Retry when Call Mediator fails in In-Sequence WSO2 ESB

Hi All,
This blog post is to show how you could retry when the there is an issue in the in-sequence.

Flow
when the proxy is invoked it will hit the in-sequence(foo) and if there is an issue, onError sequence will be called(retryError).
In the bellow retryError sequence it will check if the error is occurred from login request failure, then it will retry (call back) the foo .
I have specified the retry count as 2 and have added a tread sleep between retries.

How to configure
1. Add this foo sequence as a seperate sequence and use in the proxy service In-Sequence
 Add an onError option to the sequence
e.g -

<sequence name="foo" onError="retryError" xmlns="http://ws.apache.org/ns/synapse">
    <log>
        <property name="Test" value="Inside the in sequence"/>
    </log>
    <call blocking="true">
        <endpoint>
            <address uri="http://localhost:9000/services/SimpleStockQuoteService"/>
        </endpoint>
    </call>
</sequence>

2. Create a new sequence retryError and the bellow code

<?xml version="1.0" encoding="UTF-8"?>
<sequence name="retryError" xmlns="http://ws.apache.org/ns/synapse">
    <filter xmlns:ns="http://org.apache.synapse/xsd"
        xmlns:ns3="http://org.apache.synapse/xsd" xpath="get-property('retry_count')">
        <then>
            <property expression="number(get-property('retry_count'))+1"
                name="retry_count" scope="default"/>
            <filter xpath="get-property('retry_count') > 2">
                <then>
                    <log/>
                    <drop/>
                </then>
                <else>
                    <script language="js"><![CDATA[java.lang.Thread.sleep(5000);]]></script>
                    <clone continueParent="true" sequential="false">
                        <target sequence="foo"/>
                    </clone>
                </else>
            </filter>
        </then>
        <else>
            <script language="js"><![CDATA[java.lang.Thread.sleep(5000);]]></script>
            <property name="retry_count" scope="default" type="STRING" value="1"/>
            <clone continueParent="true" sequential="false">
                <target sequence="foo"/>
            </clone>
        </else>
    </filter>
</sequence>

 If you have an easy way to do this feel free to comment

Have Fun !!!!