Correct answer is Create a mocking service that replicates the backend system's production performance characteristics. Then configure the API implementation to use the mocking service and conduct the performance tests
* MUnit is for only Unit and integration testing for APIs and Mule apps. Not for performance Testing, even if it has the ability to Mock the backend.
* Bypassing the backend invocation defeats the whole purpose of performance testing. Hence it is not a valid answer.
* Scaled down performance tests cant be relied upon as performance of API's is not linear against load.

* If you need to scale a JMS provider/ message broker, - add nodes to scale it horizontally or - add memory to scale it vertically
* Cons of adding another JMS provider/ message broker: - adds cost. - adds complexity to use two JMS brokers - adds Operational overhead if we use two brokers, say, ActiveMQ and IBM MQ
* So Two options that mention to use two brokers are not best choice. * It's mentioned that "The Fulfillment microservice consumes Order messages, fulfills the order described therein, and then publishes an OrderFulfilled message. Each OrderFulfilled message can be consumed by any interested Mule application."
- When you publish a message on a topic, it goes to all the subscribers who are interested - so zero to many subscribers will receive a copy of the message.
- When you send a message on a queue, it will be received by exactly one consumer. * As we need multiple consumers to consume the message below option is not valid choice: "Order messages are sent to an Anypoint MQ exchange. OrderFulfilled messages are sent to an Anypoint MQ queue.
Both microservices interact with Anypoint MQ as the message broker, which must therefore scale to support the load of both microservices" * Order messages are only consumed by one Mule application, the Fulfillment microservice, so we will publish it on queue and OrderFulfilled message can be consumed by any interested Mule application so it need to be published on Topic using same broker.
* Correct:

* Mule Domain Project is ONLY available for customer-hosted Mule runtimes, but not for Anypoint Runtime Fabric
* Mule domain project is available for Hybrid and Private Cloud (PCE). Rest all provide application isolation and can't support domain project.
What is Mule Domain Project?
* A Mule Domain Project is implemented to configure the resources that are shared among different projects. These resources can be used by all the projects associated with this domain. Mule applications can be associated with only one domain, but a domain can be associated with multiple projects. Shared resources allow multiple development teams to work in parallel using the same set of reusable connectors. Defining these connectors as shared resources at the domain level allows the team to: - Expose multiple services within the domain through the same port. - Share the connection to persistent storage. - Share services between apps through a well-defined interface. - Ensure consistency between apps upon any changes because the configuration is only set in one place.
* Use domains Project to share the same host and port among multiple projects. You can declare the http connector within a domain project and associate the domain project with other projects. Doing this also allows to control thread settings, keystore configurations, time outs for all the requests made within multiple applications. You may think that one can also achieve this by duplicating the http connector configuration across all the applications. But, doing this may pose a nightmare if you have to make a change and redeploy all the applications.
* If you use connector configuration in the domain and let all the applications use the new domain instead of a default domain, you will maintain only one copy of the http connector configuration. Any changes will require only the domain to the redeployed instead of all the applications.
You can start using domains in only three steps:
1) Create a Mule Domain project
2) Create the global connector configurations which needs to be shared across the applications inside the Mule Domain project
3) Modify the value of domain in mule-deploy.properties file of the applications

* Option B shouldn't be used unless extremely needed, if RAML is changed, client needs to accommodate changes. Question is about minimizing impact on Client. So this is not a valid choice.
* Option C isn't valid as Business can't stop for consumers acknowledgment.
* Option D again needs Client to accommodate changes and isn't viable option.
* Best choice is A where RAML definition isn't changed and underlined functionality is changed without any dependency on client and without impacting client.