SOA Interview Questions and Answers

The facts demonstrate that every interview is different as per the different job profiles. Here, we have prepared the significant SOA Interview Questions and Answers for beginners and experienced.

1. What is SOA?

Ans:

SOA is an architecture for building applications using reusable, interoperable services which have well defined business functionalities and can be orchestrated to achieve a specific functionality by utilizing them together.

2. What are the main features of SOA?

Ans:

SOA separates business functions into services (endpoints), which are made accessible over a network in order to allow users to combine and reuse them in their applications.

The SOA services can be developed in different languages and OS’es as long as they follow the SOA principles.

Services are unassociated and loosely coupled units that do not directly rely on each other for their full functioning. Rather than services embedding calls to each other in their source code, they use defined protocols that describe how services pass and parse messages using description metadata.

 Orchestration is a process where business functionality from various services are combined in a system fully aware of all available services and the associated metadata that defines these services and their characteristics.

3. What are the ends, contract, address, and bindings?

Ans:

The service can be made available to clients from different ends. All these services must be exposed through one of these ends. The end will consist of the following:

Contract: It is an agreement which is agreed upon between two parties. It defines how clients are expected to communicate. It specifies the different parameters and returns values that are to be used.

Address: This specifies where a user can find a service. There is an address URL which points to the location of services.

Binding: This determines how to access the end. It specifies the process for communication and how it is to be done.

4. Shed light on the various principles on which SOA is based ?

Ans:

SOA is based on the following principles. They are as follows:

• Flexible
• Re-usability
• Loose Coupling
• Interoperability

5. Do you think that Oracle Fusion is same as that of Oracle SOA?

Ans:

The answer is no due to the fact that SOA is one of the integral parts of Oracle Fusion. Moreover, SOA acts like the user interface in the Oracle Fusion platform.

6. Mention The Soa Principles?

Ans:

SOA principles were first defined by Thomas Erl. These 8 principles are underlying to any good architecture that utilizes SOA design to build their products and services:

• Standardized service contract: Services adhere to a communications agreement, as defined collectively by one or more service-description documents.
• Service loose coupling: Services maintain a relationship that minimizes dependencies and only requires that they maintain an awareness of each other.
• Service re usability: Logic is divided into services with the intention of promoting reuse.
• Service statelessness: Services minimize resource consumption by deferring the management of state information when necessary
• Service abstraction: Beyond descriptions in the service contract, services hide logic from the outside world.
• Service dis coverability: Services are supplemented with communicative meta data by which they can be effectively discovered and interpreted.
• Service autonomy: Services have control over the logic they encapsulate.
• Service composability: Services are effective composition participants, regardless of the size and complexity of the composition.

7. What Is Oracle Soa Suite Tool ?

Ans:

SOA suite tool is a middleware tool from Oracle which is based upon SOA concept comes under Oracle Fusion Middleware stack. We use this tool for integration purpose .i.e. This tool is used to integrate two system/applications etc.

8. What All Components/products Needs To Be Installed Before We Install Oracle Soa Suite Tool ?

Ans:

Following components needs to be installed before we install Oracle SOA Suite.

• JDK
• Database
• All Required Schema (Created using RCU)
• WebLogic Server

9. Why we need SOA? 

Ans:

Service is the important concept. Services can be published, discovered and used in a technology neutral, standard form by the set of protocols of the web services. Other than being just architecture, SOA is the policies, practices, and frameworks by which it is ensure the right services are provided and consumed. It becomes critical to implement processes that ensure that there are at least two different and separate processes— one for provider and the other for consumer, using SOA. The Business Service Bus is starting point for developers that guide them to a coherent set that has been assembled for their domain. This is better than leaving developers to discover individual services and put them into context

10. What are the challenges faced in SOA adoption?

Ans:

One of the challenges faced by SOA is managing services metadata. Second biggest challenge is the lack of testing in SOA space. Another challenge is providing appropriate levels of security. Interoperability is another important aspect in the SOA implementations. Vendor hype concerns SOA because it can create expectations that may not be fulfilled.

11. What is Web Service ?

Ans:

Web service is a piece of code which is available on web (internet). That code of piece can be developed in any language (java, .net etc). A client invokes the web service by sending xml message and it wait for xml response (synchronously or asynchronously).

