HadoopRPC源码阅读交互协议

package org.apache.hadoop.ipc;import java.io.IOException;/*** Superclass of all protocols that use Hadoop RPC.* Subclasses of this interface are also supposed to have* a static final long versionID field.*/
public interface VersionedProtocol {/*** Return protocol version corresponding to protocol interface.* &＃64;param protocol The classname of the protocol interface* &＃64;param clientVersion The version of the protocol that the client speaks* &＃64;return the version that the server will speak* &＃64;throws IOException if any IO error occurs*/public long getProtocolVersion(String protocol,long clientVersion) throws IOException;/*** Return protocol version corresponding to protocol interface.* &＃64;param protocol The classname of the protocol interface* &＃64;param clientVersion The version of the protocol that the client speaks* &＃64;param clientMethodsHash the hashcode of client protocol methods* &＃64;return the server protocol signature containing its version and* a list of its supported methods* &＃64;see ProtocolSignature#getProtocolSignature(VersionedProtocol, String, * long, int) for a default implementation*/public ProtocolSignature getProtocolSignature(String protocol, long clientVersion,int clientMethodsHash) throws IOException;
}

ClientDatanodeProtocol &＃xff1a;一个客户端和datanode之间的协议接口&＃xff0c;用于数据块恢复
ClientProtocol &＃xff1a;client与Namenode交互的接口&＃xff0c;所有控制流的请求均在这里&＃xff0c;如&＃xff1a;创建文件、删除文件等&＃xff1b;
DatanodeProtocol : Datanode与Namenode交互的接口&＃xff0c;如心跳、blockreport等&＃xff1b;
NamenodeProtocol &＃xff1a;SecondaryNode与Namenode交互的接口。

InterDatanodeProtocol &＃xff1a;Datanode内部交互的接口&＃xff0c;用来更新block的元数据&＃xff1b;
InnerTrackerProtocol &＃xff1a;TaskTracker与JobTracker交互的接口&＃xff0c;功能与DatanodeProtocol相似&＃xff1b;//在hadoop2.6中找不到
JobSubmissionProtocol &＃xff1a;JobClient与JobTracker交互的接口&＃xff0c;用来提交Job、获得Job等与Job相关的操作&＃xff1b;//在hadoop2.6中找不到
TaskUmbilicalProtocol &＃xff1a;Task中子进程与母进程交互的接口&＃xff0c;子进程即map、reduce等操作&＃xff0c;母进程即TaskTracker&＃xff0c;该接口可以回报子进程的运行状态&＃xff08;词汇扫盲: umbilical 脐带的, 关系亲密的&＃xff09; 。