MuleSoft MCD-Level-2 MuleSoft Certified Developer - Level 2 (Mule 4) Exam Practice Test

To ensure idempotent behavior within a Mule flow that contains a subflow with a Scatter-Gather scope, the developer should ensure an error-handling flow performs corrective actions to roll back all changes if any leg of the Scatter-Gather fails. Idempotency means that multiple identical requests have the same effect as a single request. Therefore, if one of the HTTP requests inside the Scatter-Gather fails, the error-handling flow should undo any changes made by other successful requests to ensure consistency and avoid partial updates. References:

The result of the flow is nullPayload if processing between os:store and os:retrieve takes 10 seconds. This is because the entry TTL of the object store is one second, which means that any stored value expires after one second and is removed from the object store. The expiration interval of 30 seconds only determines how often the object store checks for expired values, but it does not affect the TTL. Therefore, when os:retrieve tries to get the value after 10 seconds, it returns nullPayload because the value has already expired and been removed. References:

To reuse Mule Maven plugin configuration across multiple individual Mule applications, the developer should use a parent pom.xml file. A parent pom.xml file defines common configuration for one or more child projects that inherit from it. The developer can specify common properties and dependencies for all child projects in the parent pom.xml file, such as Mule Maven plugin configuration, and then reference them in each child project’s pom.xml file using placeholders. References:

When an HTTP request is received and the HTTP Caching policy is applied first, it checks if there is a cached response for that request in Object Store. If there is a cache hit, meaning that a valid cached response exists, then only the HTTP Caching policy is evaluated and the cached response is returned to the caller without invoking the OAuth policy or the API implementation. If there is a cache miss, meaning that no valid cached response exists, then both the HTTP Caching policy and the OAuth policy are evaluated before invoking the API implementation. References:

To test that the payment API is working in production, the developer should create a health check endpoint that listens on a separate port and uses a separate HTTP Listener configuration from the API. This way, the developer can isolate the health check endpoint from the API traffic and avoid affecting the performance or availability of the API. The health check endpoint should return a simple response that indicates the status of the API, such as OK or ERROR. References:

To include a common application as a reusable module in all API implementations, the developer should add a Maven dependency in the POM file with jar as . This way, the developer can reuse Mule code from another application by packaging it as a JAR file and adding it as a dependency in the POM file of the API implementation. The classifier element specifies that it is a JAR file. References:

To propagate the order ID as the correlation ID across each message using Anypoint MQ, the developer should wrap all Anypoint MQ Publish operations within a With CorrelationID scope from the Tracing module, setting the correlation ID to the order ID. The With CorrelationID scope allows setting a custom correlation ID for any event that occurs within it. The Tracing module also enables distributed tracing across different Mule applications and services using Anypoint Monitoring. References:

Based on the code snippet and MUnit test case below, when the MUnit test case is executed, the expected result is that the test case fails with an assertion error. This is because the assert-equals processor compares two values for equality, and fails if they are not equal. In this case, the expected value is ‘Hello World’, but the actual value returned by the implementation flow is ‘Hello Mule’. Therefore, the assertion fails and an error is thrown. References:

When using XML SDK for creating custom message processors, all operations are public by default and can be used by any Mule application that imports them. There is no way to make an operation private or protected in XML SDK. References:

Based on the configuration below, when a HTTP request arrives at the Mule application’s endpoint, the execution order will be A1, B1, F1, B2, A2. This is because policies are executed before and after the API implementation flow according to their order attribute. Policy A has order 1, which means it is executed first before Policy B, which has order 2. The flow is executed after both policies are executed before the flow. Then, Policy B is executed after the flow before Policy A is executed after the flow. References:

To manually approve or reject request access when registering a client application with an existing API instance or API Group instance, it is required to configure the SLA tier for the application and have one of the following roles or permissions: Organization Administrator, API Manager Environment Administrator, or Manage Contracts permission. These roles or permissions allow managing client applications and contracts in API Manager. References:

To develop an API that retrieves data from a hospital system using reusable Java libraries, the developer should install libraries in a local repository and refer to it in the pom.xml file. This way, the developer can use Maven to manage dependencies and invoke Java code from Mule applications using Java Module operations. References:

The result of accessing route C failure is Error,errorMessage,payload.failures[‘2’]. This is because a scatter-gather router returns an aggregated message that contains an array of results from each route and an array of failures from each route. The failures array contains error objects with information about each failed route execution. To access route C failure, which is the third route (index 2), the developer needs to use Error.errorMessage.payload.failures[‘2’] expression. References:

The Cache scope supports time to live (TTL) as a cache invalidation strategy without having to write any additional code. TTL specifies how long the cached response is valid before it expires and needs to be refreshed. The Cache scope also supports custom invalidation strategies using MEL or DataWeave expressions. References:

To validate the data before posting to the target system, the developer should add the JSON module dependency and add the validate-schema operation in the flow, configured to reference the schema. The JSON module provides a validate-schema operation that validates a JSON payload against a JSON schema and throws an error if the payload is invalid. References:

To unit test modules created with XML SDK, the developer needs to use the MUnit Extensions Maven plugin. This plugin allows testing XML SDK modules using MUnit by adding a dependency to the module under test and using a custom processor tag to invoke it. References:

To configure the Maven Resources plugin to exclude parsing binary files in the project’s src/main/resources/certs directory, option C should be used. This option specifies that any files with .cer or .jks extensions under the certs directory should be excluded from filtering. Filtering is a process of replacing placeholders with actual values in resource files during the build process. Binary files should not be filtered because they may become corrupted or unusable. References:

To invoke multiple HTTP APIs in parallel and roll back failed requests in sequence, the developer should use a Scatter-Gather router as a central Saga orchestrator for all API requests with compensating actions for failing routes. A Scatter-Gather router executes multiple routes concurrently and aggregates the results. A Saga orchestrator coordinates a series of actions across different services and handles failures by executing compensating actions. Therefore, using a Scatter-Gather router as a Saga orchestrator allows invoking multiple HTTP APIs in parallel and rolling back any failed requests in sequence. References: