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<document>
    <properties>
        <title>Apache Synapse - Sample 59</title>
    </properties>
    <body>
        <section name="Sample 59: Weighted Round-Robin loadbalancing between 3 endpoints">
            <div class="xmlConf">&lt;?xml version="1.0" encoding="UTF-8"?&gt;
&lt;definitions xmlns="http://ws.apache.org/ns/synapse"&gt;
    &lt;sequence name="main" onError="errorHandler"&gt;
        &lt;in&gt;
            &lt;send&gt;
                &lt;endpoint&gt;
                    &lt;loadbalance
                            algorithm="org.apache.synapse.endpoints.algorithms.WeightedRoundRobin"&gt;
                        &lt;endpoint&gt;
                            &lt;address uri="http://localhost:9001/services/LBService1"&gt;
                                &lt;enableAddressing/&gt;
                                &lt;suspendOnFailure&gt;
                                    &lt;initialDuration&gt;20000&lt;/initialDuration&gt;
                                    &lt;progressionFactor&gt;1.0&lt;/progressionFactor&gt;
                                &lt;/suspendOnFailure&gt;
                            &lt;/address&gt;
                            &lt;property name="loadbalance.weight" value="1"/&gt;
                        &lt;/endpoint&gt;
                        &lt;endpoint&gt;
                            &lt;address uri="http://localhost:9002/services/LBService1"&gt;
                                &lt;enableAddressing/&gt;
                                &lt;suspendOnFailure&gt;
                                    &lt;initialDuration&gt;20000&lt;/initialDuration&gt;
                                    &lt;progressionFactor&gt;1.0&lt;/progressionFactor&gt;
                                &lt;/suspendOnFailure&gt;
                            &lt;/address&gt;
                            &lt;property name="loadbalance.weight" value="2"/&gt;
                        &lt;/endpoint&gt;
                        &lt;endpoint&gt;
                            &lt;address uri="http://localhost:9003/services/LBService1"&gt;
                                &lt;enableAddressing/&gt;
                                &lt;suspendOnFailure&gt;
                                    &lt;initialDuration&gt;20000&lt;/initialDuration&gt;
                                    &lt;progressionFactor&gt;1.0&lt;/progressionFactor&gt;
                                &lt;/suspendOnFailure&gt;
                            &lt;/address&gt;
                            &lt;property name="loadbalance.weight" value="3"/&gt;
                        &lt;/endpoint&gt;
                    &lt;/loadbalance&gt;
                &lt;/endpoint&gt;
            &lt;/send&gt;
            &lt;drop/&gt;
        &lt;/in&gt;
        &lt;out&gt;
            &lt;send/&gt;
        &lt;/out&gt;
    &lt;/sequence&gt;
    &lt;sequence name="errorHandler"&gt;
        &lt;makefault response="true"&gt;
            &lt;code xmlns:tns="http://www.w3.org/2003/05/soap-envelope" value="tns:Receiver"/&gt;
            &lt;reason value="COULDN'T SEND THE MESSAGE TO THE SERVER."/&gt;
        &lt;/makefault&gt;
        &lt;send/&gt;
    &lt;/sequence&gt;
&lt;/definitions&gt;</div>
            <subsection name="Objective">
                <p>
                    Objective: Demonstrate the weighted load balancing among a set of
endpoints
                </p>
            </subsection>
            <subsection name="Pre-requisites">
                <p>
                    <ul>
                    <li>Start ESB with sample configuration 59. (i.e. wso2esb-samples -sn 59) </li>

                    <li>Deploy the LoadbalanceFailoverService and start three instances of sample Axis2 server as mentioned in sample 52.</li>

                    <li>Above configuration sends messages with the weighted loadbalance behaviour. Weight of each leaf
                        address endpoint is defined by integer value of "loadbalance.weight" property associated with each endpoint.
                        If weight of a endpoint is x, x number of requests will send to that endpoint before switch to next active endpoint.
                        <br/>To test this, run the loadbalancefailover client to send 100 requests as follows: </li>
                    </ul>
                </p>
            </subsection>
            <subsection name="Executing the Client">
                <p>
                    Invoke the sample client as follows
                </p>
                <div class="command">ant loadbalancefailover -Di=100</div>
                <p>This client sends 100 requests to the LoadbalanceFailoverService through
                    ESB. ESB will distribute the load among the three endpoints mentioned in the
                    configuration in weighted round-robin manner. LoadbalanceFailoverService appends the
                    name of the server to the response, so that client can determine which server
                    has processed the message. If you examine the console output of the client,
                    you can see that requests are processed by three servers as follows: </p>
                <div class="consoleOutput">[java] Request: 1 ==&gt; Response from server: MyServer1
                    [java] Request: 2 ==&gt; Response from server: MyServer2
                    [java] Request: 3 ==&gt; Response from server: MyServer2
                    [java] Request: 4 ==&gt; Response from server: MyServer3
                    [java] Request: 5 ==&gt; Response from server: MyServer3
                    [java] Request: 6 ==&gt; Response from server: MyServer3
                    [java] Request: 7 ==&gt; Response from server: MyServer1
                    [java] Request: 8 ==&gt; Response from server: MyServer2
                    [java] Request: 9 ==&gt; Response from server: MyServer2
                    [java] Request: 10 ==&gt; Response from server: MyServer3
                    [java] Request: 11 ==&gt; Response from server: MyServer3
                    [java] Request: 12 ==&gt; Response from server: MyServer3
                    ...
                </div>
                <p>As logs, endpoint with weight 1 received a 1 request and endpoint with weight 2 received 2
                    requests and etc... in a cycle</p>
             </subsection>
        </section>
        <p>
            <a href="../samples.html">Back to Catalog</a>
        </p>
    </body>
</document>
