Pass MuleSoft-Platform-Architect-I Exam Guide

Understanding Circuit Breaker Policy:

A circuit breaker is a design pattern used to detect failures and prevent an application from continually trying to execute a failing operation. In this case, it will help improve response time and reduce demand on the downstream API.

The specified configuration includes conditions for opening, half-opening, and closing the circuit based on error rates over time:

Circuit Open: Triggered if there are more than 10 errors per minute for three consecutive minutes.

Circuit Half-Open: The circuit transitions to half-open if there is one error per minute.

Circuit Closed: The circuit closes if the error rate is less than one error per minute for five minutes.

Evaluating the Options:

Option A: Creating a custom policy with template expressions could work, but it would require custom development. Since the Anypoint Platform already has a Circuit Breaker policy available, this would be a less efficient and more complex solution.

Option B: Anypoint Monitoring alerts can be used for monitoring the API, but they do not provide circuit-breaking functionality. Additionally, implementing a retry strategy for the half-open state is not sufficient to achieve the required circuit breaker behavior.

Option C (Correct Answer): Adding the Circuit Breaker policy to the API instance on Anypoint Platform allows you to set up circuit-breaking conditions directly. This approach uses the built-in Circuit Breaker policy, where you can configure parameters such as error thresholds and time intervals to match the requirements. This solution is efficient, reliable, and leverages Anypoint’s out-of-the-box capabilities.

Option D: Implementing the strategy within a Mule application with a YAML configuration could be complex and less manageable. Additionally, it does not leverage Anypoint Platform’s built-in Circuit Breaker policy, which is more suited to this scenario.

Conclusion:

Option C is the correct choice, as it leverages Anypoint Platform’s Circuit Breaker policy. This solution allows for configuring thresholds and time intervals as specified, improving response time and reducing demand on the downstream API while utilizing Anypoint's managed policy feature.

Refer to MuleSoft’s documentation on implementing the Circuit Breaker policy in API Manager for detailed configuration guidance.

Explanation

Correct Answer: The test runs immediately after the Mule application has been compiled and packaged

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>> Integration tests are the last layer of tests we need to add to be fully covered.

>> These tests actually run against Mule running with your full configuration in place and are tested from external source as they work in PROD.

>> These tests exercise the application as a whole with actual transports enabled. So, external systems are affected when these tests run.

So, these tests do NOT run immediately after the Mule application has been compiled and packaged.

FYI... Unit Tests are the one that run immediately after the Mule application has been compiled and packaged.

Explanation

Correct Answer: Apply a basic authentication - LDAP policy; the internal Active Directory will be configured as the LDAP source for authenticating users.

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>> IP Whitelisting does NOT fit for this purpose. Moreover, the users workstations may not necessarily have static IPs in the network.

>> OAuth 2.0 enforcement requires a client provider which isn't in the organizations system components.

>> It is not an effective approach to let every user create separate client credentials and configure those for their usage.

The effective way it to apply a basic authentication - LDAP policy and the internal Active Directory will be configured as the LDAP source for authenticating users.

Explanation

Correct Answer: When the API implementation changes the structure of the request or response messages

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>> RAML definition usually needs to be touched only when there are changes in the request/response schemas or in any traits on API.

>> It need not be modified for any internal changes in API implementation like performance tuning, backend system migrations etc..