当有多个服务提供方时,将多个服务提供方组织成一个集群,并伪装成一个提供方。
com.alibaba.dubbo.rpc.cluster.Cluster
<dubbo:protocol cluster="xxx" /> <!-- 缺省值配置,如果<dubbo:protocol>没有配置cluster时,使用此配置 --> <dubbo:provider cluster="xxx" />
com.alibaba.dubbo.rpc.cluster.support.FailoverCluster
com.alibaba.dubbo.rpc.cluster.support.FailfastCluster
com.alibaba.dubbo.rpc.cluster.support.FailsafeCluster
com.alibaba.dubbo.rpc.cluster.support.FailbackCluster
com.alibaba.dubbo.rpc.cluster.support.ForkingCluster
com.alibaba.dubbo.rpc.cluster.support.AvailableCluster
Maven 项目结构:
src |-main |-java |-com |-xxx |-XxxCluster.java (实现Cluster接口) |-resources |-META-INF |-dubbo |-com.alibaba.dubbo.rpc.cluster.Cluster (纯文本文件,内容为:xxx=com.xxx.XxxCluster)
XxxCluster.java:
package com.xxx; import com.alibaba.dubbo.rpc.cluster.Cluster; import com.alibaba.dubbo.rpc.cluster.support.AbstractClusterInvoker; import com.alibaba.dubbo.rpc.cluster.Directory; import com.alibaba.dubbo.rpc.cluster.LoadBalance; import com.alibaba.dubbo.rpc.Invoker; import com.alibaba.dubbo.rpc.Invocation; import com.alibaba.dubbo.rpc.Result; import com.alibaba.dubbo.rpc.RpcException; public class XxxCluster implements Cluster { public <T> Invoker<T> merge(Directory<T> directory) throws RpcException { return new AbstractClusterInvoker<T>(directory) { public Result doInvoke(Invocation invocation, List<Invoker<T>> invokers, LoadBalance loadbalance) throws RpcException { // ... } }; } }
META-INF/dubbo/com.alibaba.dubbo.rpc.cluster.Cluster:
xxx=com.xxx.XxxCluster