Objective: Demonstrate how to use endpoint templates in a load balance configuration.
<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 name="templ_ep1" template="endpoint_template" uri="http://localhost:9001/services/LBService1"> <parameter name="suspend_duration" value="5"/> </endpoint> <endpoint name="templ_ep2" template="endpoint_template" uri="http://localhost:9002/services/LBService1"> <parameter name="suspend_duration" value="20"/> </endpoint> <endpoint name="templ_ep3" template="endpoint_template" uri="http://localhost:9003/services/LBService1"> <parameter name="suspend_duration" value="200"/> </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> <send/> </sequence> <template name="endpoint_template"> <parameter name="suspend_duration"/> <endpoint name="annonymous"> <address uri="$uri"> <enableAddressing/> <suspendDurationOnFailure>$suspend_duration</suspendDurationOnFailure> </address> </endpoint> </template> </definitions>
Prerequisites:
- Sample setup is same as LoadBalance endpoint scenario (#154).
- Start the Synapse configuration numbered 752: i.e. wso2esb-samples -sn 752
- Start the Axis2 server and deploy the LoadbalanceFailoverService if not already done
Configuration demonstrates a single endpoint template named 'endpoint_template'. Three endpoint templates are created inside loadbalance endpoint which will point to this template. Note different parameters passed on to the same template ie:- service url and suspend duration as parameters
Invoke the client as follows.
ant loadbalancefailover -Dmode=session -Dtrpurl=http://localhost:8280/services/LBProxy
As in the previous loadbalance samples client console will show loadbalance requests going towards three endpoints created from the same template. Notice differnt suspension times for three services in a failed endpoint scenario as well. (reflects different parameters passed onto the template).