MCD-Level-1 Practice Exam Questions with Answers MuleSoft Certified Developer - Level 1 (Mule 4) Certification

Correct answer is an operation. For each method of the RAML specification , REST connect module provide an operation.

Please refer to the below screenshot.

Option 1 is the only correct choice due to two reasons. 1) Concatenation is always with ++ sign and not with + sign which makes option 2 and 3 wrong 2) hearders can be accessed with attributes. headers and not with only headers which makes option 4 incorrect

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

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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.

Anypoint Exchange provided a way to publish , share and search API's.

MuleSoft Doc Ref : https://docs.mulesoft.com/exchange/

Process section is must to get compiles. Process section must have one or more processors

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Correct answer is The API interfaces are specified at a granularity intended for developers to consume specific aspect of integration processes

Correct answer is as below as concatenation operation works only with string and not with the objects. In this case payload is object.

"You called the function '++' with these arguments:

1: String ("INFO")

2: Object ({student: {name: "Anay" as String {class: "java.lang.String"},age

Setting Breakpoints

To set breakpoints, right-click a building block, then select Toggle Breakpoint.

Studio applies a red dot to the building block’s icon on the canvas.

When you run your application in Debug mode, Studio stops the flow execution at the breakpoint you have set, allowing you to check the Mule Event content in the Mule Debugger View.

Mule Ref Doc : Setting Breakpoints | MuleSoft Documentation

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Here’s specifically what is happening here:

1) Payload is successfully set to “Before”

2) Is null validation is used which will pass the message only if payload is null. In this case as payload is not null, it creates an Error Object. Flow execution stops

#[error.description] = “Validation error”

3) Because no error handler is defined, the Mule default error handler handles the error

4) “Validation error” is the error message returned to the requestor in the body of the HTTP request with HTTP Status Code: 500

Reference diagram:

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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.

You can choose Attach Project Sources to include metadata that Studio requires to reimport the deployable file as an open Mule project into your workspace. You must keep the Attach Project Sources option selected to be able to import the packaged JAR file back into a Studio workspace. But requirement here is to create smallest deployable archive that will successfully deploy to Cloudhub. Hence we can ignore this option.

We need to select Include project module and dependencies

As actual modules and external dependencies required to run the Mule application in a Mule runtime engine

Hence correct answer is

Select only below option 2) Include project module and dependencies

MuleSoft Doc Ref : https://docs.mulesoft.com/studio/7.5/import-export-packages#exporting-a-studio-project-to-a-deployable-mule-application

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

Gold is not valid category for connector types.

MuleSoft Doc Ref : https://docs.mulesoft.co m/mule-runtime/3.7/anypoint-connectors#connector-support-categories

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Correct answer is 200.1234 as String {format: ".0#"} . Rest all options are not syntactically correct.

As can be seen in RAML, POST expects input in application/json format which eliminates two of the options as two options are in xml format.

Now out of the two remaining options, one has id field in request which is only mentioned for get response and not for POST request. Hence id field is not expected in POST request.

Hence correct answer is

{

"name": "GoerdiLa Forge",

"address": "1 Westland CA",

"customer_since": "2014-01-04",

"balance": "4829.29",

"bank_agend_id": "12556"

}

Correct answer is System layer

System APIs provide a means for insulating the data consumers from the complexity or changes to the underlying backend systems.

MuleSoft recommends three-layered approach to API-led connectivity, highlighting the three layers:

* System APIs

* Process APIs

* Experience APIs

System APIs are the core systems of record underlying core systems of record (e.g. ERPs, key customer and billing systems, databases, etc.). Process APIs allow you to define a common process which the organization can share, and these APIs perform specific functions, provide access to non-central data, and may be built by either Central IT or Line of Business IT. And finally, the 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.

The three-layered structure allows for a seamless flow of data from systems of record to new experiences, and allows for reusability of assets rather than point to point connections. This approach provides a distributed and tailored approach to architecture, greater flexibility through loose coupling, and deeper operational visibility into what is being built.

