is to install a JMXConnectorServer in the JBoss App Server. Now you're using standard J2SE connectivity.
Older builds of JBoss 6 had this support built in and I'm not sure why jboss removed it but here's how you can recreate it.
Find the jar jboss-as-jbossas-jmx-remoting.jar which has a maven signature of org.jboss.jbossas / jboss-as-jbossas-jmx-remoting. Copy it to the [jboss-home]/server/[your-server]/lib directory.
Create a file like jmx-connector-service.xml as outlined below and drop it into your [jboss-home]/server/[your-server]/deploy directory.
(Sorry, was having trouble formatting XML for stackoverflow).
When the server starts, you will see a log statement like this, pretty early on:
INFO [JMXConnectorServerService] JMX Connector server: service:jmx:rmi://10.213.14.95/jndi/rmi://10.213.14.95:1090/jmxconnector
You can tweak the bindings, the use of a registry, the ports etc, but now you can open JConsole and connect to service:jmx:rmi://10.213.14.95/jndi/rmi://10.213.14.95:1090/jmxconnector.
You can find more information on the service here.