Salesforce-MuleSoft-Developer-I Salesforce Certified MuleSoft Developer (Mule-Dev-201) Questions and Answers

Correct answer is Save the payload from the Database SELECT operation to a variable

Response from HTTP requestwill override the payload and hence response of database SELECT can be lost. Best way to preserve is to assign payload of first operation to variable using TransformMessage.

Correct answer is Change the method attributes value to "POST".

It can be fixed in either of the two ways as below.

1) Changing method attribute to POST in ClientRequestFlow

2) Setting allowedMethods as PUT in ShippingFlow (but doesn't fit as question mentions about changing ClientRequestFlow)

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 thisexample 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

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

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 answeris

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

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

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

C4E does not get directly involved in projects.

Correct answer is A global element

Global error handlers are to be created in global element .

Quick note to remember here is Global error handlers come in to pictureonly when there are no error handlers specified as flow level.

Steps to create Global error handler

1) Click Global Elements to open Global Configuration Elements. Global Elements is located below the Studio canvas

2) In Global Configuration Elements,click Create to open the Choose Global Type dialog

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3) From the dialog, select Global Configuration -→ Configuration, and then click OK to open the Configuration dialog.

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4) From the select Configuration dialog, select allErrorHandler for the Default Error Handler field, and click OK.

You can define your own DataWeave functionsusing 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

Correct answer is Mule runtime

DataWeave is the MuleSoft expression language for accessing and transforming data that travels through a Mule app. DataWeave is tightly integrated with the Mule runtime engine, which runs the scripts and expressions in your Mule app.

Mule Doc Reference : https://docs.mulesoft.com/mule-runtime/4.3/dataweave

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

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

Stepsto 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

Root element is always required while creating XML response in DataWeave transformation

Correctanswer is [[5, 10, 15, 20], 5]

Key thing to note here is that any changes made to payload in for each loop are not available outside for each scope where as variable value updated in for each loop is visible out side for each loop too.

In this example , sequence can be described as follows

1) Payload is set to the value [5, 10, 15, 20]

2) Variable is set to the value of 1

3) For each loop is executed four times and in each loop payload value is updated to append "Req" and variable is count is increased by 1

4) Once control comes out of for each , payload changes made within for each are not visible. Hence payload at this point of time is equal to payload available before entering for each loop which was  [5, 10, 15, 20]. Similarly variable value updated in for each loop is also available outside hence variable value is 5 as it was updated in loop.

5) Hence correct answer is [[5, 10, 15, 20], 5]

For Each Scope

The For Each scope splits a payload into elements and processes them one by one through the components that you place in the scope. It is similar to a for-each/for loop code block in most programming languages and can process any collection, including lists and arrays. The collection can be any supported content type, such as application/json, application/java, or application/xml.

General considerations about the For Each scope:

By default, For Each tries to split the payload. If the payload is a simple Java collection, the For Each scope can split it without any configuration. The payload inside the For Each scope is each of the split elements. Attributes within the original message are ignored because they are related to the entire message.

For Each does not modify the current payload. The output payload is the same as the input.

For non-Java collections, such as XML or JSON, use a DataWeave expression to split data. Use the Collection field for this purpose.

Correct answer is

%dw 2.0

output application/json

import modules::Utility

---

Utility::encryptString( "John Smith" )

DataWeave 2.0 functions are packaged in modules. Before you begin, note that DataWeave 2.0 is for Mule 4apps. For Mule 3 apps, refer to DataWeave Operators in the Mule 3.9 documentation. For other Mule versions, you can use the version selector for the Mule Runtime table of contents.

Functions in the Core (dw::Core) module are imported automatically into your DataWeave scripts. To use other 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:

import dw::core::Strings

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

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. For example, this import directive does not identify any functions to import from the String module, so it calls the pluralize function like this: Strings::pluralize("box").

Transform

%dw 2.0

import dw::core::Strings

output application/json

---

{ 'plural': Strings::pluralize("box") }

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

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Lets revise few concepts RAML which can help us to find the answer of this question.

URI Parameters

Lets have a look at below example.

/foos:

/{id}:

/name/{name}:

Here, the braces { } around property names define URI parameters. They represent placeholders in each URI anddo not reference root-level RAML file properties as we saw above in the baseUri declaration. The added lines represent the resources /foos/{id} and /foos/name/{name}.

Query Parameters

Now we'll define a way to query the foos collection using query parameters. Note that query parameters are defined using the same syntax that we used above for data types:

/foos:

get:

description:ListallFoosmatching query criteria,ifprovided;

otherwise list allFoos

queryParameters:

name?:string

ownerName?:string

Based on the above information , below is the only option which defines storeid as uri parameter and department as query parameter.

/{storeId}:

get:

queryParameter:

department:

Correct answer is */status as it is the correct way to use wildcards while configuring path value in HTTP listener

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

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

Please refer to the belowscreenshot.

1. SetPayload “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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Option 1 is the correct syntax

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

Correct answer is ${training.host}

Sequence can be described as follows.

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

* 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 setpayload 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

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

For Each Scope

The For Each scope splits a payload into elements and processes them one by one through the components that you place in the scope. It is similar to a for-each/for loop code block in most programminglanguages and can process any collection, including lists and arrays. The collection can be any supported content type, such as application/json, application/java, or application/xml.

General considerations about the For Each scope:

By default, For Each tries to split the payload. If the payload is a simple Java collection, the For Each scope can split it without any configuration. The payload inside the For Each scope is each of the split elements. Attributes within the original message are ignored becausethey are related to the entire message.

For Each does not modify the current payload. The output payload is the same as the input.

Mule Doc Reference : https://docs.mulesoft.com/mule-runtime/4.3/for-each-scope-concept

Core (dw::Core) This module contains core DataWeave functions for data transformations. It is automatically imported into any DataWeave script.

