Free Practice Questions for Salesforce MuleSoft-Integration-Architect-I Exam

Explanation

● Option A says "Perform EACH DB insert in a SEPARATE DB transaction". In this case if first DB insert is successful and second one fails then first insert won't be rolled back causing inconsistency. This option is ruled out.

● Option D says Perform BOTH DB inserts in ONE DB transaction.

Rule of thumb is when one or more DB connections are required we must use XA transaction as local transactions support only one resource. So this option is also ruled out.

● Option B acknowledges the before DB processing, so message is removed from the queue. In case of system failure at later point, message can't be retrieved.

● Option C is Valid: Though it says "do not ack JMS message", message will be auto acknowledged at the end of transaction. Here is how we can ensure all components are part of XA transaction: https://docs.mulesoft.com/jms-connector/1.7/jms-transactions

Additional Information about transactions:

● XA Transactions - You can use an XA transaction to group together a series of operations from multiple transactional resources, such as JMS, VM or JDBC resources, into a single, very reliable, global transaction.

● The XA (eXtended Architecture) standard is an X/Open group standard which specifies the interface between a global transaction manager and local transactional resource managers.

The XA protocol defines a 2-phase commit protocol which can be used to more reliably coordinate and sequence a series of "all or nothing" operations across multiple servers, even servers of different types

● Use JMS ack if

– Acknowledgment should occur eventually, perhaps asynchronously

– The performance of the message receipt is paramount

– The message processing is idempotent

– For the choreography portion of the SAGA pattern

● Use JMS transactions

– For all other times in the integration you want to perform an atomic unit of work

– When the unit of work comprises more than the receipt of a single message

– To simply and unify the programming model (begin/commit/rollback)

A MuleSoft developer can use Anypoint Studio to implement an API as a Mule application, run the application locally, and execute unit tests against the running application. Anypoint Studio is an integrated development environment (IDE) for designing, building, testing, and deploying Mule applications. It provides tools for local development and testing, including MUnit for creating and running unit tests, making it a comprehensive solution for developing MuleSoft applications.

Explanation

Correct answer is For Each scope in the parent flow On Error Continue error handler in the child flow. You can extract below set of requirements from the question a) Records should be sent to downstream system in the same order that it was received in the array b) Any validation or communication failures should not prevent further processing of the remaining records First requirement can be met using For Each scope in the parent flow and second requirement can be met using On Error Continue scope in child flow so that error will be suppressed.

Explanation

* XA transaction add tremendous latency so "Reduce Latency" is incorrect option XA transactions define "All or No" commit protocol.

* Each local XA resource manager supports the A.C.I.D properties (Atomicity, Consistency, Isolation, and Durability).

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So correct choice is "Ensure consistency"

Explanation

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.

When using a non-persistent object store in MuleSoft, the state data is stored in memory rather than on disk. This means that if a server crashes, all data stored in the non-persistent object store will be lost because it does not survive a server restart or crash. Non-persistent object stores are typically used for temporary data that does not need to be retained across application restarts. Therefore, in an environment where an API is maintaining its state using a non-persistent object store, a server crash will result in the loss of that state data.

MuleSoft Documentation on Object Store

Explanation

Correct answer is Perform all communication involving service S synchronously from within the For Each scope, so objects in RESP are in the exact same order as request objects in REQU Explanation : Using Anypoint MQ, you can create two types of queues: Standard queue These queues don’t guarantee a specific message order. Standard queues are the best fit for applications in which messages must be delivered quickly. FIFO (first in, first out) queue These queues ensure that your messages arrive in order. FIFO queues are the best fit for applications requiring strict message ordering and exactly-once delivery, but in which message delivery speed is of less importance Use of FIFO queue is no where in the option and also it decreased throughput. Similarly persistent object store is not the preferred solution approach when you maximizing message throughput. This rules out one of the options. Scatter Gather does not support ObjectStore. This rules out one of the options. Standard Anypoint MQ queues don’t guarantee a specific message order hence using another for each block to collect response wont work as requirement here is to ensure the order. Hence considering all the above factors the feasible approach is Perform all communication involving service S synchronously from within the For Each scope, so objects in RESP are in the exact same order as request objects in REQU

* "100% increase in the throughput of the API" might look correct, as the number of requests processed per second might increase, but is it guaranteed to increase by 100%? Using 4 nodes will definitely increase throughput of system. But it is cant be precisely said if there would be 100% increase in throughput as it depends on many other factors. Also it is nowhere mentioned in the description that all nodes have same CPU/memory assigned. The question is about the guaranteed behavior * Increasing number of nodes will have no impact on response time as we are scaling application horizontally and not vertically. Similarly there is no change in JVM heap memory usage. * So Correct answer is 50% reduction in the number of requests being received by each node This is because of the two reasons. 1) API is mentioned as stateless 2) Load Balancer is used

When a Mule application using VM (Virtual Machine) queues is deployed to a customer-hosted cluster or multiple CloudHub workers, the messages are consumed by the Mule engine in a non-deterministic way. Here’s an in-depth explanation:

VM Queues Overview:

VM queues in Mule applications are used for intra-application communication, allowing different flows within the same application to exchange messages.

Deployment in Clusters or Multiple Workers:

Customer-Hosted Cluster: In a customer-hosted cluster, multiple Mule runtime instances work together to process messages. Each instance can pick up messages from the VM queue.

CloudHub Workers: When deployed on CloudHub, multiple worker instances can run the same Mule application, and each worker can access the VM queue.

Non-Deterministic Message Consumption:

Load Distribution: Messages are distributed among the available nodes or workers based on their availability. This means any node or worker that is ready to process a message can pick it up from the queue.

No Guaranteed Order: Because any available node or worker can consume messages, the order in which messages are processed is not guaranteed, making the consumption non-deterministic.

Parallel Processing: This approach allows for parallel processing of messages, which improves the scalability and throughput of the application.

Advantages:

Scalability: By allowing multiple nodes or workers to process messages, the system can handle increased load more effectively.

Fault Tolerance: If one node or worker fails, other nodes/workers can continue processing messages from the VM queue, providing higher availability.

Considerations:

Idempotency: Ensure that the processing logic is idempotent, meaning that processing the same message more than once does not produce different outcomes. This is crucial in a non-deterministic consumption environment to avoid issues with data consistency.

Transaction Management: Proper transaction management should be in place to handle scenarios where a message might need to be reprocessed due to errors.

MuleSoft Documentation on VM Connector

MuleSoft Documentation on High Availability Clustering

MuleSoft Documentation on Deploying to CloudHub

In a microservices architecture, a service mesh manages the communication between microservices. This involves handling service discovery, load balancing, failure recovery, metrics, and monitoring. Service meshes also provide more complex operational requirements like A/B testing, canary releases, rate limiting, access control, and end-to-end authentication. By abstracting these functionalities away from individual microservices, a service mesh allows developers to focus on business logic while ensuring reliable and secure inter-service communication.