MuleSoft-Platform-Architect-I Exam Dumps : Salesforce Certified MuleSoft Platform Architect (Mule-Arch-201)

Explanation

Correct Answer: Set a timeout of 100ms; that leaves 400ms for other two downstream APIs to complete

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Key details to take from the given scenario:

>> Upstream API's designed SLA is 500ms (median). Lets ignore maximum SLA response times.

>> This API calls 3 downstream APIs sequentially and all these are of similar complexity.

>> The first downstream API is offering median SLA of 100ms, 80th percentile: 500ms; 95th percentile: 1000ms.

Based on the above details:

>> We can rule out the option which is suggesting to set 50ms timeout. Because, if the median SLA itself being offered is 100ms then most of the calls are going to timeout and time gets wasted in retried them and eventually gets exhausted with all retries. Even if some retries gets successful, the remaining time wont leave enough room for 2nd and 3rd downstream APIs to respond within time.

>> The option suggesting to NOT set a timeout as the invocation of this API is mandatory and so we must wait until it responds is silly. As not setting time out would go against the good implementation pattern and moreover if the first API is not responding within its offered median SLA 100ms then most probably it would either respond in 500ms (80th percentile) or 1000ms (95th percentile). In BOTH cases, getting a successful response from 1st downstream API does NO GOOD because already by this time the Upstream API SLA of 500 ms is breached. There is no time left to call 2nd and 3rd downstream APIs.

>> It is NOT true that no timeout is possible to meet the upstream APIs desired SLA.

As 1st downstream API is offering its median SLA of 100ms, it means MOST of the time we would get the responses within that time. So, setting a timeout of 100ms would be ideal for MOST calls as it leaves enough room of 400ms for remaining 2 downstream API calls.

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.

Understanding the Need for Cross-API Monitoring:

The Center for Enablement (C4E) needs to investigate potential technical issues across multiple APIs in the application network that may be causing customers to abandon their carts.

This requires a solution that allows viewing metrics across several APIs in real-time to identify any performance issues or bottlenecks.

Evaluating Anypoint Platform Features:

Built-in Dashboards: Anypoint Platform provides built-in dashboards in Anypoint Monitoring, allowing teams to view metrics from multiple APIs in a single interface. This feature is designed to monitor API performance, latency, errors, and throughput, and is ideal for tracking performance across all layers of the application network.

Custom Dashboards: While custom dashboards allow for more tailored views, the built-in dashboards already aggregate metrics for multiple APIs, making it unnecessary to build a custom solution for this scenario.

Functional Monitoring: This feature is used to set up tests to monitor specific API functionality and uptime but is not suited for tracking metrics across multiple APIs in real-time.

API Manager: API Manager primarily focuses on managing API policies, contracts, and access control rather than providing detailed, real-time metrics across the entire application network.

Conclusion:

Option B (Built-in dashboards) is the best choice because it provides a comprehensive view of metrics from all APIs involved, enabling the C4E team to quickly identify any issues that may be contributing to abandoned shopping carts.

Refer to MuleSoft’s documentation on Anypoint Monitoring and built-in dashboards for more details on configuring and using these dashboards effectively.