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Correct answer is Subflow has no error handling implementation where as sync flow has.

Subflow

A subflow processes messages synchronously (relative to the flow that triggered its execution) and always inherits both the processing strategy and exception strategy employed by the triggering flow. While a subflow is running, processing on the triggering flow pauses, then resumes only after the subflow completes its processing and hands the message back to the triggering flow.

Synchronous Flow

A synchronous flow, like a subflow, processes messages synchronously (relative to the flow that triggered its execution). While a synchronous flow is running, processing on the triggering flow pauses, then resumes only after the synchronous flow completes its processing and hands the message back to the triggering flow. However, unlike a subflow, this type of flow does not inherit processing or exception strategies from the triggering flow.

This type of flow processes messages along a single thread, which is ideally suited to transactional processing

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"

}

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 as below.After all processing routes have finished execution, the Scatter-Gather component creates a new Mule event that combines all resulting Mule events from each route, and then passes the new Mule event to the next component in the flow.

{

"0": {

"attributes": ...,

"payload": "100"

},

"1": {

"attributes": ...,

"payload": "200"

}

}

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The correct answer is To avoid duplicate processing of records in a database.

If a watermark column is provided, the values taken from that column are used to filter the contents of the next poll, so that only rows with a greater watermark value are returned. If an ID column is provided, this component automatically verifies that the same row is not picked twice by concurrent polls.

Mule doc reference : https://docs.mulesoft.com/db-connector/1.8/database-documentation#listener

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

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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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

Empty array is returned when no rows are matched.

MuleSoft Doc Ref : https://docs.mulesoft.com/db-connector/1.9/database-connector-select

Sequence can be described as follows.

* When web client sends the request , it sends payload as Blue (mentioned in question)

* In first iteration this will go to default choice , which sets payload to Red

* Via default route , flow will call itself with payload as Red

* In second iteration , as payload is Red , it will go to first route in choice router which will set payload to Blk and second iteration will end returning back payload as Blk to first iteration.

* This Blk will be again set to payload and first iteration will end returning back response as Blk

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

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

Centre for Enablement (C4E) is an IT operating model that enables an enterprise to build reusable assets, accumulate API’s, leverage best practices and knowledge to enable self service and efficient delivery in the organization and implement new solutions faster

Correct answer is Configure the correct JDBC driver as error message suggests the same

• Caused by: java.sql.SQLException: Error trying to load driver: com.mysql.jdbc.Driver : Cannot load class 'com.mysql.jdbc.Driver': [
• Class 'com.mysql.jdbc.Driver' has no package mapping for region 'domain/default/app/mule_app'.,
• Cannot load class 'com.mysql.jdbc.Driver': [

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

Database always return rows as an array.

Array is the correct answer

Scatter-Gather sends the event to each routes concurrently. Hence both route in this example will start in parallel. So total time to complete processing is 40 seconds

The Scatter-Gather component is a routing event processor that processes a Mule event through different parallel processing routes that contain different event processors. Each route receives a reference to the Mule event and executes a sequence of one or more event processors. Each of these routes uses a separate thread to execute the event processors, and the resulting Mule event can be either the same Mule event without modifications or a new Mule event with its own payload, attributes, and variables. The Scatter-Gather component then combines the Mule events returned by each processing route into a new Mule event that is passed to the next event processor only after every route completes successfully.

The Scatter-Gather component executes each route in parallel, not sequentially. Parallel execution of routes can greatly increase the efficiency of your Mule application and may provide more information than sequential processing.

Mule Ref Doc : https://docs.mulesoft.com/mule-runtime/4.3/scatter-gather-concept

Correct answer is An Object containing all three Mule event Objects

The Scatter-Gather component is a routing event processor that processes a Mule event through different parallel processing routes that contain different event processors. Each route receives a reference to the Mule event and executes a sequence of one or more event processors. Each of these routes uses a separate thread to execute the event processors, and the resulting Mule event can be either the same Mule event without modifications or a new Mule event with its own payload, attributes, and variables. The Scatter-Gather component then combines the Mule events returned by each processing route into a new Mule event that is passed to the next event processor only after every route completes successfully.

