Interview Questions.

Q1. What Are Needed To Set-up A Cluster With Jboss ?

Basically beginning JBoss with the ’all’ configuration includes the whole lot needed for clustering:

It has all the libraries for clustering:

JGroups.Jar, jboss-cache.Jar

Clustered be (cluster-provider.Xml)

HA-JNDI

HTTP consultation replications (tc5-cluster-carrier.Xml)

Farming

Q2. What Is Global In Drl File?

Global is the key-word used in drools to outline a global variable. Global variable is the one on the way to be seen to all the regulations internal a DRL file.

Globals must be used very cautiously in a DRL report, because the adjustments in a international variable are not notified to the operating reminiscence. For instance, you are using a listing variable as a global and in any rule you're adding a value in a list and in a single specific rule, you are checking if list size() > zero, then in this case rule won't fire. Global variable may be used for any form of item.

Q3. Can I Run Seam In A J2ee Environment?

Yes, as of Seam 1.1, you can use Seam in any J2EE application server, with one caveat: you may no longer be able to use EJB 3.Zero consultation be. However, you could use either Hibernate or JPA for endurance, and you may use Seam JavaBean additives in place of session be.

Q4. Is The Graphical Process Designer (gpd) Only Usable In Eclipse? Is There A Way To Use It Standalone?

The jBPM GPD is an eclipse plugin that goals utilization by means of a couple of roles. Both the business analyst and developer are able to use the identical device in special ways. The predominant reason why we assume it is essential to combine the ones  in a single single surroundings is due to the fact in many groups, these  roles are carried out through one man or woman.  Then it will become very important that the tool can guide each roles and step by step shift from being a diagramming tool to an implementation tool.

Q5. 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 in which the degradation is, whether it's far external or internal and wherein is the utility spending all of the time. Using Joss JMX agents and monitoring the deployed additives to the utility server includes within the first step.

After locating the most of the time spent by using specific additives or libraries or maximum of the sources, possible use Jprobe a specialised device for inspecting the unmarried object or the items loaded in the memory.

Q6. What Is The Difference Between A Local-tx-datasource And A Xa-datasource? Can You Use Tractions In Both?

A neighborhood-tx-datasource identifies a information source that uses tractions, even distributed tr actions in the nearby utility server, however doesn’t use dispensed tractions amongst more than one software servers. An xa-datasource then again identifies a statistics source that makes use of disbursed traction among multi-ple utility servers.

Q7. What Version Of Jboss As Do I Need To Run Seam?

For Seam 1.3: Seam become evolved against JBoss four.@Seam can still be run against JBoss 4.@The seam documentation contains commands for configuring JBoss four.0.

For Seam 1.2: Since Seam calls for the ultra-modern version of EJB3, you want to put in JBoss AS from the trendy JEMS installer. Make positive which you select the “ejb3” or “ejb3+clustering” profile to encompass EJB3 guide. Also, the jboss-seam.Jar library document from the Seam distribution need to be protected in each Seam software you set up. Refer to examples in Seam distribution (within the examples directory) to see how to build and package Seam applications.

Q8. Is It Possible To Put A Jboss Server Instance Into Multiple Cluster At The Same Time ?

It is technically possible to place a JBoss server instance into multiple clusters on the equal time, this practice is typically no longer recommended, because it will increase the control complexity.

Q9. Is The Graphical Process Designer (god) Only Usable In Eclipse? Is There A Way To Use It Standalone?

The jBPM GPD is an eclipse plugin that goals usage through multiple roles.  Both the business analyst and developer are able to use the equal tool in one-of-a-kind ways.  The fundamental cause why we think it's miles important to integrate those  in a single unmarried surroundings is because in lots of teams, these  roles are carried out via one individual.  Then it turns into very vital that the device can assist each roles and gradually shift from being a diagramming device to an implementation device.

Q10. What Does Jbpm Do?