Flow Reference Component

Flow Reference routes the Mule event to another flow orsubflow, 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 Muleevent 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

quantityvar

colorquery param

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

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

Correct answer is 0.1 vCores

MuleSoft Doc Ref :https://docs.mulesoft.com/runtime-manager/cloudhub-architecture#cloudhub-workers

CloudHub Workers

Workers are dedicated instances of Mule runtime engine that run your integration applications on CloudHub. The memory capacity and processing power of a worker depends on how you configure it at the application level.

Worker sizes have different compute, memory, and storage capacities. You can scale workers vertically by selecting one of the available worker sizes:

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Correct answer is MAJOR

MAJOR version when you make incompatible API changes, MINOR version when you add functionality in a backwards compatible manner, and PATCH version when you make backwards compatible bug fixes.

For details refer to this documentation : https://semver.org/

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

Metadata is stored in application-types.xml flle located under src/main/resources.

Mule 4 applications contain an application-types.xml file, which is where metadata around your data types is stored. For example, if you createa new CSV type, that metadata will be added to this file. This new file is easy to share, commit, and merge when conflicts arise, which enables you to do more metadata-driven development.

MuleSoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.3/intro-studio#metadata-storage

Debugger can be used to debug applications to see event data movine from one flow to other

Correct answer isArray.

Flatten turns a set of subarrays (such as [ [1,2,3], [4,5,[6]], [], [null] ]) into a single, flattened array (such as [ 1, 2, 3, 4, 5, [6], null ]).

This example defines three arrays of numbers, creates another array containing those three arrays, and then uses the flatten function to convert the array of arrays into a single array with all values.

Source

%dw 2.0

output application/json

var array1 = [1,2,3]

var array2 = [4,5,6]

var array3 = [7,8,9]

var arrayOfArrays = [array1, array2, array3]

---

flatten(arrayOfArrays)

Output

[ 1,2,3,4,5,6,7,8,9 ]

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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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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

Error in validation component will get processed by Processer level On Error Propagate block and thenerror will be rethrown which will get processed by flow level error handler which will set payload to "Error- main flow". Hence correct answer is Error - main flow

1) Request is received by HTTP listener

2) Try scope gets executed

3) The validator component in the Try scope creates an Error Object because the payload is not null.

4) The On Error Propagate handles the error. The payload is set to “Error – Try scope”

6) “Error – Try scope” is returned to the 'On Error Continue' block. Main flow execution stops. Payload is set to "Error - main flow"

7) “Error - main flow” is returned to the requestor in the body of the HTTP request. HTTP Status Code: 200

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Reference Diagram though not exactly same, conditions are similar. They will help you answer any new question on error handling in real exam:

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https://docs.mulesoft.com/mule-runtime/4.3/on-error-scope-concept#on-error-continue

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

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

Causedby:java.sql.SQLException:Errortrying to load driver:com.mysql.jdbc.Driver:Cannotloadclass'com.mysql.jdbc.Driver':[

Class'com.mysql.jdbc.Driver'hasnopackagemappingforregion'domain/default/app/mule_app'.,

Cannotloadclass'com.mysql.jdbc.Driver':[

Attributes are replaced with new attributes from the HTTP Request response.

Attributes include everything apart from Payload/body. For ex: Headers, query parameters, URI parameters.

So, when outbound HTTP request is made, new attributes need to passthe outbound HTTP request and old attributes are replaced.

I have created below diagram to make it easy for you to understand:

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Cloudhub exposeservices on port 8081 and override value in http.port with this one .

Sample log in Runtime Manager is below

21:15:53.148 08/08/2021 Worker-0 ArtifactDeployer.start.01 INFO

Listening for connections on 'http://0.0.0.0:8081 '

First step in creating Modern API is to create an API specification and get feedback from stakeholders so that any future issues can be identified at early stage thereby reducing overall delivery time

Logs would look like:

INFO 2021-06-09 19:14:56,039[[MuleRuntime].uber.06: [validationtest].batch-job-validationtestBatch_Job-work-manager @6de10f3e] [processor:validationtestFlow/processors/1/route/0/route/0/aggregator/processors/0; event: bfb751e1-9939-11eb-9f69-02053763653a] org.mule.runtime.core.internal.processor.LoggerMessageProcessor:

[

“\”A\””,

“\”C\””,

“\”D\””

]

—-

INFO 2021-06-09 19:15:02,486 [[MuleRuntime].uber.06: [validationtest].batch-job-validationtestBatch_Job-work-manager @6de10f3e] [processor: validationtestFlow/processors/1/route/0/route/0/aggregator/processors/0; event: bfb751e1-9939-11eb-9f69-02053763653a] org.mule.runtime.core.internal.processor.LoggerMessageProcessor: [

“\”E\””

]

Batch aggregator value is 3. Hence in first time it will print [“A”, “C”, “D”] and in next iteration it will print [ “E” ]

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Correct answer is [ “E” ]

Its primary function is to design and develop fully functional Mule applications in a hosted development environment.

To compare, DataWeave syntax is #[payload == "FR"].

In this case only one = is used so it will give syntax error.

Hence the correct answer is A dataweave syntax error

Correct answer is /accounts?account_type=retail&industry=finance

Query parameters are a defined set of parameters attached to the end of a url. They are extensions of the URL that are used to helpdefine specific content or actions based on the data being passed. To append query params to the end of a URL, a ‘?’ Is added followed immediately by a query parameter.

To add multiple parameters, an ‘&’ is added in between each.

The HTTP 415 Unsupported Media Type client error response codeindicates 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. Asper RAML input is expected in application/xml.

Hence correct answer is Set a request header with the name Content-Type to a