Chapter 9. Enabling High Availability in Fuse Fabric

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    ...
    xmlns:osgi="http://www.springframework.org/schema/osgi"
    ...
    xmlns:cxfcore="http://cxf.apache.org/core"
>
    ...
    <!-- Reference the fabric agent -->
    <osgi:reference id="IZKClient"
        interface="org.linkedin.zookeeper.client.IZKClient" />

    <!-- Configure the Fabric load balancer feature -->
    <bean id="fabricLoadBalancerFeature"
          class="org.fusesource.fabric.cxf.FabricLoadBalancerFeature">
        <property name="zkClient" ref="IZKClient" />
        <property name="fabricPath" value="ZKPath" />
    </bean>

    <!-- Add the feature to the bus -->
    <cxfcore:bus>
      <cxfcore:features>
        <ref bean="fabricLoadBalancerFeature" />
      </cxfcore:features>
    </cxfcore:bus>
    ...
</beans>

<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
           ...
           xmlns:cxf="http://cxf.apache.org/blueprint/core"
           ...
>
    ...
    <!-- Reference the fabric agent -->
    <reference id="org.linkedin.zookeeper.client.IZKClient"
               interface="org.linkedin.zookeeper.client.IZKClient" />

    <!-- Create the Fabric load balancer feature -->
    <bean id="fabricLoadBalancerFeature"
          class="org.fusesource.fabric.cxf.FabricLoadBalancerFeature">
        <property name="zkClient" ref="org.linkedin.zookeeper.client.IZKClient" />
        <property name="fabricPath" value="ZKPath" />
    </bean>

    <!-- setup the feature on the bus to help publish the services to the fabric-->
    <cxf:bus bus="cxf">
        <cxf:features>
            <ref component-id="fabricLoadBalancerFeature"/>
        </cxf:features>
    </cxf:bus>
    ...
</blueprint>

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    ...
    xmlns:jaxws="http://cxf.apache.org/jaxws"
    xmlns:osgi="http://www.springframework.org/schema/osgi"
    ...
>
    <!-- Create a client proxy, with load balancing enabled -->
    <jaxws:client id="ClientProxyBeanID"
        address="http://dummyaddress"
        serviceClass="SEI">
        <jaxws:features>
            <ref bean="fabricLoadBalancerFeature" />
        </jaxws:features>
    </jaxws:client>
    ...
    <!-- Reference the fabric agent -->
    <osgi:reference id="IZKClient"
        interface="org.linkedin.zookeeper.client.IZKClient" />

    <!-- Configure the Fabric load balancer feature -->
    <bean id="fabricLoadBalancerFeature"
          class="org.fusesource.fabric.cxf.FabricLoadBalancerFeature">
        <property name="zkClient" ref="IZKClient" />
        <property name="fabricPath" value="ZKPath" />
    </bean>
    ...
</beans>

<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0"
           ...
           xmlns:jaxws="http://cxf.apache.org/blueprint/jaxws"
           xmlns:cxf="http://cxf.apache.org/blueprint/core"
           ...
>
    <!-- Create a client proxy, with load balancing enabled -->
    <jaxws:client id="ClientProxyBeanID"
        address="http://dummyaddress"
        serviceClass="SEI">
        <jaxws:features>
            <ref component-id="fabricLoadBalancerFeature" />
        </jaxws:features>
    </jaxws:client>
    ...
    <reference id="org.linkedin.zookeeper.client.IZKClient"
               interface="org.linkedin.zookeeper.client.IZKClient" />

    <!-- Create the Fabric load balancer feature -->
    <bean id="fabricLoadBalancerFeature"
          class="org.fusesource.fabric.cxf.FabricLoadBalancerFeature">
        <property name="zkClient" ref="org.linkedin.zookeeper.client.IZKClient" />
        <property name="fabricPath" value="ZKPath" />
    </bean>
    ...
</blueprint>

// Java
package org.fusesource.fabric.demo.cxf.client;

import org.apache.cxf.feature.AbstractFeature;
import org.apache.cxf.frontend.ClientProxyFactoryBean;
import org.apache.cxf.jaxws.JaxWsProxyFactoryBean;
import org.fusesource.fabric.cxf.FabricLoadBalancerFeature;
import org.fusesource.fabric.demo.cxf.Hello;

import java.util.ArrayList;
import java.util.List;

public class Client {
    
    private Hello hello;

    public void initializeHelloProxy() {
        // The feature will try to create a zookeeper client itself
        // by checking the system property of zookeeper.url
        FabricLoadBalancerFeature feature = new FabricLoadBalancerFeature();
        // Feature will use this path to locate the service
        feature.setFabricPath("demo/lb");

        ClientProxyFactoryBean clientFactory = new JaxWsProxyFactoryBean();
        clientFactory.setServiceClass(ClientProxyFactoryBean.class);
        // The address is not the actual address that the client will access
        clientFactory.setAddress("http://dummyaddress");

        List<AbstractFeature> features = new ArrayList<AbstractFeature>();
        features.add(feature);
        // we need to setup the feature on the client factory
        clientFactory.setFeatures(features);

        // Create the proxy of Hello
        hello = clientFactory.create(Hello.class);
    }
    
    public static void main(String args[]) {
        initializeHelloProxy();
        ...
    }
}