This business method lets in you to version your business goals via describing the steps that want to be done to gain that intention and the order, the use of a float chart. This greatly improves the visibility and agility of your business common sense, outcomes in higher-level and domain-precise representations that may be understood by way of commercial enterprise users and is less difficult to screen.The core of jBPM is a mild-weight, extensible workflow engine written in pure Java that lets in you to execute commercial enterprise approaches using the modern day BPMN 2.0 specification. It can run in any Java environment, embedded in your application or as a carrier.

Q11. Where Can I Find Seam Examples And Documentation?

The supply code and build script of all Seam instance programs are covered inside the examples listing of the Seam distribution.

Q12. What Are The Advantages Of Jbpm5?

JBPM5 affords a specific computational model for enterprise manner and rule. This version is based on a understanding-oriented technique, where the application isn't always manner-orientated or rules-orientated, however the cease customers can definitely choose between one of a kind paradigms to symbolize their business good judgment. All tools and interfaces the user is confronted with help this concept of a unified surroundings at some stage in the entire information lifestyles cycle.

Q13. What Is Jboss Cache In Short?

JBossCache allows smooth distribution of datasets across your computing environments. It is based on JGroups and enables clustering and excessive availability of that facts. You may also pick out to distribute the information with JBoss Messaging to move it where it's far wanted for computation or occasion-based programming.

Q14. What Do You Know About Seam?

Built on the requirements JavaServer Faces and EJB three.0, JBoss Seam unifies aspect and programming models and grants a regular and effective framework for speedy creation of internet programs with Java EE 5.@Seam simplifies web software improvement and allows new functionality that became difficult to put in force by hand earlier than, together with stateful conversations, multi-window operation, and managing concurrent nice-grained AJAX requests. Seam also unifies and integrates famous open supply technologies like Facelets, Hibernate, iText, and Lucene.

Q15. How Can You Start A Jta Traction From A Servlet Deployed On Jboss?

JBoss registers within the JNDI tree a JTA UserTraction Object which can be person to manage a allotted traction.

Q16. Does Seam Run On Other Application Servers Besides Jboss?

Seam runs fantastically on different software servers – just like the whole lot else the Hibernate team does, this is not a JBoss-only issue.

Q17. What Is Bpm?

BPM stands for Business Process Management.  There are 2 exclusive elements of BPM: BPM as control subject and BPM as software program engineering.  The BPM providers have long time attempted to make abstraction of these 2 wonderful components.  That direction result in greater confusion then whatever else.BPM as a control subject is the duty of every strategic govt manager.  It’s to make certain that the employer performs well in their core commercial enterprise strategies.  This involves understanding what values the organization offers and the way the ones are executed.  This me analyzing, documenting and improving the manner that people and structures paintings collectively.  As part of that paintings, it’s useful to paintings with fashions and diagrams.   BPMN diagrams express the execution flow of the stairs to accomplish a positive aim.   Important to note that these fashions are used for people to humans verbal exchange.  They can be underspecified, which me that they are able to include valuable high degree statistics without which include useless information.  Such underspecified method models are also called summary business techniques.

Q18. Is It True That Seam Only Works With Jsf?

Seam simplest helps JSF as a view framework right now. We plan to assist different web frameworks inside the destiny. We like JSF as it is part-primarily based UI framework, which fits virtually nicely with Seam’s factor-based totally technique to commercial enterprise items and persistence objects. Seam made a main development to JSF by doing away with almost all XML configuration for backing be — you may now outline lower back be from POJOs or EJB3 components using easy annotations. We endorse you operate Facelets, instead of JSP, with JSF. Facelets offer a effective templating framework, better utility performance, and lets in us to put in writing a lot less complicated JSF pages.

Q19. What Is Jta?

Java Traction API (JTA) specifies popular Java interfaces among a traction supervisor and the events involved in a distributed traction gadget: the aid manager, the utility server, and the tractional programs.

The Javaâ„¢ Traction API (JTA) allows applications to perform distributed tractions, that is, tractions that get admission to and replace statistics on two or more networked laptop sources.

The Java Traction API includes 3 elements: a high-level software traction demarcation interface, a high-degree traction supervisor interface meant for an application server, and a popular Java mapping of the X/Open XA protocol meant for a tractional resource manager.

