Cluster Expansion

Expansion Description

When there are multiple service providers, organize multiple service providers into a cluster and pretend to be one provider.

Extension ports

org.apache.dubbo.rpc.cluster.Cluster

Extended configuration

<dubbo:protocol cluster="xxx" />
<!-- Default value configuration, if <dubbo:protocol> is not configured with cluster, use this configuration -->
<dubbo:provider cluster="xxx" />

Known extensions

  • 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

Extended example

Maven project structure:

src
 |-main
    |-java
        |-com
            |-xxx
                |-XxxCluster.java (implements the Cluster interface)
    |-resources
        |-META-INF
            |-dubbo
                |-org.apache.dubbo.rpc.cluster.Cluster (plain text file, content: 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

Last modified January 2, 2023: Enhance en docs (#1798) (95a9f4f6c)