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

This question validates you knowledge on Batch Processing. Before we analyze the question , lets revise a bit about batchfilters.

Batch Filters

You can apply one or more filters as attributes to any number of batch steps.Imagine a batch job whose first batch step checks if a Salesforce contact exists for a record, and a second batch step that updates each existing Salesforce contact with new information. You can apply a filter to the second batch step to ensure it only processes records that didn’t fail during the first batch step.By having batch steps accept only some records for processing, you streamline the batch job sothe Mule runtime engine can focus only on the relevant data for a particular batch step.

A batch step uses two attributes to filter records:

acceptExpression

acceptPolicy

Each batch step can accept one acceptExpression and one acceptPolicy attributes to filter records.

Use the acceptExpression attribute to process only records that evaluate to true; if the record evaluates to false, the batch step skips the record and sends it to the next one. In other words, the records with an accept expression that resolves to false are the ones that Mule filters out.

The example below filters out all records where the age is less than 21; the batch step does not process those records.

21]">

...

Mule Ref Doc : Refining Batch StepsProcessing | MuleSoft Documentation

As we are clear with above concepts , now lets understand this solution step by step.

1) Batch Step (Less than 50)

Accept expression for this batch step is less than 50. Hence elements which will go in this batch step are amount value 40 and 2. Hence output of logger in first batch step is

{amount=140}

{amount=102}

2) Batch Step (Greater than 20)

Accept condition for this batch step is greater than 20. Note that input amount values for this batch step are 100 , 140 and102 (last two values have been updated in batch step less than 50)

As all values satisfy this condition out put of second logger is

{step2amount=100}

{step2amount=140}

{step2amount=102}

Hence correct answer to this question is

{amount=140}

{amount=102}

{step2amount=100}

{step2amount=140}

{step2amount=102}

2) Batch Step (Greater than 20)

Accept condition for this batch step is greater than 20. Note that input amount values for this batch step are 100 , 140 and 102 (last two values have been updated inbatch step less than 50)

As all values satisfy this condition out put of second logger is

{step2amount=100}

{step2amount=140}

{step2amount=102}

Hence correct answer to this question is

{amount=140}

{amount=102}

{step2amount=100}

{step2amount=140}

{step2amount=102}

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 wrong2) hearders can be accessed with attributes. headers and not with only headers which makes option 4 incorrect

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

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

Correct answer is vars."customer"."firstName"

Please note that you can also access firstName using this syntax vars.customer.firstName.

Mule Ref Doc : Variables in Mule Apps | MuleSoft Documentation

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") }

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'

Pick First is not valid type. Rest all are valid type of event processor.

Choice : https://docs.mulesoft.com/mule-runtime/4.3/choice-router-concept

Round Robin : https://docs.mulesoft.com/mule-runtime/4.3/round-robin

First Successful : https://docs.mulesoft.com/mule-runtime/4.3/first-successful

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

Correct answer is Attributes.

Query parameters , URI parameters and headers are some of examples which are part of attributes.

Diagram Description automatically generated

Bottom of Form

Top of Form

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

Please refer to the belowscreenshot.

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

Correct answer is Merges elements of two lists (arrays) into a single list

MuleSoft Doc Reference : https://docs.mulesoft.com/mule-runtime/4.3/dw-core-functions-zip

Correct answer is Publish the API to Anypoint Exchange

Anypoint Exchange makes this possible bymaking it discoverable in below ways

1) In private exchange for internal developers

2) In a public portal for external developers/clients

Here is diagram created by me to help you understand sequence:

Diagram Description automatically generated

Correct answer is Creates a mock service for an API

API Notebook is an open source, shareable web application for API documentation, interactive API tutorial and example generatation, and a client for your API endpoints. Using API Notebook, you can make requests and quickly transform the responses into readable format. However it cannot be used to mock service for an API.

MuleSoft Doc Ref : https://docs.mulesoft.com/api-manager/1.x/api-notebook-concept

Creates reusable APIs and assets designed to beconsumed by other business units

* Watermark allows the poll scope to poll for new resources instead of getting the same resource over and over again.

* The database table must be ordered so that the“watermark functionality” can move effectively in the ordered list. Watermark stores the current/last picked up “record id.”

* If the Mule application is shut down, it will store the last picked up “record id” in the Java Object Store and the data will continue to exist in the file. This watermark functionality is valuable and enables developers to have increased transparency.

* Developers do not need to create code to handle caching; it is all configurable!

* There are two columns and both are unique butuser_id can't guaranty sequence whereas date_time will always be in increasing order and table content can easily be ordered on the basis of last processed date_time.

So correct answer is: Set the watermark column to the date_time column

This is a trick question.

You can callonly flows from DataWeave using lookup function. Note that lookup function does not support calling subflows.

A subflow needs a parent context to inherit behaviors from such as exception handling, which a flow does not need

Hence correct answer is Not possible in Mule 4

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]

--------------------------------------------------------------------------------------------------------------------------

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

A picture containing timeline Description automatically generated

Bottom ofForm

Top of Form

Correct syntax to use where clause is WHERE city = :city AND state = :state

This question validates knowledge on using dynamicqueries in DB select operation.

