MCD-Level-1 MuleSoft Certified Developer - Level 1 (Mule 4) Questions and Answers

MuleSoft Documentation Reference : https://docs.mulesoft.com/db-connector/1.9/database-connector-select

Correct answer is Modify the API implementation to use auto-discovery to register with API Manager

API Autodiscovery

Configuring autodiscovery allows a deployed Mule runtime engine (Mule) application to connect with API Manager to download and manage policies and to generate analytics data. Additionally, with autodiscovery, you can configure your Mule applications to act as their own API proxy.

When autodiscovery is correctly configured in your Mule application, you can say that your application’s API is tracked by (green dot) or paired to API Manager. You can associate an API in a Mule setup with only one autodiscovery instance at a given time.

MuleSoft Doc Ref : https://docs.mulesoft.com/api-manager/2.x/api-auto-discovery-new-concept

Organization Administrators can approve/revoke/delete SLA tier access requests via API Manager only

Correct answer is A global element

When we create a configuration file , that file needs to added as Global Configuration file in Global element. A global element is a reusable object containing parameters that any number of elements in a flow can share. You reference a global element from Anypoint Connectors or components in your Mule application

An object store is a facility for storing objects in or across Mule applications. Mule runtime engine (Mule) uses object stores to persist data for eventual retrieval. Internally, Mule uses object stores in various filters, routers, and other message processors that need to store states between messages.

Object stores are available in all deployment targets. If you deploy your application to CloudHub, you can also use Object Store V2.

Correct answer is Key/value pair in Object store

MuleSoft Documentation reference : https://docs.mulesoft.com/mule-runtime/4.3/mule-object-stores#use-cases

Correct answer is 8 as events are processed in parallel in case of scatter gather router

MuleSoft Doc Ref : https://docs.mulesoft.com/api-manager/2.x/policy-mule3-tutorial-manage-an-api#to-add-the-tier

Steps to create SLA Tier are as follows:

1) In API Manager, in API Administration, click a version.

2) Check that the API supports resource-level policies: On the API version details page, in Status, click Configure Endpoint, and check that Type is RAML.

3) Choose the SLA Tiers, and click Add SLA Tier. Set up limit on SLA tier

Mule applications can be scaled vertically by changing worker size. Mule applications can be scaled horizontally by adding more workers.

The HTTP 415 Unsupported Media Type client error response code indicates that the server refuses to accept the request because the payload format is in an unsupported format. The format problem might be due to the request's indicated Content-Type or Content-Encoding , or as a result of inspecting the data directly. In this case as per RAML specification data is expected in application/json and in request Content-Type is set as "text/plain" which is incorrect. Hence solution is set the request Content-Type header to application/json

https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/415

This helps CloudHub to dynamically allocates a port at deployment time.

MuleSoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.3/deploy-to-cloudhub#prerequisites

Correct answer is API manager

APIKIt Creates a separate flow for each HTTP method. Hence 4 private flows would be generated.

MuleSoft Documentation Referrence : https://docs.mulesoft.com/mule-runtime/4.3/build-application-from-api

Exchange is the odd man out here. Rest all are type of asset

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* To use custom modules, you need to import the module or functions you want to use by adding the import directive to the head of your DataWeave script, for example:

1) Does not identify any functions to import from the String module:

import dw::core::Strings

2) To identify a specific function to import from the String module:

import camelize, capitalize from dw::core::Strings

3) To import all functions from the String module:

import * from dw::core::Strings

The way you import a module impacts the way you need to call its functions from a DataWeave script. If the directive does not list specific functions to import or use * from to import all functions from a function module, you need to specify the module when you call the function from your script.

* In given scenario, it's mentioned to import all of the WebStore.dwl

So correct answer is:

In case of an error , batch job completes in flight steps and stops further processing.

MuleSoft Doc Ref : Handling Errors During Batch Job | MuleSoft Documentation

The default is all processing will stop but we can change it by Max Failed Record field.

General -> Max Failed Records: Mule has three options for handling a record-level error: Finish processing, Continue processing and Continue processing until the batch job accumulates a maximum number of failed records. This behavior can be controlled by Max Failed Records.

The default value is Zero which corresponds to Finish processing.

The value -1, corresponds to Continue processing.

The value +ve integer, corresponds to Continue processing until the batch job accumulates a maximum number of failed records

API Exchange creates REST conenctor automtaically once API is published. Hence correct answer is Publish the API specification to Any point Exchange

Correct answer is as below. In this case address will be stored in a variable. Hence payload will not be overwritten and will contain order details

{

orderkey: "payload.order",

addresskey: "vars.address"

}

Application properties can be defined in .yaml or in .properties file.

MuleSoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.3/configuring-properties#supported_files

Database always return rows as an array.

Array is the correct answer

In this case as outbound call is made using HTTP: POST /child , all attributes will be replaced by this invocation. Hence query parameter will not be accessible at logger. Hence correct answer is option 2

client-id-required enforces clients to add client_id and client_secret.