The Scatter-Gather component executes each route in parallel, not sequentially. Parallel execution of routes can greatly increase the efficiency of your Mule application and may provide more information than sequential processing.

Sample output is as below

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MuleSoft Documentation reference : https://docs.mulesoft.com/mule-runtime/4.3/scatter-gather-concept

String is the correct answer as XML is of an Object type String

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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Variables are stored under Mule event. Please refer to below image for the hierarchy .

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Correct answer is below as it follows the correct syntax.

/customers:

/{customerId}:

get:

WSDL is used to define the contract in case of SOAP . RAML/OAS is used to REST services

Note that private flow has error scope defined as On Error Continue . So when error occurs in private flow , it is handled by this On Error Continue scope which sends success response back to main flow and does not throw back an error. So main continues normally and payload is set to Success - main flow.

Hence correct answer is Success - main flow

1) HTTP listener received request

2) The Flow Reference calls the child flow

3) The Is Number validator creates an Error Object because the payload isn’t an integer. Child Flow execution stops

#[error.description] = “payload is not a valid INTEGER value”

#[error.errorType] = VALIDATION:INVALID_NUMBER

4) The On Error Continue handles the errorThe payload is set to “Error – Sub Flow”

5) “Error – Sub Flow” is returned to the main flow as if the child flow was a success. The Set Payload is executed. The payload is reset to “Success – Finished Main Flow”

6) “Success – Main Flow” is returned to the requestor in the body of the HTTP request. HTTP Status Code: 200

As you can see, in the above example, because the error was caught by an On Error Continue scope in the child flow (RED in, GREEN out) when the Mule Message returns to the parent flow, the parent flow knows none-the-different that there was a failure because the on error continue returns a 200 success message. Note that because, to the mainFlow, the childFlow appeared to succeed, the processing of mainFlow resumed after the flow reference.

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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.

lookup(String, Any, Number)

This function enables you to execute a flow within a Mule app and retrieve the resulting payload.

It works in Mule apps that are running on Mule Runtime version 4.1.4 and later.

Similar to the Flow Reference component (recommended), the lookup function enables you to execute another flow within your app and to retrieve the resulting payload. It takes the flow’s name and an input payload as parameters. For example, lookup("anotherFlow", payload) executes a flow named anotherFlow.

Correct answer is

lookup( "createCustomerObject", {first: "Aice, last: "Green"})

MuleSoft Documentation Reference : https://docs.mulesoft.com/mule-runtime/4.3/dw-mule-functions-lookup

Returns an array that is the result of applying a transformation function (lambda) to each of the elements.

MuleSoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.3/dataweave-cookbook-map

The map operator is a function in Dataweave which iterates over the items in an array and outputs them into a new array. It basically accepts input as a list of items in an array and manipulates the items in the array in order to form a new array as an output.

I have created below chart for your easier understanding:

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Points to remember:

* XML must have a root element.

* XML only allows one root element

* To avoid multiple root issues, you must create a root element for the XML output, whenever we transform output

* When mapping array elements (JSON or JAVA) to XML, wrap the map operations in {(..)}

-{ } are defining the object

( ) are transforming each element in the array as a key/value pair

* The transformation to XML would fail if the above mentioned considerations were not taken into account.

* Thus the transformation script declares a root element as trains and wraps the data in “{( )}“.

Whenever you see such type of question, always look out for root element followed by {( )} wrapping map.

I call this a "Wrap The Map" scenario. Hope it would help you remember !

You can define your own DataWeave functions using the fun declaration in the header of a DataWeave script. Sample is as below. ----------------------------------------

%dw 2.0

output application/json

fun toUpper(aString) = upper(aString)

---

toUpper("hello")

MuleSoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.1/dataweave-functions

The List operation returns an array of messages in which: Each message holds the file’s content in its payload. The file’s attributes section carries the file’s metadata (such as name, creation time, and size). The payload is empty if the element is a folder.