12. What is the SOA Suite 11g Components?

Ans:

•  Oracle Adapters
•  Oracle Mediator
•  Business Events and Events Delivery Network
•  Oracle Business Rules
•  Human Workflow
•  Oracle Business Activity Monitoring
•  Oracle Enterprise Manager

13. What are the different design patterns in SOA?

Ans:

•  Synchronous
•  Asynchronous Fire and Forget
•  Asynchronous Delayed Response.

14. Enlist the Principles of SOA?

Ans:

• Loose coupling
• Re-usability
• Interoperability
• Flexible

15. In SOA do we need to build systems from scratch?

Ans:

No. If you need to integrate or make an existing system as a business service, you just need to create loosely coupled wrappers which will wrap your custom systems and expose the systems functionality in a generic fashion to the external world.

16. What is SOA registry?

Ans:

SOA registry is like a reference database of services. It describes what each service does, where they are located, and how they can communicate. It’s a central reference of meta-data for services.

17. What is SOA Workfow?

Ans:

SOA workflow allows us to define a work flow using services in the SOA registry. We will read more about BPM in further questions.

18. What is Service Broker?

Ans:

Service broker reads the work flow and takes services from the SOA registry and ties them together. Service brokers are normally middleware like EAI (Enterprise application Integration) products. You can get a list of decent EAI from Sun, Microsoft, and IBM etc.

19. What is SOA supervisor?

Ans:

SOA supervisor is a traffic cop ensuring that services do not have issues. It deals mainly with performance issues of the system so that appropriate service levels are met. If any of the services have performance problems it sends messages to the proper infrastructure to fix the issue.

20. What is singleton Property in SOA?

Ans:

In the clustered environment when the processing of the message should happen via only one SOA managed server, then the property singleton needs to be defined at the adapter level.

21. What is a reusable Service?

Ans:

It is an autonomous, reusable, discoverable, stateless functionality that has the necessary granularity, and can be part of a composite application or a composite service.

A reusable service should be identified with a business activity described by the service specifications (design-time contract).

A service’s constraints, including security, QoS, SLA, usage policies, may be defined by multiple run-time contracts, multiple interfaces (the WSDL for a SOAP Web Service), and multiple implementations (the code).

A reusable service should be governed at the enterprise level throughout its entire lifecycle, from design-time through run-time. Its reuse should be promoted through a prescriptive process, and that reuse should be measured.

22. What is composition of a Service ?

Ans:

Composition is the process by which services are combined to produce composite applications or composite services. A composite application consists of the aggregation of services to produce an enterprise portal or enterprise process. A composite service consists of an aggregation of services that produces another reusable service. It’s just like combining electronic components to create a computer motherboard, and then using that motherboard in a computer. Think of the motherboard as a reusable composite service that is a component of the computer, and of the computer as the composite application.

23. How do I integrate my Legacy applications with SOA ?

Ans:

Legacy applications are frequently at the core of your IT environment. With the right skills and tools, you need to identify discrete elements within your legacy applications and “wrap” them in standards-based interfaces and use them as services within your SOA.

24. Can you explain the difference between architecture followed in 10g & 11g?

Ans:

Given below are the differences between 10g and 11g:

In 11g, SCA architecture is followed but not in 10g.

In 11g, all of the SOA components (like BPEL, ESB, etc.) are related to project can be deployed at once as a single unit using composite.xml file. In 10g, these components need to be deployed individually to the respective servers.

App server container for 11g is Web Logic Server while for 10g is OC4J.

In 11g, Enterprise Manager takes care of all SOA components while in 10g separate consoles are maintained for each component.

25. How can a process be deployed in SOA?

Ans:

A process can be deployed using any of the below options:

• JDeveloper
• EMC(Enterprise Manager Console)
• WebLogic Scripting.

26.What are the important principles of SOA?

Ans:

The most important principles of SOA are:

• Service architecture
• Service composition architecture
• Service inventory architecture
• Service-oriented enterprise architecture

27.What is SOA record?

Ans:

An SOA record is a point from where the domain is delegated from the parent domain.

28.What is BPEL in SOA?

Ans:

is a language that facilitates the exchange of data between the web services and also for their communication. The developers use BPEL to determine how business processes having web services will run.