Please refer to below steps.

• Add a section called traits: at the root level to define query parameters:
• traits:
• - client-id-required:
• queryParameters:
• client_id:
• type: string
• client_secret:
• type: string
• 2) Reference the trait in each of the methods to specify that each of the methods require these query parameters. After each method in the RAML file, add is: [client-id-required]. For example:
• /users:
• get:
• is: [client-id-required]
• description: Gets a list of JSONPlaceholder users.

In this case both the flows can start without any error and requests can be received on both ports. Flow names httpListener1 can call other flow using HTTP request without any issues.

Hence correct answer is

The mule application start successfully

Web client requests can  be received at URI on port 2222 and on port 3333.

Lets check why other options are incorrect

1) The mule application fails to start. There is URL path conflict because both HTTP Listeners are configured with same path  ---- This is incorrect as port value is different in both listeners

2) The mule application start successfully. Web client requests can only be received at URI on port 2222 but not on port 3333  --- This is incorrect as there is no reason for not receiving requests on port 3333

3) The mule application fails to start because of the port binding conflict as HTTP request also use same port i.e. 3333 --- Port binding conflict will not happen in this case. It would have if both listener configurations would have been on same port . But that is not the case here.

Mule Ref Doc : HTTP Listener Reference - Mule 4 | MuleSoft Documentation

Correct answer is Add required headers to RAML specification and redeploy new API proxy

MuleSoft Doc Ref : https://docs.mulesoft.com/api-manager/2.x/tutorial-manage-an-api

Steps are as below :

Add the Required RAML Snippet

SLA-based rate limiting requires adding a RAML or OAS snippet to your API. This procedure demonstrates adding a RAML snippet.

Specify the client ID and secret as query parameters.

Add a section called traits: at the RAML root level to define query parameters:

traits:

- client-id-required:

queryParameters:

client_id:

type: string

client_secret:

type: string

Add the client-id-required trait to every method that requires these query parameters:

/users:

get:

is: [client-id-required]

description: Gets a list of JSONPlaceholder users.

Step 2 : Add the SLA Tier in API Manager

Step 3 : Apply the policy and redeploy

The flow can be described as below. 1) First HTTP POST requets is made in which paylaod is set to 1 and it gets returned to our mail flow. 2) Second call is initiated for JMS Publish Consume JMS: num1 which add 1 to the payload which makes it as 2. Note that pubih consume is a synchronous operation. Hence paylaod is returned to main flow. 3) Third call is initiated for JMS Publish JMS: num2 which add 1 to the payload . Note that pubih is asynchronous operation. Hence paylaod is never returned to main flow. So payload in main flow is still 2. 4) Finally Set Payload increments payload by 1 making payload as 3 which is returned by the flow. Hence option 3 is the correct answer.

APIKIt Creates a separate flow for each HTTP method

* Batch scope has filter criteria which says paylod mod 2 = 0 whch means only 2, 4 and 6 will be in batch scope.

* So payload for each of these will be incremented by 10.

* Aggregator has batch size defined as 2. So it will process in batch of two records.

* Hence option 3 is correct answer.

[20,40]

[60]

Behavior with aggregator configured with fixed size

In this scenario, the batch step sends the processed records to an aggregator, which starts processing the records and buffering them until the configured aggregator’s size is reached. After that, the aggregator sends the aggregated records to the stepping queue.

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The batch job builds record blocks of the configured block size and sends them to their corresponding batch step for processing. Each batch step receives one or more record blocks and starts processing them in parallel. After the batch step processes a record, the batch step sends the record to the aggregator for further processing. The aggregator continues processing records until the number of aggregated records reaches the configured aggregator’s size.

https://docs.mulesoft.com/mule-runtime/4.3/batch-processing-concept

Correct Answer: Response body: "Error" Default response status code: 200.

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1) Payload is successfully set to “Success – Started Flow”

2) When HTTP Request throws an error, execution halts

#[error.description] = “ABC"

#[error.errorType] = "XYZ"

3) The On Error Continue scope handles the error. When On Error Continue scope is invoked, all the processors in error block are executed and success response is sent back to the client with payload which is set in error flow. In this case payload is set to "Error" value in error block.

4) “Error” is returned to the requestor in the body of the HTTP request with HTTP Status Code: 200 as On error continue always sends success error code.

Reference Diagram:

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Correct answer is Request access to the API in Anypoint Exchange. This way we can get clientId and Client secret which we can use to access the API

Correct answer is Products

Modern API has three features 1) Treated as products for easy consumption 2) Discoverable and accessible through self-service 3) Easily managed for security , scalability and performance

Correct answer is Specify throttling , security and other policies

MuleSoft Doc Ref : https://docs.mulesoft.com/api-manager/2.x/api-gateway-capabilities-mule4

API Gateway is responsible for below functions.

1) Determine which traffic is authorized

2) Meter the traffic

3) Logs transaction

4) Apply throttling and other policies (Not specifying. These are specified in API Manager)

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Option 3 is the only corect answer as it concatenates payload with String.