Q20. Do You Know How You Could Add Support For Web Service Tractions?

JBossTS helps Web Services tractions, inclusive of extended traction models designed specially for loosely-coupled, long jogging enterprise processes. J2EE tractions can combine seamlessly with Web Services tractions the usage of our integrated, bi-directional traction bridge. Interoperability with many other companies is furnished out-of-the-box and JBoss is an active player in those standards.

Q21. Can I Use Ajax With Seam?

Yes, Seam presents incredible assist for AJAX. First, Seam helps the ICEfaces and Ajax4JSF Ajax element libraries for JSF. If you select a extra “old school” method, Seam gives a whole JavaScript remoting framework which lets you call Seam components and subscribe to JMS topics without delay from the purchaser. Please refer to the Seam remoting example application on how to use AJAX remoting to enforce a chat room.

Q22. What Is The Difference Between Hibernate And Ejb 3? Do Not You Think Ejb 3 Is Just A Clone Of Hibernate?

The notion of EJB3 as being a easy similar to Hibernate is based on developer familiarity with Hibernate and a similarity of naming, in addition to common purpose, and that Hibernate is morphing itself into an EJB3 implementation based totally on the paintings going into the specification, now not the opposite way round.

EJBs are purported to be additives, within the feel that they’re not simply one magnificence, but a hard and fast of instructions, descriptors and usage and management contracts. All of this with a view to allow a field (JBoss, Weblogic, and many others.) to provide services to those additives, and as a way to reuse and distribute this components.

This offerings are, amongst others, tractions, concurrent access control, protection, instance pooling, etcetera.

Hibernat is “simply” an ORM (Object/Relational Mapping) device. Quick and dirty, this me you could shop an object tree belonging to an magnificence hierarchy in a relational DB with out writing a unmarried SQL question. Quite cool, IMO. But no traction manipulate, no instance pooling, no concurrency manipulate, and virtually no protection.

Q23. Can I Run Seam With Jdk 1.Four And Earlier?

No, Seam only works on JDK 5.Zero and above. It makes use of annotations and other JDK 5.Zero features.

Q24. What Is Jbpm?

JBPM is a versatile Business Process Management (BPM) Suite. It makes the bridge between enterprise analysts and developers. Traditional BPM engines have a focus that is limited to non-technical humans simplest. JBPM has a dual cognizance: it gives method management capabilities in a manner that both enterprise customers and builders adore it.

Q25. Which Jdk Is Needed To Run Seam?

Seam handiest works on JDK 5.Zero and above. It uses annotations and other JDK five.0 features.

Q26. What Is Drools?

Drools is a Business Rules Management System (BRMS) solution. It presents a core Business Rules Engine (BRE), a web authoring and guidelines management software (Drools Workbench) and an Eclipse IDE plugin for center improvement.

Q27. Where To Use Global Variable?

Consider a state of affairs, in which in the regulations there may be a requirement for database connection object. In this situation, the DB Connection item may be inserted as a global variable inside the running reminiscence and the relationship item will be visible to all the rules in that DRL record.

Q28. Which Component Handles Cluster Communication In Jboss?

The JGroups framework offers services to enable peer-to-peer communications between nodes in a cluster. It is built on top a stack of network verbal exchange protocols that offer trport, discovery, reliability and failure detection, and cluster club management offerings.

Q29. Which Hibernate Object Wraps The Jdbc Connection?

The Session interface wraps a JDBC Connection. This interface is a single threaded item which represents a single unit of work with utility and persistent database. It’s retrieved by means of the SessionFactory’s openSession() method.

Q30. What Is A Rule Engine?

A rule engine may be regarded as an advanced if/then declaration interpreter. The if/then statements that are interpreted are known as guidelines.

Q31. Can I Unit Test Seam Applications Without Starting The Application Server?

Yes, Seam offers its personal integration take a look at framework primarily based on TestNG. You can effortlessly mock all Seam offerings the usage of the ones facilities without ever loading an utility server or a database. Refer to the check example ANT goal in the Seam reserving example utility for extra details.

Q32. Is The Session Factory Thread Safe?