Apart from managing the process execution, BPEL is also used for event management and exception handling. The BPEL processes describe the order in which the processes will be called.

29.What is ESB in SOA?

Ans:

he software application within a service-oriented architecture communicates through a channel called ESB (Enterprise Service Bus). It is used to implement a different variant of the client-server architecture where any application using this system can be the client or the server.

ESB is based on a distributed computing architecture and allows high-level communications between different applications.

30.What is orchestration in SOA?

Ans:

Orchestration in SOA is the management and coordination of different services within SOA. The system experts use the service orchestration feature to automate the business processes by grouping the enterprises and applications to combine them into a single unit.

The process is made possible through the exchanging of messages in the domain layer of applications. These messages have to be exchanged according to a predefined order or business logic.

31.What is OSB in SOA?

Ans:

The OSB (Oracle Service Bus) is used for virtualizing, managing, and integrating the services in a shared architecture. It helps to manage the interactions between the applications and services.

They can be implemented through a lightweight service call. The services developed using the OSB can work as a proxy.

32.How to build a composite in SOA?

Ans:

The steps to build a composite application in SOA are:

• Open Oracle JDeveloper Studio
• Make a new Composite application.
• If this is the first application, choose SOA application from the Application Template. After accepting the package prefix defaults, click Next.
• After JDeveloper adds the necessary libraries and the composite.xml file to the project, click on Next.
• Hit Next.
• Click on Empty Composite on the SOA Configure Settings page to create an empty composite application.
• Select Save All from the File menu.

33.What is BAM in SOA?

Ans:

The Oracle BAM (Business Activity Monitoring) is used for developing personalized dashboards and monitors the business processes in a firm. This software allows the users to monitor their business activity in real time through active dashboards that will be updated without the browser being refreshed.

There are tactical dashboards that allow the users to modify the parameters to gain different analysis results from the data without a database query.

34.What is a mediator in SOA?

Ans:

The Oracle Mediator is an important component of the Oracle SOA architecture that is used for the following functionalities:

• Routing the incoming data to the external service.
• According to some filtering conditions, a specific service is called.
• Validating the incoming XML payload XSD schema validation.
• Transforming the data for the target destination through XSLT transformation.

35.How loose coupling is achieved in SOA?

Ans:

Loose coupling in SOA is an approach where the service contract is not very rigid for the people obtaining the services.

As the service contract works as a medium through which the consumers interact with the services, service loose coupling allows more flexible service contracts for their benefit. Technological independence can be achieved through the approach that helps users to get more out of the service.

36.What are Adapters in SOA?

Ans:

Adapters in SOA are used for reusing an existing component through a different interface. They help to make the existing data and functions available as services.

They can be developed whenever necessary. The Oracle SOA provides a variety of options to develop adapters. The different types of adapters are file adapter and database adapter.

37.What is Data source in SOA?

Ans:

Data source in SOA is any source of data. A database can also act as a source of data that has to be configured for SOA.

For the Weblogic Server, the data source will act as a communication channel to the underlying data. Each data source has a pool of database connections that are developed during the server start-up.

38. What are the disadvantages of SOA?

Ans:

 The main disadvantage of SOA is to see SOA as an end. Due to this developers tend to create complex unmanageable and unnecessary interconnections between resources. Instead, the developer can focus on the business problem that is existing. Another disadvantage can be that rather than solving small pieces of problem you can take the top-down approach where major companies invest and very often fail to show desired results where there is the relevant timeframe.

39. Explain what is a composition of service?

Ans:

 By using composition services are combined to produce composite applications. This application consists of an aggregation of services where an enterprise portal or process is created. A composite service consists of an aggregation of different services which will provide reusable services. It acts like combining electronics components and create reusable composite services.

40. What is ESB and where does it fit in?

Ans:

ESB stands for Enterprise Service Bus. Unlike other relationships, it provided any to any connectivity between different companies. Also, you may need to consider deployment services, IT services, etc. The SOA architecture enables SOA to meet all life’s priorities. The ESB is part of this reference architecture and provides the backbone of an SOA but it should not be considered an SOA by itself.

41. In SOA do we need to build a system from scratch?

Ans:

No, if we need to integrate any existing system you just can loosely couple wrappers which help in wrapping all customer services and expose all functionalities in a generic manner.

