Frequently Asked MuleSoft Interview Questions 2019

The demand for MuleSoft's tools has seen exponential growth in recent years. The recent Mulesoft acquisition by Salesforce for $6.5 billion in its biggest-ever deal is also an example of the increasing relevance of MuleSoft technologies. Do you know MuleSoft's suite of tools is the most popular integration solution used by over 1,400 companies around the world?

Against this backdrop, the demand for professionals fluent in MuleSoft technology has grown tremendously. If you are a fresher looking to step up your career or an experienced professional seeking to brush up your knowledge of Mule ESB, the following interview questions will prove highly effective.

Frequently Asked MuleSoft Interview Questions 2019

Define Mule ESB

It is an integration platform and a lightweight enterprise service bus (ESB) based on Java. It enables developers to easily and quickly connect applications and exchange data. With Mule ESB, developers can easily integrate existing systems irrespective of how different are the technologies that the application use such as Web Services, HTTP, JDBC, JMS and the like.

What is the benefit of using Mule ESB?

Mule ESB is an integration framework that is lightweight and highly scalable. It enables developers in starting small applications and also in connecting different applications. With Mule managing the exchanges between components and applications transparently and ESB taking care of a variety of applications, it is easy to integrate third-party applications with the help of Mule.

What are the various types of Exception Handling?

• Global Exception Handling
• Catch Exception Handling
• Choice Exception Handling
• Default Exception Handling
• Rollback Exception Handling

What are the characteristics of Mule ESB?

An ESB is used for the purpose of integration with an approach that is service-oriented. Its features include:

• Message Routing Service
• Message Transformation Service
• Set of Service Container
• Web Service Security

In Mule, how do you develop and consume SOAP services?

SOAP services can be created just like how we create a Mule project by using RAML. The difference here is that we need Concert WSDL importing rather than RAML. And SOAP services can be consumed by using our Mule flow CXF component or Web Service Consumer.

How can you find out whether your project requires ESB?

As every project might not require an ESB, you should analyze first to see if your project might benefit from ESB implementation. Certain things that should be at the front of your mind while you analyze the need for ESB are:

• If the project requires integration of more than 3 applications or services and if communication between two application is needed, it would be enough to use point to point integration
• Sometimes there will be a need for you to scale the project in the future where there might arise a need to interact with multiple services. This is required only by a few projects that perform heavy tasks
• If the project requires message routing abilities such as aggregating and forking message flows. This feature is not necessary for all projects
• You should have clarity on the architecture of the thing that needs to be achieved. A simple POC integration of small parts to find out the benefits is much better
• As most of the ESBs are on the expensive side, first evaluate whether your project budget permits ESB use

Name the various kinds of Primitives that are used in Mediation.

The following are the various kinds of primitives in mediation

• Endpoint Lookup
• Service Invoke
• DB lookup
• Data Handler
• Type Filter
• Message Element Setter
• Custom MediationFan-out
• Fan-in
• Header Setters
• Message Logger
• Even Emitter
• XSLT
• BO MapMessage Filter
• Fail
• Stop
• Sub Flow

Name the various ESBs that are in the market

There are different ESBs in the market, both licensed and open source. They are:

• JBoss Fuse ESB
• Mule ESB
• Talend

What do you know about Mule's shared resources?

Connectors can be made into reusable components. For that, you first need to define them as common resources and then expose them to all applications that have been deployed under the same domain. Such resources are called shared resources. Shared resources need to be defined inside Mule Domain Project and need to be referred to every one of the projects that are intended to incorporate the elements in it.

What are the core principles of ESB Integration?

Transportation — Transport protocol negotiation between different formats including JMS, JDBC, HTTP, etc.

Transformation — Transformation of data between certain data formats as needed by every ESB connector individually

Non-functional consistency — The way monitoring and security policies are applied as well as implemented should be consistent

Mediation — This involves offering many different interfaces to:

• Enable different channels to the same unlying component implementation
• Support different service versions for backwards compatibility

What are the different types of variables in Mule?

The different types of Mule variables are:

• Record variable
• Session variable
• Flow variable

What are the different kinds of Flow Processing Strategies?

The following are the six kinds of Flow Processing Strategies:

• Thread Per Processing Strategy
• Custom Processing Strategy
• Queued Asynchronous Flow Processing Strategy.
• Asynchronous Flow Processing Strategy
• Synchronous Flow Processing Strategy
• Queued Flow Processing Strategy
• Non-blocking Flow Processing Strategy

Thanks for reading!