Yes: that is many threads can get admission to it cuncurrentely and request for periods. It holds cached facts that has been study in a single unit of labor and may be reused in a destiny unit of labor. Good exercise is to create it whilst the software is initialized.

Q33. Mention The Main Features Of Jbpm5?

Visual user friendly editor: Users can pick between a web based totally editor (Oryx) or an Eclipse based one. You can pick out depending on the give up user and in case you are going to use the task’s BRMS (Guvnor) in which you may keep all your commercial enterprise belongings together with approaches, regulations and documentation in a significant location.

BPMN2 wellknown aid: This permits you to pick a exceptional editor to generate your enterprise techniques and run them in JBPM@There’s no 100% help for the same old yet, however development is being made on this matter.

Human Task features: JBPM5 has a local perception of a Human challenge, an pastime that desires to be completed through an actual man or woman and has a lifecycle: it can be started, suspended, finished, and so on. It is also a preferred spec.

Process Console: You can have interaction with the engine through this console in which you can start tactics, complete human duties, fill bureaucracy, etc. This console is GWT based totally.

JPA endurance approach: it permits you to pick any database and persistence schema to keep the processes variables and history log.

Designed for area unique workflows: this me that you can create your personal enterprise area precise tasks along with (Receive Claim, Approve loan , Check Blood Pressure, and so on) and construct a palette for stop users this is very herbal to their surroundings. This is combination with a visual modeler is a quite explosive combination, permitting a completely efficient as-is procedure knowledge accumulating and to-be system design across an entire line of enterprise.

Business Activity Monitoring built in: what’s a BPM’s worth if you could’t display your processes? JBPM5 allows you to make reports (which include tables and charts) over the manner instance information and records log. This is useful for higher stage customers that as C-stage govt who need system statistics to make decisions. It also allows you to apply BIRT to generate your reports, so your creativeness is the limit in relation to the amount of data you can gift.

Console Custom paperwork integration: By the use of a template framework, JBPM5 lets in your users to have interaction with their tactics using  the equal console to start the procedure and make actions to it within a custom shape for every interest. For instance you may have a purchaser’s facts amassing interest in your system and a custom shape can be constructed to fill that records into the workflow.

Powerful rules language: To make choices inside the process you may use Drools rule syntax to as an example change a route in step with a enterprise situation, which includes a credit score rating.

Q34. What If You Need To Span Your Traction Across Multiple Servlet Invocations?

You can’t with a Servlet. A JTA traction must start and finish inside a single invocation (of the carrier() approach). You have to keep in mind using a Stateful SB. In a SFSB with a JTA traction, the affiliation between the bean instance and the traction is retained across more than one client calls.

Q35. Explain The Difference Between Stringbuilder And Stringbuffer Class?

StringBuilder is unsynchronized whereas StringBuffer is synchronized. So while the application desires to be run handiest in a single thread then it's miles better to use StringBuilder. StringBuilder is more efficient than StringBuffer.

Q36. What Optimization Could I Use If The Ejb Container Is The Only Point Of Write Access To The Database?

You may want to activate the “Commit Option A” this is the box caches entity bean state among tractions. This choice assumes that the container has exclusive get right of entry to to the persistentstore and therefore it doesn’t want to synchronize the in-reminiscence bean kingdom from the persistent shop at the beginning of every traction.

Q37. What Are The Advantages Of Rule Engine?

Advantages of Rule Engines:

Greater flexibility: maintaining your policies right into a Knowledge base can help you adapt without difficulty your decisions whilst they're converting.

Easier to comprehend: Rules are easier to recognize than procedural code so that they may be successfully used to bridge the gap between commercial enterprise analyst and builders.

Reduced complexity: When embedding masses of decision factors on your procedural codes it can easily flip your utility right into a nightmare. On the alternative hand policies can take care of a good deal better increasing complexity due to the fact they use a regular representation of enterprise policies.

Reusability: By preserving policies are saved in one vicinity results in a more reusability of your enterprise regulations. Also, traditional procedural code frequently impose useless versions of base rules which are therefore more difficult to reuse in different contexts.