MCD-Level-2 MuleSoft Certified Developer - Level 2 (Mule 4) Questions and Answers

The validate-customer flow uses an until-successful scope to validate each field of the customer data. The until-successful scope executes its processors until they succeed or exhausts the maximum number of retries. If any processor fails, it raises an error and stops executing the remaining processors. Therefore, if only the email address is invalid, a VALIDATION.INVALID_EMAIL error is raised and the validation of appointment date and customer name is skipped. References: https://docs.mulesoft.com/mule-runtime/4.3/until-successful-scope

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: https://docs.mulesoft.com/object-store/osv2-faq#how-does-the-time-to-live-work

A cipher suite is a set of cryptographic algorithms that are used to secure the communication between a client and a server. A cipher suite consists of four components: a key exchange algorithm, an authentication algorithm, an encryption algorithm, and a message authentication code (MAC) algorithm. During the cipher suite exchange, the client and the server agree on which encryption algorithm to use for encrypting and decrypting the data. References: https://docs.mulesoft.com/mule-runtime/4.3/tls-configuration#cipher-suites

The correct sequence of activities that takes place during the Maven build and deployment is validate, initialize, compile, test package, verify, install, deploy. These are Maven lifecycle phases that define a sequence of goals to execute during a build process. Each phase represents a stage in the build lifecycle and can have zero or more goals bound to it. References: https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html

When implementing a synchronous API where the event source is an HTTP Listener, Mule automatically propagates some message attributes between flows via outbound and inbound properties. One of these attributes is correlation ID, which is returned to the caller in the response header by default as MULE_CORRELATION_ID. References: https://docs.mulesoft.com/mule-runtime/4.3/about-mule-message#message-attributes

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: https://docs.mulesoft.com/mule-sdk/1.1/xml-sdk#testing

To implement a readiness endpoint to monitor all system APIs, the developer should create a dedicated endpoint that responds with the API status and reachability of the underlying systems. This way, the DevOps team can check if the system API is ready to receive requests and if it can communicate with its backend systems without errors. References: https://docs.mulesoft.com/mule-runtime/4.3/deployment-strategies#readiness-probes

When the HTTP Request operation raises an HTTP CONNECTIVITY error, it triggers an on-error-continue handler that sets a payload with ‘Error in processing your request’. Since no status code is explicitly set in this handler, it defaults to 500 (INTERNAL SERVER ERROR). Therefore, the web client receives an HTTP response with status code 500 and body ‘Error in processing your request’. References: https://docs.mulesoft.com/mule-runtime/4.3/error-handling#on-error-continue

To package a custom policy using the HTTP Policy Transform Extension, the developer needs to create an XML template file and a YAML configuration file. The XML template file defines the policy logic using Mule components and placeholders for user-defined properties. The YAML configuration file defines the metadata of the policy, such as its name, description, category, parameters, and dependencies. References: https://docs.mulesoft.com/api-manager/2.x/http-policy-transform#packaging-the-policy

To create a new project that selects the correct API version and scaffolds the flows from the API specification, the developer should import a published API. This option allows importing an API specification that has been published to Anypoint Exchange or Design Center, and selecting a specific version of that API specification. The developer can also choose to scaffold flows based on that API specification. References: https://docs.mulesoft.com/apikit/4.x/apikit-4-new-project-task

To temporarily persist large files over 10MB between flow executions, and routinely query whether the file data exists on separate executions, the developer should store the contents of the file on separate storage, and store the key and location of the file object using Object Store v2. This way, the developer can avoid storing large files in memory or exceeding the size limit of Object Store v2 (10MB per object). The developer can also use Object Store v2 operations to query, retrieve, or delete the file object by its key. References: https://docs.mulesoft.com/object-store/osv2-faq#can-i-store-files-in-object-store-v2

To use API autodiscovery to access and enforce policies for a RESTful implementation, flowRef must be set to the name of the flow that has HTTP listener to receive all incoming RESTful operation requests. This way, API autodiscovery can identify the API implementation and associate it with the corresponding API specification and policies in API Manager. The flow that has HTTP listener is usually the main flow that contains the APIKit Router. References: https://docs.mulesoft.com/api-manager/2.x/api-auto-discovery-new-concept#flowref

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: https://docs.mulesoft.com/mule-runtime/4.3/mmp-concept#add-a-maven-dependency-to-the-pom-file

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: https://docs.mulesoft.com/munit/2.3/assert-equals-processor

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: https://docs.mulesoft.com/mule-sdk/1.1/xml-sdk#operations