Cognizant Interview Questions on Mulesoft

The singleton pattern is the simplest design pattern that restricts the one instantiation of a class that involves only one object that is responsible to make sure there is no more than one instance. Class instantiates itself and at the same time. It provides a global point of access to that instance and ensures the same instance can be used from everywhere

You can declare a function in the header or body of a DataWeave script by using the fun keyword.

Declaration of a function in data weave is as follows:

fun function_Name(objParameter) = { 
Variable1: objParameter.field1, 
Variable2: objParameter.field2 
} 

You can simply Invoke the function by using functionName() or functionName(arg1, arg2, argN).

In Java, serialization is a mechanism to persist java objects in a form of a sequence of bytes that includes the object’s data as well as information about the object’s type and its value. When there is a need to send your data object over a network or to store it in files you can use serialization. In other words, you can say that Serialization is the process for the conversion of an object code into a byte stream. Whereas, Deserialization is the reverse process of serialization, where the byte stream is used to recreate the actual Java object code in memory.

Middleware is software that acts as an intermediary between an operating system and software applications, especially on a network. Middleware is generally used for linking various software applications and passing data between them. Thus, It is also known as "software glue" and plumbing. For example, it can help an organization by messaging its customers, linking its payment and other systems with its customer-focused applications. Middleware enables communication and resource management for distributed applications.

MuleSoft considered that API-led connectivity is a methodical way to connect data to applications through reusable and purposeful Application programming interfaces generally known as APIs which are developed to play a specific role. APIs work for unlocking data from systems, composing data into processes, or delivering an experience.

Different types of flows in Mulesoft are listed as follows:

• Subflows
• Synchronous Flows
• Asynchronous Flows 

Subflows are synchronous flow that inherits the processing and exception handling strategy from the parent flow.

Synchronous Flows are synchronous flow with their processing and exception handling strategy.

Asynchronous Flows are asynchronous flows with their processing and exception handling strategy.

Exceptions are the runtime error for a software. Error is a measure of the estimated difference between the observed or calculated value of a quantity and its true value.

In Messaging Exception, each exception strategy can contain any number of message processors.

Different Messaging Exception strategies available in Mulesoft is as follows:

• Catch Exception Strategy
• Choice Exception Strategy
• Default Exception Strategy
• Reference Exception Strategy
• Rollback Exception Strategy

We can use the Groovy component to throw exceptions manually.

In Mulesoft, TSD or transport service descriptor is a connector used for technical configuration. TSD defines class names used for message receivers, dispatchers, and requesters.

UMO is referred to as a Universal Message Object. Mule UMO is presently an inheritance term, which was once alluded to as UMO Components are presently alluded to as Service Components.

The term transient means for a moment. You can say that it lasts only for a short time. It is sometimes referred to as impermanent.