Until successful component in mule demo

1. By
Sudha Ch

2.  The main motto of this PPT is how to use
Until Successful component in our
applications.

3.  The until-successful scope processes
messages through the processors within it
until the process succeeds. By default, until-
successful’s processing occurs
asynchronously from the main flow. After
passing a message into the until-successful
scope, the main flow immediately regains
control of the thread. However, you can
configure until-successful to run
synchronously relative to the main flow.

5.  .mflow
 <?xml version="1.0" encoding="UTF-8"?>
 <mule xmlns:vm="http://www.mulesoft.org/schema/mule/vm" xmlns:jdbc-ee="http://www.mulesoft.org/schema/mule/ee/jdbc" xmlns:http="http://www.mulesoft.org/schema/mule/http"
xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns:spring="http://www.springframework.org/schema/beans" version="EE-
3.4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-
current.xsd
 http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
 http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
 http://www.mulesoft.org/schema/mule/ee/jdbc http://www.mulesoft.org/schema/mule/ee/jdbc/current/mule-jdbc-ee.xsd
 http://www.mulesoft.org/schema/mule/vm http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd">
 <jdbc-ee:mssql-data-source name="MS_SQL_Data_Source" user=“****" password=“****" url="jdbc:sqlserver://localhost;databaseName=test1" transactionIsolation="UNSPECIFIED" doc:name="MS SQL
Data Source"/>
 <jdbc-ee:connector name="Database" dataSource-ref="MS_SQL_Data_Source" validateConnections="true" queryTimeout="-1" pollingFrequency="0" doc:name="Database"/>
 <spring:beans>
 <spring:bean id="Bean" name="Bean" class="org.mule.util.store.SimpleMemoryObjectStore"/>
 </spring:beans>
 <flow name="Database_ComponentFlow2" doc:name="Database_ComponentFlow2">
 <http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8087" path="UntilSuccessful" doc:name="HTTP"/>
 <logger message="--main flow--" level="INFO" doc:name="Logger"/>
 <expression-component doc:name="Expression"><![CDATA[
 sessionVars['DB_STATUS']='INITIAL';
 ]]></expression-component>
 <until-successful objectStore-ref="Bean" maxRetries="5" secondsBetweenRetries="5" doc:name="Until Successful" failureExpression="#[sessionVars['DB_STATUS']!='SUCCESS']">
 <vm:outbound-endpoint exchange-pattern="request-response" path="db" doc:name="VM"/>
 </until-successful>
 </flow>
 <flow name="Database_ComponentFlow3" doc:name="Database_ComponentFlow3">
 <vm:inbound-endpoint exchange-pattern="request-response" path="db" doc:name="VM"/>
 <jdbc-ee:outbound-endpoint exchange-pattern="request-response" queryKey="select" queryTimeout="-1" connector-ref="Database" doc:name="Database">
 <jdbc-ee:query key="select" value="select * from mytable1"/>
 </jdbc-ee:outbound-endpoint>
 <expression-component doc:name="Expression"><![CDATA[
 sessionVars['DB_STATUS']='SUCCESS';
 ]]></expression-component>
 <logger message="--success" level="INFO" doc:name="Logger"/>
 </flow>
 </mule>

6.  Output:

7.  Flow of execution:
1. URL to trigger the service from browser
http://localhost:8087/UntilSuccessful
2. Database component connects to the specific
database, executes the select query but there is
no table specified in DB, hence the until
successful component retries for 5 times and
exit the flow.

8.  https://docs.mulesoft.com/mule-user-
guide/v/3.5/until-successful-scope