Below option wont work.

#["The payload is " ++ payload]

Concatenation function expects both arguments to be string. As the question says payload is json object , this will throw error while running it. You can try this in Anypoint Studio and you will get the same result which I mentioned.

hence correct answer is

The payload is: #[payload]

Correct answer is Not needed as dw::core module is included by default. We don't need to include it explicitly

The First Successful router iterates through a list of configured processing routes until one of the routes executes successfully. This is sequential execution. In all other options mentioned in the question ,we can achieve parallel execution.

This is a trcik question. On complete phase pyalod consists of summary of records processed which gives insight on which records failed or passed. Hence option 4 is correct answer

MuleSoft Documentation Reference : https://docs.mulesoft.com/mule-runtime/4.3/batch-processing-concept#on-complete

Paths

The path of an HTTP listener can be static, which requires exact matches, or feature placeholders. Placeholders can be wildcards (*), which match against anything they are compared to, or parameters ({param}), which not only match against anything but also capture those values on a URI parameters map.

Take the following example paths for three listeners using a configuration that establishes api/v1 as the base path:

account/mulesoft/main-contact: only match the exact path request http://awesome-company.com/api/v1/account/mulesoft/main-contact

account/{accountId}/main-contact: matches all path requests structured similarly, such as http://awesome-company.com/api/v1/account/salesforce/main-contact , and save salesforce as the value of accountId.

account/{accountId}/*: matches all path requests different from main-contact, such as http://awesome-company.com/api/v1/account/mulesoft/users , and save mulesoft as the value of accountId.

Mule Ref Doc : https://docs.mulesoft.com/http-connector/1.6/http-listener-ref#paths

Correct answer is Patients from year 2021.

The thing to note here is that year is not a query parameter and not the uri parameter. Hence it will filter all the patients and return the ones for whom year is 2021

URL parameters are always accessed using { } like => {customerID}

This kind of questions are best solved with filtering technique. Key thing to note here is XML attributes are always access by @ notation. So in this example orderId can be accessed as @OrderId which makes option 3 and option 4 false. Now difference in optin and option 2 is in mapping of lineItemPrice. Correct syntax to format a String in Numbse is value.price as Number. Hence option 2 is correct

Correct answer is process layer as all the orchestration and transformation logic should be in process layer as per Mulesoft's recommended approach for API led connectivity.

API-led connectivity is a methodical way to connect data to applications through reusable and purposeful APIs. These APIs are developed to play a specific role – unlocking data from systems, composing data into processes, or delivering an experience.

What are the APIs that enable API-led connectivity?

API-led connectivity provides an approach for connecting and exposing assets. With this approach, rather than connecting things point-to-point, every asset becomes a managed API – a modern API, which makes it discoverable through self-service without losing control.

The APIs used in an API-led approach to connectivity fall into three categories:

System APIs – these usually access the core systems of record and provide a means of insulating the user from the complexity or any changes to the underlying systems. Once built, many users, can access data without any need to learn the underlying systems and can reuse these APIs in multiple projects.

Process APIs – These APIs interact with and shape data within a single system or across systems (breaking down data silos) and are created here without a dependence on the source systems from which that data originates, as well as the target channels through which that data is delivered.

Experience APIs – Experience APIs are the means by which data can be reconfigured so that it is most easily consumed by its intended audience, all from a common data source, rather than setting up separate point-to-point integrations for each channel. An Experience API is usually created with API-first design principles where the API is designed for the specific user experience in mind.

The APIkit Router is a key message processor that validates requests against the provided definition, enriches messages (for example by adding default values to the messages) and routes requests to a particular flow. Also, the Router raises errors messages if errors occurs while routing, validating or processing the user request.

Correct answer is ${training.host}

1. Set Payload “Start”

2. 'Is Balnk String' Creates an Error object with #[error.description] =“String is not blank”

3. Default Error Handler catches and Propagates error

4. 'On Error Propogate' is 'RED IN RED OUT'. It Returns Status Code : 500 & #[error.description]

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Correct answer is String is not blank. Because validation component will throw an error as payload is not blank.

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Flow Reference Component

Flow Reference routes the Mule event to another flow or subflow, executes all processors in the referenced flow, and then routes the event back within the same Mule application. The following diagram shows the order of processing when one flow references another:

When the main flow is triggered, the Mule event travels through and executes the flow until the event reaches the Flow Reference. The event then travels through and executes the referenced flow from beginning to end, and then returns to the main flow.

This process enables you to treat the entire referenced flow like a single component in your current flow.

Mule Ref Doc : https://docs.mulesoft.com/mule-runtime/4.3/flowref-about

Correct answer is

• payload
• quantity var
• color query param

Mule event is correct answer. Mule event has two parts which are as follows

1) Message (which contains payload and attributes like headers and query/uri parameters

2) Variables

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Correct answer is Creates and manages discoverable assets to be consumed by line of business developers.

C4E does not get directly involved in projects.