42. What is the difference between Monolithic, SOA and Micro services Architecture?

Ans:

Monolithic Architecture is similar to a big container wherein all the software components of an application are assembled together and tightly packaged.

A Service-Oriented Architecture is a collection of services which communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity.

Microservice Architecture is an architectural style that structures an application as a collection of small autonomous services, modeled around a business domain.

43. What is SOA [Service-Oriented Architecture]?

Ans:

 SOA is an IT architecture strategy for business solution (and infrastructure solution) delivery based on the concept of service-orientation. It is a set of components which can be invoked, and whose interface descriptions can be published and discovered. It aims at building systems that are extensible, flexible and fit with legacy systems. It promotes the re-use of basic components called services.

44. How Do You Transform An Enterprise Business In A Soa?

Ans:

•  Transforming an enterprise business to Service Oriented Architecture includes obtaining standardized service contracts, service reusability, service abstraction, service loose coupling, service composability and so on.
• Of course SOA is an architectural model agnostic to technology platforms and every enterprise can pursue the strategic goals associated with service-oriented computing using different technologies. However in the current marketplace, Web Services are probably the technology platform that better suits SOA principles and are most used to get to this architecture.

45.Why do we need SOA? 

Ans:

 Service is the important concept. Services can be published, discovered and used in a technology neutral, standard form by the set of protocols of the web services. Other than being just architecture, SOA is the policies, practices, and frameworks by which it ensures the right services are provided and consumed. It becomes critical to implement processes that ensure that there are at least two different and separate processes— one for providers and the other for consumers, using SOA. The Business Service Bus is a starting point for developers that guide them to a coherent set that has been assembled for their domain. This is better than leaving developers to discover individual services and put them into context

46.What are the Business Benefits of Service Oriented Architecture?

Ans:

SOA can help businesses respond more quickly and economically to changing market conditions. SOA can be considered an architectural evolution. It captures many of the best practices of previous software architectures. The goal of separating users from the service implementations is promoted by SOA. The goals like increased interoperability, increased federation and increased business & technology domain alignment can be achieved by SOA due to its architectural and design discipline. SOA is an architectural approach for constructing complex software-intensive systems from services. SOA realizes its business and IT benefits through utilizing an analysis and design methodology when creating services.

47.What are the IT Benefits of Service-Oriented Architecture?

Ans:

IT benefits of SOA are:

• The ability to build composite applications is provided.
• Business services are offered across thvided
• Provides truly real-time decision-making applications.
• Reliability is enhanced
• It is not necessary that Services be at a particular system or network
• The approach is completely loosely coupled
• Hardware acquisition costs are reduced
• At every level there’s Authentication and authorization support
• Existing development skills are leveraged
• Provides a data bridge between incompatible technologies
• The search and connectivity to other services is dynamic

48. What is choreography? How does it differ from orchestration? 

Ans:

In choreography there is no business process to control the integration between the systems; each system will directly integrate with one another in sequence where as in Orchestration there is a business process which controls all the services (Source/Target) which is part of the integration. 

49. What Are Dspmaxthread And Recieverthread Properties? Why Are They Important?

Ans:

Receiver Threads property specifies the maximum number of MDBs that process Async across all domains. Whereas the dspMaxThread are the maximum number of MDBs that process Async and threads that operate across a domain. So, we need to ensure that the dspMaxThread value is not greater than Receiver Threads.

50. What is Tweening?

Ans:

 Also Known as in-betweening, it is the process of creating intermediary frames among two images to provide the appearance that the first image develops efficiently into the second image. It is a key process which is used in all types of animations. Refined animation software permits you to find particular objects in an image and describe how they will be able to move and change throughout the tweening process.

51. What Is The Purpose Of Oracle Service Bus?

Ans:

•  Oracle Service Bus provides standalone service bus capabilities, enabling separation between application developers and target systems or services. Oracle Service Bus receives messages through a transport protocol such as HTTP(S), JMS, File, and FTP, and sends messages through the same or a different transport protocol.
• Service response messages follow the inverse path. Oracle Service Bus handles the deployment, management, mediation, messaging, security and governance of implementing SOA to enterprise applications.

