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。
扩展接口
org.apache.dubbo.rpc.cluster.Cluster
扩展配置
<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" />
已知扩展
org.apache.dubbo.rpc.cluster.support.wrapper.MockClusterWrapper
org.apache.dubbo.rpc.cluster.support.FailoverCluster
org.apache.dubbo.rpc.cluster.support.FailfastCluster
org.apache.dubbo.rpc.cluster.support.FailsafeCluster
org.apache.dubbo.rpc.cluster.support.FailbackCluster
org.apache.dubbo.rpc.cluster.support.ForkingCluster
org.apache.dubbo.rpc.cluster.support.AvailableCluster
org.apache.dubbo.rpc.cluster.support.MergeableCluster
org.apache.dubbo.rpc.cluster.support.BroadcastCluster
org.apache.dubbo.rpc.cluster.support.registry.ZoneAwareCluster
扩展示例
Maven 项目结构:
src
|-main
|-java
|-com
|-xxx
|-XxxCluster.java (实现Cluster接口)
|-resources
|-META-INF
|-dubbo
|-org.apache.dubbo.rpc.cluster.Cluster (纯文本文件,内容为:xxx=com.xxx.XxxCluster)
XxxCluster.java:
package com.xxx;
import org.apache.dubbo.rpc.cluster.Cluster;
import org.apache.dubbo.rpc.cluster.support.AbstractClusterInvoker;
import org.apache.dubbo.rpc.cluster.Directory;
import org.apache.dubbo.rpc.cluster.LoadBalance;
import org.apache.dubbo.rpc.Invoker;
import org.apache.dubbo.rpc.Invocation;
import org.apache.dubbo.rpc.Result;
import org.apache.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/org.apache.dubbo.rpc.cluster.Cluster:
xxx=com.xxx.XxxCluster
下一节:从多个服务提供方中选择一个进行调用。