Integration / Mule ESB Interview Questions
1. What is Mule ESB?
Mule ESB also known as mule, is a lightweight Java-based enterprise service bus (ESB) and integration platform that allows developers to connect applications together quickly and easily, enabling them to exchange data. Mule ESB enables easy integration of existing systems, regardless of the diffe...
2. Explain Enterprise Service Bus (ESB).
An enterprise service bus (ESB) is software architecture for middleware that provides fundamental services for more complex architectures. For example, an ESB incorporates the features required to implement a service-oriented architecture (SOA). In a general sense, an ESB can be thought of as a m...
3. Advantages of Mule ESB.
Service creation and hosting exposes and hosts reusable services, using the ESB as a lightweight service container. Service mediation shields services from message formats and protocols, separate business logic from messaging, and enable location-independent service calls. Message routing route, ...
4. Why Mule is preferred than other ESB implementations?
Mule is lightweight but highly scalable, allowing you to start small and connect more applications over time. The ESB manages all the interactions between applications and components transparently, regardless of whether they exist in the same virtual machine or over the Internet, and regardless o...
5. When do we need ESB?
Mule and other ESBs offer real value in scenarios where there are at least a few integration points or at least 3 applications to integrate. They are also well suited to scenarios where loose coupling, scalability and robustness are required.
6. How Mule ESB works?
Mule is based on the concept of Event Driven Architecture (EDA), works by responding to messages initiated by external resources (that is, events). Mule applications accept and process events as messages through several message processors plugged together in a flow. Alternatively, large or stream...
7. Explain Flow in Mule ESB.
A flow is the construct within which you link together several individual elements to handle the receipt, processing, and eventual routing of a message. A Flow is a sequence of message-processing events. A message that enters a flow may pass through a wide variety of processors. In the example di...
8. Explain Batch Jobs in Mule ESB.
A batch job is a top-level element in Mule ESB which exists outside all Mule flows. Batch jobs split large messages into records which Mule processes asynchronously; just as flows process messages, batch jobs process records. A batch job contains one or more batch steps which, in turn, contain an...
9. What are Message Sources is Mule ESB?
Message sources in Mule are usually Anypoint Connectors, elements which provide connectivity to a specific external source, either via a standard protocol (such as HTTP, FTP, SMTP ) or a third-party API (such as Salesforce.com, Twitter, or MongoDB .)
10. Explain Mule Expression Language (MEL).
MEL is a lightweight, Mule-specific expression language that you can use to access and evaluate the data in the payload, properties and variables of a Mule message. Accessible and usable from within virtually every message processor in Mule, MEL enables you to quickly and elegantly filter, route,...
11. What are the other available ESB implementations apart from Mule?
There are many open source and commercial ESB implementations available. All major JEE vendors (BEA, IBM, Oracle, Sun) have an ESB in their catalog. It is unremarkably based on their middleware technologies and is usually at the core of a much broader SOA product suite. There are also some commer...
12. Difference between ESB and JMS.
ESB provides the middleware and interfaces that allow businesses to connect their applications without writing code. JMS provides messaging capability and facilitates communication between the modules/applications.
13. Variable types available in Mule ESB.
Flow Variable - that works as instance properties, Session Variable - that acts ike session properties, Record Variable - available only in Batch Job Flows.
14. Features of ESB.
Routing, Message transformation, Message enhancement, protocol transformation, Service mapping, Message processing, Process choreography, Service orchestration, Transaction management, Enterprise integration design patterns, and Security.
15. Explain the Mule message in the context of Mule Flow.
The Mule message is the data that passes through an application via one or more flows. It consists of two main parts: The message header , which contains metadata about the message. The message payload , which contains your business-specific data. A Mule message is, itself, embedded within a Mule...
16. What is the MuleSoft Anypoint platform?
Anypoint Platform is a hybrid integration platform that enables to easily build and rapidly scale an application network of apps, data, and devices through APIs and integrations.
17. I have no experience on Mule ESB, but I have knowledge on it. If interviewer asks scenario based questions what i need to answer please help me.
Thanks for your question. Scenario based questions usually will be comparison based, for example, tibco vs mule or any other integration framework. Also there may questions on mule transactions. Try to understand the question and try to answer on how you would practically approach the scenario. T...
18. How to implement Custom Connectors in Mule ESB?
We may develop a new custom connector project in Mulesoft Any Point studio and it involves the below steps. Set up Connector Project in Anypoint studio, Write Connector Code, Write Connector unit Tests (optional but recommended), Document the Connector for reference, Package the custom Connector.