52. What Is The Purpose Of Business Events?

Ans:

 Business events are messages sent as the result of an occurrence or situation, such as a new order or completion of an order. In Oracle SOA Suite, the mediator service component subscribes or publishes events. When an event is published, other applications can subscribe to it.

53. What is SOA governance? What are its functions? 

Ans:

• Service-Oriented Architecture (SOA) governance is a concept used for activities related to exercising control over services in an SOA Some key activities that are often mentioned as being part of SOA governance are: 
• Managing the portfolio of services: This includes planning development of new services and updating current services. 
• Managing the service lifecycle: This is meant to ensure that updates of services do not disturb current services to the consumers. Using policies to restrict behavior: Consistency of services can be ensured by having the rules applied to all the created services. Monitoring performance of services: The consequences of service downtime or underperformance can be severe because of service composition. Therefore action can be taken instantly when a problem occurs by monitoring service performance and availability. 

54. What is endpoint virtualization? 

Ans:

•  Generally a service bus is used for endpoint virtualization and in 11g stack; Oracle Service Bus (OSB) is the primary service bus. In exposed proxy’s message flow, it can route the request to any of your environment’s actual (physical) service on the basis of whatever logic.
• Mediator can also be used to expose the service and in mediator routing rule, it can be routed to actual service. 

55. What are DVM’s and how are they helpful in SOA?

Ans:

 DVM-Domain Value Map is static mappings between a source and target system which can be used in transformations. The value can be changed via SOA composer. 

56. What is the difference between XREF and DVM? 

Ans:

• XREF- It is dynamic since the values to the XREF can be populated dynamically and it is stored in the XREF_DATA table in the SOA Dehydration store. 
• DVM- Domain Value Map is static mappings between a source and target system which can be used in transformations. 

57. What is Dehydration store? 

Ans:

 Dehydration store is the database where the instances get stored when it gets dehydrated by the process on the occurrence of non-idempotent activities and also stores the information on the long running processes. 

58. What is Decision service? 

Ans:

 Oracle SOA Suite provides support for Decision components that support Oracle Business Rules. A Decision component is a mechanism for publishing rules and rule sets as a reusable service that can be invoked from multiple business processes. These rules can be changed without redeploying the code. 

59. Why do we use BPEL and OSB? 

Ans:

 OSB is the light-weight service bus wherever there is not much business logic involved and there is a need to just get the message routed between the systems OSB is used whereas when there is more business logic involved in the process, then BPEL will be used. 

60. What is MDS? 

Ans:

• MDS –Metadata Store 

Wsdl and Schemas to be used in the process can be published to the MDS and get it used in the code by referring the artifacts from the MDS 

Advantages: 

• JAR (Deployment unit) size will be reduced.
• Duplication of the artifacts can be avoided between the services.

61. What is a XA data source? How it differs from a non-XA data source? 

Ans:

 An XA transaction involves a coordinating transaction manager, with one or more databases (or other resources, like JMS) all involved in a single global transaction. Non-XA transactions have no transaction coordinator, and a single resource is doing all its transaction work itself (this is sometimes called local transactions). 

62. How can we secure our web services using Oracle SOA Suite? 

Ans:

 When accessing the services should be restricted to the group,then service should be secured via WSM (Web service Manager). 

63. How to deploy an XSL file without deployment of BPEL Process? 

Ans:

 We will directly deploy the XSLT, options: – 

• Using ANT script by file replacement in TMP folder. 
• By creating a folder in BPEL PM Installation folder and specifying its location in our BPEL code with http call and replacing our xslt to that location. 

64. What is HA File and FTP Adapters? 

Ans:

 In the clustered environment, File and FTP adapters should be used as HA

(High-Availability) 

• Inbound: It is controlled by Control Files and avoids the race between the manages servers in reading the files where the reference of the files read by the managed servers will be maintained in the control directory. 
• Outbound: It is controlled by DB Mutex table exist in the SOA dehydration store and this avoids duplicated been written to the same file when all the managed servers in the clusters process the same messages. 

65. What is a pick activity? Can I have a pick activity with no onMessage branch? 

Ans:

 Pick activity picks the messages from service (Source) which has multiple operations or the BPEL process needs to receive the messages from multiple source systems. Pick activity should have at least one Message branch. 

