What is JBOSS?
JBoss is a popular open source application server based on JEE technology. Being JEE based, the JBoss supports cross-platform java applications. It was embedded with Apache Tomcat web server. It runs under any JVM of 1.3 or later versions. JBoss supports JNDI, Servlet/JSP (Tomcat or Jetty), EJB, JTS/JTA, JCA, JMS, Clustering (Java Groups), Web Services (Axis), and IIOP integration (JacORB).
What is JBoss cache in short?
JBoss cache is a product. Frequently accessed Java objects are cached by utilzing JBoss cache to improve the performance of e-business applications. JBoss decreases the network traffic and increases the scalability of applications by eliminating unnecessary database acces.Fully transactional features and highly configurable set of options which are to deal with concurrent data access, are provided by JBoss cache in an efficient manner possible for the applications.
What is JBoss JBPM?
JBoss JBPM is a workflow and BPM engine. Enabling the creation of business processes that coordinates between people, applications and services is the functionality of BPM engine. The combination of workflow applications development with process design is a feature of JBoss jBPM. The business process is graphically represented to facilitate a strong link between the business analyst and technical developer. This feature is provided by the JBoss jBPM process designer.
How do you monitor JBoss and detect the bottleneck of an application?
Different components of the application are to be measured. This step is to find where the degradation is, whether it is external or internal and where is the appliciation spending all the time. Using Joss JMX agents and monitoring the deployed components to the application server involves in the first step.
After finding the most of the time spent by specific components or libraries or most of the resources, one can use Jprobe a specialized tool for examining the single object or the objects loaded in the memory.
How can you start a JTA transaction from a Servlet deployed on JBoss ?
JBoss registers in the JNDI tree a JTA User Transaction Object which can be user to manage a distributed transaction
What do you need to set-up a cluster with JBoss?
A: Basically starting JBoss with the “all” configuration contains everything needed for clustering:
It has all the libraries for clustering:
JGroups.jar, jboss-cache.jar
Clustered beans (cluster-service.xml)
HA-JNDI
HTTP session replications (tc5-cluster-service.xml)
Farming
HA-JMS
Which component handles cluster communication in JBoss ?
A: The JGroups framework provides services to enable peer-to-peer communications between nodes in a cluster. It is built on top a stack of network communication protocols that provide transport, discovery, reliability and failure detection, and cluster membership management services.
Is it possible to put a JBoss server instance into multiple cluster at the same time ?
A: It is technically possible to put a JBoss server instance into multiple clusters at the same time, this practice is generally not recommended, as it increases the management complexity.
What’s jBoss cache in short ?
A: JBossCache enables easy distribution of datasets across your computing environments. It is based on JGroups and enables clustering and high availability of that data. You may choose to distribute the data with JBoss Messaging to move it where it is needed for computation or event-based programming
What do you know about Seam ?
A: Built on the standards JavaServer Faces and EJB 3.0, JBoss Seam unifies component and programming models and delivers a consistent and powerful framework for rapid creation of web applications with Java EE 5.0. Seam simplifies web application development and enables new functionality that was difficult to implement by hand before, such as stateful conversations, multi-window operation, and handling concurrent fine-grained AJAX requests. Seam also unifies and integrates popular open source technologies like Facelets, Hibernate, iText, and Lucene.
Does Seam run on other application servers besides JBoss ?
A: Seam runs beautifully on other application servers – just like everything else the Hibernate team does, this is not a JBoss-only thing.
What’s JBoss JBPM ?
A: JBoss jBPM is a platform for process languages. At the base there is a java library to define and execute graphs. The actual process constructs like e.g. send email, user task and update database are defined on top of this. Every process language is made up of a set of such process constructs. And that is what is pluggable in this base library. On top of the JBoss jBPM base library, there are implemented several process languages as a set of process constructs: jPDL, BPEL and SEAM pageflow:
jPDL is a process language with a clean interface to Java and very sophisticated task management capabilities. There is no standard for Java process languages, so it is proprietary.
BPEL is a service orchestration language. As said before, in BPEL, you can write new services as a function of other services. This is typically a component of an Enterprise Service Bus (ESB).
SEAM pageflow is a language that allows for the graphically define the navigation between pages in a SEAM web application.
How do you monitor JBoss and detect the bottleneck of an application?
A: The first step is to measure the different components of your app to see where the degradation is. Is it an external resource (database, message server, etc.)? Is it internal? Where is the app spending all its time?
So the first step could be to to use JBoss JMX agents and monitor the components deployed to the application server. Once it’s clear which component or library takes most of the time or most of resource you can use a more specialized tool like JProbe and examine the single method or the single objects loaded in memory.
What version of JBoss AS do I need to run Seam?
For Seam 1.3: Seam was developed against JBoss 4.2. Seam can still be run against JBoss 4.0. The seam documentation contains instructions for configuring JBoss 4.0.
For Seam 1.2: Since Seam requires the latest edition of EJB3, you need to install JBoss AS from the latest JEMS installer. Make sure that you select the “ejb3” or “ejb3+clustering” profile to include EJB3 support. Also, the jboss-seam.jar library file from the Seam distribution must be included in each Seam application you deploy. Refer to examples in Seam distribution (inside the examples directory) to see how to build and package Seam applications.
Can I run Seam outside of JBoss AS?
Yes, you can run Seam applications in plain Tomcat 5.5+ or in the Sun GlassFish application server. To run Seam application in Tomcat, you need a number of additional library files and a few configuration files to bootstrap the JBoss EJB3 inside Tomcat. Please refer to the deploy.tomcat ANT build tarsget for the Seam booking example (in the examples/booking directory of the Seam distribution) for more on how to build a Tomcat WAR for Seam applications. Refer to this blog post on how to run Seam in Sun’s Glassfish application server.