Flume NG源码分析（六）应用程序使用的RpcClient设计

最新推荐文章于 2025-02-13 07:30:00 发布

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最新推荐文章于 2025-02-13 07:30:00 发布

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分类专栏： Flume NG Java Flume NG源码分析文章标签： Flume NG

本文链接：https://blog.youkuaiyun.com/ITer_ZC/article/details/46536315

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上一篇Flume NG源码分析（五）使用ThriftSource通过RPC方式收集日志介绍了ThriftSource利用Thrfit服务ThriftSourceProtocol来收集日志。这篇说说flume-ng-sdk中提供给应用层序使用的RpcClient的设计和实现。继续使用ThriftRpcClient来作例子。

先看看ThriftSourceProtocol提供的原生的客户端，它是Thrfit通过flume.thrift文件定义的Thrfit服务默认生成。这个原生的Client提供了网络传输和协议编解码等RPC客户端的基本功能。关于Thrift客户端可以参考这篇Thrift源码分析（三）-- IDL和生成代码分析

public static class Client extends org.apache.thrift.TServiceClient implements Iface {
    public static class Factory implements org.apache.thrift.TServiceClientFactory<Client> {
      public Factory() {}
      public Client getClient(org.apache.thrift.protocol.TProtocol prot) {
        return new Client(prot);
      }
      public Client getClient(org.apache.thrift.protocol.TProtocol iprot, org.apache.thrift.protocol.TProtocol oprot) {
        return new Client(iprot, oprot);
      }
    }

    public Client(org.apache.thrift.protocol.TProtocol prot)
    {
      super(prot, prot);
    }

    public Client(org.apache.thrift.protocol.TProtocol iprot, org.apache.thrift.protocol.TProtocol oprot) {
      super(iprot, oprot);
    }

    public Status append(ThriftFlumeEvent event) throws org.apache.thrift.TException
    {
      send_append(event);
      return recv_append();
    }

    public void send_append(ThriftFlumeEvent event) throws org.apache.thrift.TException
    {
      append_args args = new append_args();
      args.setEvent(event);
      sendBase("append", args);
    }

    public Status recv_append() throws org.apache.thrift.TException
    {
      append_result result = new append_result();
      receiveBase(result, "append");
      if (result.isSetSuccess()) {
        return result.success;
      }
      throw new org.apache.thrift.TApplicationException(org.apache.thrift.TApplicationException.MISSING_RESULT, "append failed: unknown result");
    }

    public Status appendBatch(List<ThriftFlumeEvent> events) throws org.apache.thrift.TException
    {
      send_appendBatch(events);
      return recv_appendBatch();
    }

    public void send_appendBatch(List<ThriftFlumeEvent> events) throws org.apache.thrift.TException
    {
      appendBatch_args args = new appendBatch_args();
      args.setEvents(events);
      sendBase("appendBatch", args);
    }

    public Status recv_appendBatch() throws org.apache.thrift.TException
    {
      appendBatch_result result = new appendBatch_result();
      receiveBase(result, "appendBatch");
      if (result.isSetSuccess()) {
        return result.success;
      }
      throw new org.apache.thrift.TApplicationException(org.apache.thrift.TApplicationException.MISSING_RESULT, "appendBatch failed: unknown result");
    }

  }

来看看Flume NG是如何封装Thrift客户端的。Flume NG支持Avro，Thrfit等多种RPC实现，它的RpcClient层次结构如下

RpcClient接口定义了给应用程序使用的RPC客户端的基本功能

public interface RpcClient {


  public int getBatchSize();

  
  public void append(Event event) throws EventDeliveryException;

  
  public void appendBatch(List<Event> events) throws
      EventDeliveryException;

  public boolean isActive();

  
  public void close() throws FlumeException;

}

AbstractRpcClient抽象类实现了RPCClient接口，提供了getBatchSize的默认实现，并增加了configure接口来支持配置