66. What is a flow activity? What is a flowN activity and how does it leverage the flow activity? 

Ans:

Flow activity is used, when parallel execution of the flow is needed and to use this property “non blocking invoke should be set as true “at the partner link level and no. of execution of parallel flow is defined and static. Where as in Flown the no. of execution of parallel flow is not static and it is determined during run time. 

67. What do you mean by non-idempotent activity? Which all activities are non-idempotent by default? 

Ans:

 Activities like Pick, Wait, receive, reply and checkpoint() are called non-Idempotent activity and during the execution of the process whenever these activities are encountered then it gets dehydrated to the dehydration store. 

68. How can we embed or use Java code in BPEL? 

Ans:

Using JAVA embedding activity in BPEL, Java code can be embedded in BPEL and can be used. 

69. How does pick activity differ from a receive activity? 

Ans:

 Pick activity can act as a multiple receive activity in some business scenarios. If we have two inbound operations and both can trigger the bpel process then we will go with pick activity as we can’t have two receive activity with create Instance box checked. 

70. How can we make a partner link dynamic? 

Ans:

 If we have to send the request to a different service which has the same wsdl then dynamic partner link will be used and using addressing schema we can set the endpoint dynamic to send the request to the desired service. 

71. What is a nonBlockingAll property? 

Ans:

 Non- blocking invoke is used when Parallel flow needs to be executed where new thread will be created for each invoke activity and which will execute simultaneously. 

72. What is getPreference property? How do we set it and what advantage it provides? 

Ans:

 Hard coding is not a good practice, so to avoid hard coding preference variables can be used and the value of the preference variable is accessed using getPreference().The preference variable value can be changed without re-deploying the code via em console MBean property. 

73. How can we improve the performance of an XSL file? 

Ans:

 By avoiding use of various if statements and using choose and by using for-each group in place of for-each. 

74. How do we handle transactions in BPEL?

Ans:

•  Property needs to be defined to start the new transaction or to continue with the same transactions 
• Property Name: Transaction and if this has value as required then the BPEL process will be continued in the same transaction where as if the value is defined as requiresnew then it will start the new transaction. 

75. What are transient and durable BPEL processes? 

Ans:

• Durable:-It is long running process and initiated through a one-way invocation and do incur one or more dehydration points in the database during execution Ex: Asynchronous 
• Transient:-It is a short-lived process, request-response style processes and do not incur dehydration during their process execution Ex: Synchronous.

76. When will you go for the Sync process? 

Ans:

Whenever the service returns the response in a few seconds, it is recommended to go for synchronous BPEL process if not the BPEL process should be Asynchronous the reason is calling application can’t proceed further in case of synchronous process. 

77. What is a syncFileRead operation? Is it an inbound or an outbound operation? Can my process begin with syncFileRead operation? 

Ans:

 When a file has to be read in the middle of the BPEL process, then we will use syncFileRead Operation, means some process should initiate the file read process and it is an outbound operation and process can’t begin with Sync File read. 

78. Can we use a File Adapter to get a file without reading its content? 

Ans:

 Yes, by selecting the Do not read file content check box in the Jdeveloper wizard while configuring the “Read operation.” 

79. How to increase performance increase in bpel (Db Adapter/file adapter)? 

Ans:

We can increase the performance by writing indexes and sequences. 

(Or) Go to application server —-> Configurations —–> Change Xml file 

80. Explain error handling in BPEL and what is an error handling framework? How is an error handling framework better than simple error handling in BPEL? 

Ans:

EHF –Whenever any error thrown by the BPEL process/Mediator then EHF will check whether exist in Fault-Bindings.xml files and if so then the action in the Fault-Policy.xml file will be taken and if the action is not found then the fault will the thrown and it will be handled in the catch block. 

81. How do we resubmit a faulted process?

Ans:

• Scenario A: The BPEL code uses a fault-policy and a fault is handled using the “ora-human-intervention” activity, then the fault is marked as Recoverable and the instance state is set to “Running”. 
• Scenario B: The BPEL code uses a fault-policy and a fault is caught and re-thrown using the “ora-rethrow-fault” action, then the fault is marked as Recoverable and the instance state is set to “Faulted”; provided the fault is a recoverable one (like URL was not available). 

