Is that possible to find all open ports on my machine that were registered with JNDI ?
It would be good to find out some util from Ubuntu but Java code also will be OK.
UPDATE: After JSP's clarification I have revised my question.
I would do the following:
A. Parse your application server configuration - for example, for standalone configuration of Jboss AS 7.x , you should parse the standalone/configuration/standalone.xml
B. Read the JNDI configuration from the XML, and understand what ports should be used.
C. Use
System.getRuntime().exec
In order to invoke netstat -na , filter out those ports who exist in the list obtained from A, and that are in ESTABLISHED state.
Some issues wiht my solution:
A. As far as I know, According to Java EE spec, you should not execute process from a Java enterprise application.
To overcome this, you can have some j2se application running as service, communication with the application server.
B. I assumed that the server and the code that needs to know about the JNDI ports exist on the same machine.
If the code that needs to know the ports should be run on a different machine, you should expose this information to the client (i.e - via web UI, REST, etc...)
Related
Is it possible to deploy different versions of single application on one IBM Websphere Application Server (WAS)?
For example I have:
App1 with url binding http://app/1.0/service/
App2 with url binding http://app/2.0/service/
Is it possible?
I think not due to port listening issue, but maybe there is some chance...
It should be possible, but with some restrictions (depending on your application). If you have WAS ND 8.5.5, then you have Application Edition management feature. Read more details on that page.
If you are on the older version, you will have to change several things during deployment, e.g.:
context-root of the application
JNDI EJB binding names
if other version is using different database - update the JDBC references
if other version is using additional resources (like queues, qcf) update them also.
Actually, port listening has nothing to do with it, as both application will use same port, but different context-roots.
This of course assumes that application doesn't have hard coded values in it (like context root, jndi names, etc).
Jolokia is uncharted territory for me, and after having read the documentation, I'm still not sure if it'll work with the scenario I have in mind.
Setup:
Tomcat application server (version ranges from 6.x to 7.x), usually on a Windows platform, occasionally a flavour of Linux.
Deployed third-party Java web application (SAP BusinessObjects) with JMX monitoring enabled (accessible through RMI).
Possible gotcha's:
The Java web application to be monitored is commercial and closed source, so modifications are not possible. The only thing that can be changed is the JMX port number
The JMX endpoint is a custom one, thus not the default jmxrmi endpoint.
The JMX connection requires authentication.
Goal:
What I'd like to do is to deploy the Jolokia WAR file onto the Tomcat server and then configure it so that I can read the MBean attributes from the other web application.
I would code the client myself using Python (version 3) and the Requests HTTP library.
I've been reading through the Jolokia documentation (again, I'm a complete newbie at this point), but can't figure out if this would be possible or not (as I can't seem to find where to enter the JMX/RMI url or the authentication information).
Questions:
Can I use the WAR agent for this setup?
If not, can you please explain why (so I can understand, not because I don't believe you). Also, is there another agent that's more suited for this scenario?
If yes, can you point me in the right direction how to configure the Jolokia to the web application to connect to?
First of all, Jolokia by passes the JSR-160 connector stuff completely, so there is no need for any JMX/RMI authentication. The whole purpose of Jolokia is to provide a bridge over HTTP/JSON to the internal JMX subsystem. Depending on the agent, you can secure Jolokia quite easily. For the WAR agent, securing is the same as for any Java EE web app: Setup some roles and users for tomcat (e.g. in tomcat-users.xml) and reference the role in the security contstraints within the jolokia.war's /WEB-INF/web.xml.
To your questions:
Yes, you can. If you don't have any specific authentication needs, simply drop the jolokia.war into tomcat's /webapps directory. I suggest to try this first before adding security. For deinstalling the agent, simply remove the war.
As an alternative, you could also use the JVM agent, which opens an own HTTP server on an extra port (default: 8778). More on this in the reference manual
There is no need for a dedicated connection to the web app since MBeans are registered globally and are accesible from anywhere in the JVM. A webapp should of course select carefully the management information it exposes. So, there is no extra step needed and you can access the MBeans for the WEB app directly (except when it does something unusual with Java security, but I don't think so).
To test the installation, simply connect to the Tomcat with your browser and the context /jolokia (e.g. "http://localhost:8080/jolokia"). You should see the version information about the agent itself.
The next step would be to explore the JMX namespace, either with the browser (and operation "list" like in http://localhost:8080/jolokia/list , but that's tedious) or with a client like j4psh or hawt.io. Hopefully you will find the MBeans of your webapp you are looking for.
I'm currently having 2 Weblogic admin servers in 2 different domains created on the same machine.
