Mulesoft MCPA-Level-1 Exam Questions

Implement different system APIs named createCustomer, amendCustomer,
retrieveCustomer and suspendCustomer as they are modular and has seperation of concerns

Correct Answer: Implement different system APIs named createCustomer,
amendCustomer, retrieveCustomer and suspendCustomer as they are modular and has
seperation of concerns
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>> It is quite normal to have a single API and different Verb + Resource combinations.
However, this fits well for an Experience API or a Process API but not a best architecture
style for System APIs. So, option with just one customerManagement API is not the best
choice here.
>> The option with APIs in createCustomerInCRMZ format is next close choice w.r.t
modularization and less maintenance but the naming of APIs is directly coupled with the
legacy system. A better foreseen approach would be to name your APIs by abstracting the
backend system names as it allows seamless replacement/migration of any backend
system anytime. So, this is not the correct choice too.
>> createCustomer, amendCustomer, retrieveCustomer and suspendCustomer is the right
approach and is the best fit compared to other options as they are both modular and same
time got the names decoupled from backend system and it has covered all requirements a
System API needs.

Implement required changes to the Process API implementation so that whenever
possible, the Process API's RAML definition remains unchanged

Explanation: Explanation
Correct Answer: Implement required changes to the Process API implementation so that,
whenever possible, the Process API’s RAML definition remains unchanged.
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Key requirement in the question is:
>> Approach that minimizes the impact of this change on API clients
Based on above:
>> Updating the RAML definition would possibly impact the API clients if the changes
require any thing mandatory from client side. So, one should try to avoid doing that until
really necessary.
>> Implementing the changes as a completely different API and then redirectly the clients
with 3xx status code is really upsetting design and heavily impacts the API clients.
>> Organisations and IT cannot simply postpone the changes required until all API
consumers acknowledge they are ready to migrate to a new Process API or API version.
This is unrealistic and not possible.
The best way to handle the changes always is to implement required changes to the API
implementations so that, whenever possible, the API’s RAML definition remains
unchanged.

Explanation:
Understanding API Autodiscovery in MuleSoft:
Effect of Asset Version Update on API Autodiscovery:
Evaluating the Options:

GET, OPTIONS, HEAD

By refining the response definitions by adding the x-ratelimit-* response headers with
description, type, and example

Explanation: Explanation
Correct Answer: By refining the response definitions by adding the x-ratelimit-* response
headers with description, type, and example
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The API policy Is defined In API Manager for a specific API Instance, and then ONLY
applied to the specific API instance

Explanation: Explanation
Correct Answer: The API policy is defined in API Manager for a specific API instance, and
then ONLY applied to the specific API instance.
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>> Once our API specifications are ready and published to Exchange, we need to visit API
Manager and register an API instance for each API.
>> API Manager is the place where management of API aspects takes place like
addressing NFRs by enforcing policies on them.
>> We can create multiple instances for a same API and manage them differently for
different purposes.
>> One instance can have a set of API policies applied and another instance of same API
can have different set of policies applied for some other purpose.
>> These APIs and their instances are defined PER environment basis. So, one need to
manage them seperately in each environment.
>> We can ensure that same configuration of API instances (SLAs, Policies etc..) gets
promoted when promoting to higher environments using platform feature. But this is
optional only. Still one can change them per environment basis if they have to.
>> Runtime Manager is the place to manage API Implementations and their Mule Runtimes
but NOT APIs itself. Though API policies gets executed in Mule Runtimes, We CANNOT
enforce API policies in Runtime Manager. We would need to do that via API Manager only
for a cherry picked instance in an environment.
So, based on these facts, right statement in the given choices is - "The API policy is
defined in API Manager for a specific API instance, and then ONLY applied to the specific
API instance".
Reference: https://docs.mulesoft.com/api-manager/2.x/latest-overview-concept

Increase the number of CloudHub workers

Explanation: Explanation
Correct Answer: Increase the size of the CloudHub worker(s)
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The key details that we can take out from the given scenario are:
>> API implementation uses a database bulk insert command to submit all the purchase
data to a database
>> JDBC driver processes the data into a set of several temporary disk files on the
CloudHub worker
>> Sometimes a request fails and the logs show a message indicating an out-of-file-space
message
Based on above details:
>> Both auto-scaling options does NOT help because we cannot set auto-scaling rules
based on error messages. Auto-scaling rules are kicked-off based on CPU/Memory usages
and not due to some given error or disk space issues.
>> Increasing the number of CloudHub workers also does NOT help here because the
reason for the failure is not due to performance aspects w.r.t CPU or Memory. It is due to
disk-space.
>> Moreover, the API is doing bulk insert to submit the received batch data. Which means,
all data is handled by ONE worker only at a time. So, the disk space issue should be
tackled on "per worker" basis. Having multiple workers does not help as the batch may still
fail on any worker when disk is out of space on that particular worker.
Therefore, the right way to deal this issue and resolve this is to increase the vCore size of
the worker so that a new worker with more disk space will be provisioned.

Explanation: Explanation
Correct Answer: In parallel, invoke the system API deployed to the primary environment
and the system API deployed to the DR environment, and ONLY use the first response.
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>> The API requirement in the given scenario is to respond in least possible time.
>> The option that is suggesting to first try the API in primary environment and then
fallback to API in DR environment would result in successful response but NOT in least
possible time. So, this is NOT a right choice of implementation for given requirement.
>> Another option that is suggesting to ONLY invoke API in primary environment and to
add timeout and retries may also result in successful response upon retries but NOT in
least possible time. So, this is also NOT a right choice of implementation for given
requirement.
>> One more option that is suggesting to invoke API in primary environment and API in DR
environment in parallel using Scatter-Gather would result in wrong API response as it
would return merged results and moreover, Scatter-Gather does things in parallel which is
true but still completes its scope only on finishing all routes inside it. So again, NOT a right
choice of implementation for given requirement
The Correct choice is to invoke the API in primary environment and the API in DR
environment parallelly, and using ONLY the first response received from one of them