82. What are Predefined errors in BPEL?

Ans:

• Custom errors
• Timed out errors
• BPM errors
• Validation Errors

83. What is a throw activity? What is it? 

Ans:

Throw activity will explicitly throw the fault and this fault will get caught by the catch block and the corresponding actions will get executed. 

84. Explain About Web service?

Ans:

Web service is a type of software system which is used for exchanging the data and using information from one machine to another machine through a network. Generally Web services based on the standards such as TCP/IP, HTTP, Java, HTML and XML. Web services are pure xml based which is used for exchange information through the Internet to direct application to application interaction. These systems include programs, objects, messages or documents. Many software applications written in various programming languages and running on various platforms can use web services to exchange data over computer networks. You can develop Java-based web services on Solaris and that is accessible from your V.B Program that runs on windows. 

85. What is the Difference between URI and URL? 

Ans:

 A URI is an identifier for some resource, but a URL gives you specific information as to obtain that resource. A URI is a URL and as one commenter pointed out, it is now considered incorrect to use URL when describing applications. Generally, if the URL describes both the location and name of a resource, the term to use is URI. Since this is generally the case most of us encounter every day, URI is the correct term. 

86. What is a Mediator? 

Ans:

•  The Mediator is in charge of interconnecting, within an SOA composite application, components that expose different interfaces. In addition, the Mediator can perform duties such as filtering and making routing decisions. 
• The composite editor in Jdeveloper gives you the flexibility to define the interface now, to choose an existing interface, or to define the interface later as you wire components to the Mediator. Transforming data from one representation to another is, along with routing, one of the key functions of the Mediator. 

87.What are the main benefits of SOA ?

Ans:

• SOA helps create greater alignment between IT and line of business while generating more flexibility – IT flexibility to support greater business flexibility. Your business processes are changing faster and faster and global competition requires the flexibility that SOA can provide.
• SOA can help you get better reuse out of your existing IT investments as well as the new services you’re developing today. SOA makes integration of your IT investments easier by making use of well-defined interfaces between services. SOA also provides an architectural model for integrating business partners’, customers’ and suppliers’ services into an enterprise’s business processes. This reduces cost and improves customer satisfaction

88. What is BPEL Process in SOA ?

Ans:

(Business Process Execution Language) BPEL Process is a language used for the composition, orchestration and coordination of webservics.

Enterprise Information system can improve the efficiency of businesses through the automation of business processes. The objective of almost every company is that the application it uses should provide comprehensive support for business processes. It means that applications should align with business processes closely. 

BPEL improves and extends the flexibility of earlier integration methods and distributed architectures, and focuses on the reusability of existing applications and system, efficient interoperability’s and application integrations and the composition of business processes out of services provided by applications. Another important objective of SOA is also the ability to apply changes in the future in a relatively easy and straightforward way. 

BPEL is the one of the most popular, commonly accepted specialized language for business process, BPEL is a special language, designed to execute business processes using a special server. BPEL process provide good environment where business processes can be developed in an easy and efficient manner, directly executed, monitored and quickly adapted to the changing needs of enterprises without too much effort. 

89. What is/was the motivation behind BPEL? How does it differ from other/past attempts/technologies aimed at the integration/business process problem? Can you talk briefly about the evolution of BPEL?

Ans:

Orchestrating a set of services into an end-to-end process flow entails a new set of technical requirements (binding to heterogeneous system, synchronous and asynchronous message exchange patterns, data manipulation, flow coordination, exception management, undeterministic events, compensating transactions, side-by-side versioning, in-flight instance management and auditing). The goal of BPEL is provide a richer and yet simpler abstraction/standard for addressing those requirements. Although it is a fairly new standard, it leverages from 10+ years of research and development Microsoft and IBM invested in XLANG and WSFL.

90.What is orchestration? What does it mean to build composite applications? Why would anyone want to?

Ans:

Existing systems are not going away. Yet enterprises need to build new applications that can leverage the functionality encapsulated in those existing systems. The notion of a composite application is based around the idea of building new applications by wiring together existing building blocks. Orchestration plays an important role in this picture because it is the glue that coordinates the execution of each discrete service. A good orchestration server needs to be reliable, scalable and render the BPEL process logic with very high fidelity.