I want to convert one of the admin server to a managed server and then use them together to deploy a Java application. Is this feasible? If yes, how?
I'm currently using Weblogic Server 10.3.
PS: I'm quite new to Weblogic domain creation and administration. Please revert for any more details needed.
The simple answer is no, however, adding a managed server to a domain is extremely simple. See the documentation here. When deploying your application you'll need to target both servers or create a cluster (also very easy), add both machines to it and give the cluster name as the target.
Note, it is generally not concidered best practice to target applications to the Admin server (although it's fine when you're developing on your local machine). If you have the resources available on your environment, you could create two managed servers and put them in a cluster. Depending on the configuration of your Admin server, you may be able to reduce it's size if memory is tight.
The situation: one server machine with some installed Application Servers (JBoss). JVM is alone for the whole machine and it's used by every server.
Every server has his own RMI stub which is registered in RMI registry while server is starting. But, for correct work of RMI it's needed to define Java property java.rmi.server.codebase = path to jar file with classes for stubing. This is the main problem: when many servers use one JVM, but defined path is to only one application server directory. Thus, RMI clients can't connect to different servers and invoke different versions of remote interfaces.
My view is there're the following ways:
Create separate RMI registry in every application server (in JBoss), but I don't know how it makes?
Add into the name of stub sign of application server (e.g. host:port) and then from client lookup jndi name of needed server+stub?
Are there any other variants? Maybe someone already met with such problem?
(1) is your only choice. It is done with LocateRegistry.createRegistry(), unless JBoss has a way to configure it permanently. You will have to use separate ports per Registry.
(2) doesn't even make sense to me without further explanation, unless it is really a continuation of (1).
I am currently developing an application for some researchers in my university.It's a small java program that you can use by command line. The next step is to package that program and deploy it to an application server. Some clients program will submit requests to the server who will call the tool that I wrote. Lately, we will add more tools to the server and he has to dispatch the requests to the right tool.
Which application server fits my needs ? I have looked for Tomcat, Jetty and Glassfish but it seems that they are only used for web application.
Is it possible to use those servers in some context different from web context? Which package archive should i use (jar, war) ?
Any advice?
Some clients program will submit requests to the server who will call the tool that I wrote.
The big question is what server-side technology and what communication protocol can you use between the clients and the server. You basically have two major options: HTTP and web services (in that case, consider using either JAX-WS or JAX-RS) or RMI-IIOP and EJBs (in that case, you'll have to use a Java EE compliant server like GlassFish).
I have looked for Tomcat, Jetty and Glassfish but it seems that they are only used for web application.
Not really. As I said, they can also be used for web services oriented applications. And GlassFish can be used for EJBs applications.
Which package archive should i use (jar, war)
The packaging will depend on the type of application you'll write, it's not something that you choose upfront, it's just a consequence. EJBs are packaged in an EJB JAR and typically deployed inside an EAR; Servlet based web services are deployed inside a WAR.
You really need to think about what technology to use first (with the current level of detail, I can't provide more guidance).
Do you even need an application server? There's nothing stopping you from adding the necessary network bindings and deploying it on its own.
Of the servers you mention, you've got 2 different categories: servlet containers and full-stack Java EE servers
Tomcat and Jetty are servlet containers. That doesn't mean that you can only do web stuff with them and you could manually add the required libraries to get a full Java EE server.
Glassfish is a full-stack Java EE server and can be compared with JBoss (both are open source) or the commercial rivals Weblogic and Websphere.
Sometimes this question is simple as the environment you are working in mandates a particular flavour of app server. You should check this first.
If you're not forced to use an app server, I'd ask why you think you need to use an app server?
I don't see why you would want to use tomcat, glassfish or jetty for a command line program.
If it's command-line based, and you want it to run server-side, you could write a little program that allows users to, for instance, telnet to your server, which in turn starts the CLI-application in question, and relays input / output to the client.
You may also want to look into Java Webstart, which makes deployment of new versions a breeze.
Actually we can't answer with so few elements.
- What are you planning to do
- With what technologies
- Where are you planning to host your application (have you got budget?)
- In which language are written the clients (even the future ones)?
- Could clients be on mobile phones (add some technlogy constraints...)
....
It would also be great to know what kind of request the clients will do, and what kind of response the server will provide...
Actually with what you tell us, all those application servers can do what you want...
I have looked for Tomcat, Jetty and
Glassfish but it seems that they are
only used for web application
You could even make a webapplication (servlet) and on the clientside use a httpclient to call that servlet... there are so many options :)
vive Paris!