D. The external API reported an error with the HTTP request that was received from the outbound HTTP Request operation of the Mule application

Answer DescriptionExplanation

Correct choice is: "The external API reported an error with the HTTP request that was received from the outbound HTTP Request operation of the Mule application"

Understanding HTTP 4XX Client Error Response Codes : A 4XX Error is an error that arises in cases where there is a problem with the user’s request, and not with the server.

Such cases usually arise when a user’s access to a webpage is restricted, the user misspells the URL, or when a webpage is nonexistent or removed from the public’s view.

In short, it is an error that occurs because of a mismatch between what a user is trying to access, and its availability to the user — either because the user does not have the right to access it, or because what the user is trying to access simply does not exist. Some of the examples of 4XX errors are

400 Bad Request The server could not understand the request due to invalid syntax. 401 Unauthorized Although the HTTP standard specifies "unauthorized", semantically this response means "unauthenticated". That is, the client must authenticate itself to get the requested response. 403 Forbidden The client does not have access rights to the content; that is, it is unauthorized, so the server is refusing to give the requested resource. Unlike 401, the client's identity is known to the server. 404 Not Found The server can not find the requested resource. In the browser, this means the URL is not recognized. In an API, this can also mean that the endpoint is valid but the resource itself does not exist. Servers may also send this response instead of 403 to hide the existence of a resource from an unauthorized client. This response code is probably the most famous one due to its frequent occurrence on the web. 405 Method Not Allowed The request method is known by the server but has been disabled and cannot be used. For example, an API may forbid DELETE-ing a resource. The two mandatory methods, GET and HEAD, must never be disabled and should not return this error code. 406 Not Acceptable This response is sent when the web server, after performing server-driven content negotiation, doesn't find any content that conforms to the criteria given by the user agent. The external API reported that the API implementation has moved to a different external endpoint cannot be the correct answer as in this situation 301 Moved Permanently The URL of the requested resource has been changed permanently. The new URL is given in the response. ----------------------------------------------------------------------------------------------------------------------------------------------- In Lay man's term the scenario would be: API CLIENT —> MuleSoft API - HTTP request “Hey, API.. process this” —> External API API CLIENT <– MuleSoft API - http response "I'm sorry Client.. something is wrong with that request" <– (4XX) External API

C. Transform by calling any suitable Java class from Dataweave

Answer DescriptionExplanation: Leveraging existing Java-based capabilities for data transformations in a Mule application can enhance efficiency and reuse. Here’s how to integrate Java classes for transformations:
Create Java Classes:
Configure DataWeave to Call Java Methods:
%dw 2.0 import * from my.package.ClassName output application/json --- { transformedData: ClassName::methodName(payload) }
Perform Transformations:
Test Transformations:
This approach allows for seamless integration of existing Java logic into Mule applications, leveraging DataWeave’s power for comprehensive data transformations.

C. API Client > API Interface > API implementation

Answer DescriptionExplanation:

In a typical REST request, the order of interaction is:

API Client: The client initiates the request to access data or functionality exposed by the API. API Interface: This represents the contract or the definition of the API, often specified in OpenAPI or RAML. It defines the endpoints, request/response formats, and other API details. API Implementation: This is the actual backend logic that processes the request and returns the response. It interacts with databases, other services, or performs business logic to fulfill the request.

References:

Understanding REST APIs

API Design and Implementation

A. Use JAXB (XML) and Jackson (JSON) data bindings

D. Create a parent POM of all the required dependencies and reference each in each application's POM.xml file

B. Use the parameter primaryNodeOnly= "false" on the JMS listener with a shared subscription

Answer DescriptionExplanation:

In a clustered Mule runtime environment, when using a JMS listener to consume messages from a queue destination, it is essential to ensure that messages are appropriately received by all nodes in the cluster. The configuration must support high availability and scalability. Here's why option B is correct:

primaryNodeOnly="false": Setting this parameter to "false" ensures that the JMS listener is active on all nodes in the cluster, not just the primary node. This setting allows multiple instances of the JMS listener to run concurrently across different nodes, enabling them to consume messages from the JMS queue.

Shared Subscription: Using a shared subscription means that all nodes will share the consumption of messages from the queue. This approach prevents duplicate message processing, as each message is delivered to only one listener instance within the cluster. This configuration ensures that message processing is balanced across the nodes, improving throughput and reliability.

To configure the JMS listener in Mule, the XML configuration might look something like this:

xml

This setup ensures that all nodes in the cluster are involved in message processing, leveraging the high availability and load balancing capabilities of the cluster.

References

MuleSoft Documentation on JMS Listener

MuleSoft Clustering Guide

A. Each Batch Job uses SEVERAL THREADS for the Batch Steps Each Batch Step instance receives ONE record at a time as the payload, and RECORDS are processed IN PARALLEL within and between the two Batch Steps

B. API Designer

Answer DescriptionExplanation: A MuleSoft developer should use API Designer to create an API specification prior to building the API implementation. API Designer is a component of Anypoint Platform that provides a web-based interface for designing and documenting APIs. It supports API modeling languages such as RAML and OAS, enabling developers to define the structure, resources, and operations of an API before proceeding with implementation. This approach aligns with the design-first methodology, ensuring a well-defined contract for the API.