Sample 154: Load Balancing with Proxy Services

Objective: Load Balancing with Proxy Service.

<definitions xmlns="http://ws.apache.org/ns/synapse">
    <proxy name="LBProxy" transports="https http" startOnLoad="true">
        <target faultSequence="errorHandler">
            <inSequence>
                <send>
                    <endpoint>
                        <session type="simpleClientSession"/>
                        <loadbalance algorithm="org.apache.synapse.endpoints.algorithms.RoundRobin">
                            <endpoint>
                                <address uri="http://localhost:9001/services/LBService1">
                                    <enableAddressing/>
                                    <suspendDurationOnFailure>20</suspendDurationOnFailure>
                                </address>
                            </endpoint>
                            <endpoint>
                                <address uri="http://localhost:9002/services/LBService1">
                                    <enableAddressing/>
                                    <suspendDurationOnFailure>20</suspendDurationOnFailure>
                                </address>
                            </endpoint>
                            <endpoint>
                                <address uri="http://localhost:9003/services/LBService1">
                                    <enableAddressing/>
                                    <suspendDurationOnFailure>20</suspendDurationOnFailure>
                                </address>
                            </endpoint>
                        </loadbalance>
                    </endpoint>
                </send>
                <drop/>
            </inSequence>
            <outSequence>
                <send/>
            </outSequence>
        </target>
        <publishWSDL uri="file:repository/samples/resources/proxy/sample_proxy_2.wsdl"/>
    </proxy>
    <sequence name="errorHandler">
        <makefault>
            <code value="tns:Receiver" xmlns:tns="http://www.w3.org/2003/05/soap-envelope"/>
            <reason value="COULDN'T SEND THE MESSAGE TO THE SERVER."/>
        </makefault>
        <header name="To" action="remove"/>
        <property name="RESPONSE" value="true"/>
        <send/>
    </sequence>
</definitions>

Prerequisites

Start the Synapse configuration numbered 154: wso2esb-samples.sh -sn 154
Start three instances of Axis2 server (on ports 9001, 9002, and 9003), and deploy the LBService to each of them. For more information, see Setting Up the ESB Samples.

Run the client:

ant loadbalancefailover -Dmode=session -Dtrpurl=http://localhost:8280/services/LBProxy