Configure Dynamic Queries in the Select Operation

When you need to parameterize not only the WHERE clause but also parts of the query itself (for example, queries that compare tables that depend on a condition, or complexqueries for which the project table columns need to vary), you can configure dynamic queries.

In the following example, you configure a dynamic query by using a full expression with a string in which the table depends on a variable $(vars.table). Althoughsome of the query text is dynamic ("SELECT * FROM $(vars.table)), the WHERE clause still defines the WHERE condition using input parameters: in this case, WHERE name = :name.

In your Studio flow, select the Select operation.

In the operation configurationscreen, set the SQL Query Text field to SELECT * FROM $(vars.table) WHERE name = :name.

Set the Input Parameters field to {'name' : payload}.

The following screenshot shows the configuration in Studio:

Graphical user interface, application Description automatically generated

Figure 3. Dynamic query configuration

In the XML editor, the  configuration looks like this:

#["SELECT * FROM $(vars.table) WHERE name = :name"]

#[{'name' : payload}]

You can apply input parameters only to parameters in a WHERE clause. To modify any other part of the query, use the DataWeave interpolation operator.

Mule Ref Doc: Query a Database Examples - Mule 4 | MuleSoft Documentation

Correct answer is APP: API RESOURCE NOT FOUND

---------------------------------------------------------------------------------------------------------------------------------------------------

1) A web client submits the request to the HTTP Listener.

2) The HTTP Request throws an "HTTP:NOT_FOUND" error, execution halts.

3) The On Error Propagate error Handler handles the error. In this case ,HTTP:NOT_FOUND error ismapped to custom error APP:API_RESOURCE_NOT_FOUND. This error processor sets payload to APP:API_RESOURCE_NOT_FOUND.

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

Reference Diagram:

Diagram Description automatically generated with medium confidence

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

APIKIt Creates a separate flow for each HTTP method

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

Themap 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:

Table Description automatically generated

Choice Router

The Choice router dynamically routes messages through a flow according to a set of DataWeave expressions that evaluate message content. Each expression is associated with a different routingoption. The effect is to add conditional processing to a flow, similar to an if/then/else code block in most programming languages.

Only one of the routes in the Choice router executes, meaning that the first expression that evaluates to true triggers thatroute’s execution and the others are not checked. If none of the expressions are true, then the default route executes.

Properties of

PropertyDescription

Expression (expression)

Expression in DataWeave language to evaluate input.If the expressionevaluates to true, this routing option is used:

Mulesoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.3/choice-route r-concept

With respect to above information ,

Option 1 is the correct syntax as others are incorrect because of below reasons

* Single = is not the correct syntax to validate the condition. It should be ==

* If keyword is not required in when condition.

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

Correct answer is Anypoint Visualizer

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

Anypoint Visualizer provides a real-time, graphical representation of the APIs, and Mule applications that are running and discoverable. It also displays third-party systems that are invoked by a Mule API, proxy, or application within your application network. The data displayed in the graph is dynamically updated and does not require prior configuration. Additionally, the data displayed is secure, as only users with the proper permissions can view the application network graph.

Diagram Description automatically generated

The current version of the RAML specification is 1.0

You can check RAML version in RAML definition by referring tofirst comment. See highlighted part in below image.

Graphical user interface, text, application, email Description automatically generated

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

As can be seen in error message , SOAP service findFlights expects the SOAP paylaod. This can be set using transform message processor which forms SOAP payload before the Consume operation that contains the destination query parameter

Choice router finds the FIRST true condition, then distribute the event to the ONE matched route.

MuleSoft Doc Ref: https://docs.mulesoft.com/mule-runtime/4.1/choice-router-concept

The Choice router dynamically routes messages through a flow according to a set of DataWeave expressions that evaluate message content. Each expression is associated with a different routing option. The effect is to add conditional processing to a flow, similar to an if/then/else code block in most programming languages.

Only one of the routes in the Choice router executes, meaning that the first expression that evaluates to true triggersthat route’s execution and the others are not checked. If none of the expressions are true, then the default route executes.

Diagram Description automatically generated

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.

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 isURL 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 nothappen 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 : HTTPListener Reference - Mule 4 | MuleSoft Documentation

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

Emptyarray is returned when no rows are matched.

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

Keyword to ad function in Dataweave transformation is fun. Hence option 2 and 4 are invalid. Also parameters needs to be passed exactly in same order as defined in function definition. Hence correct answer is'

fun addKV( object: Object, key: String, value: Any) =

object ++ {(key):(value)}

---

addKV ( {"hello': "world"}, "hola", "mundo" )

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

DataWeave FunctionDefinition Syntax

To define a function in DataWeave use the following syntax:

fun myFunction(param1, param2, ...) =

The fun keyword starts the definition of a function.

myFunction is the name you define for the function.

Function namesmust be valid identifiers.

(param1, param2, … , paramn) represents the parameters that your function accepts.

You can specify from zero to any number of parameters, separated by commas (,) and enclosed in parentheses.

The = sign marks the beginning of thecode block to execute when the function is called.

represents the actual code that you define for your function.