YARN-RPC-ApplicationClientProtocol源码

一. ApplicationClientProtocol

ApplicationClientProtocol接口继承ApplicationBaseProtocol接口
ApplicationBaseProtocol接口的内容

1.1 ApplicationBaseProtocol

客户端和RM/ApplicationHistoryServer之间的协议，获取信息/applications/application attempts/containers，方法有：

getApplicationReport
getApplications
getApplicationAttemptReport
getApplicationAttempts
getContainerReport
getContainers
getDelegationToken
renewDelegationToken
cancelDelegationToken

以getApplicationReport说明如下：

public GetApplicationReportResponse getApplicationReport(
      GetApplicationReportRequest request) throws YarnException, IOException;

客户端通过GetApplicationReportRequest提供ApplicationId；
在安全模式，在接收request之前，RM/AHS验证到应用的访问权限/队列等。
RM/AHS返回GetApplicationReportResponse，含有ApplicationReport；
如果没有应用的访问权限，有一些标志位做相应的设置；

public GetApplicationsResponse
      getApplications(GetApplicationsRequest request) throws YarnException,
          IOException;

GetApplicationsRequest中定义了一些filter，进行application匹配，
RM或AHS响应一个GetApplicationsResponse，包含ApplicationReport，也会验证访问权限；

1.2 ApplicationClientProtocol

client和RM之间发送/停止jobs，或者获取应用、集群信息、节点、队列和ACL
ApplicationClientProtocol继承自ApplicationBaseProtocol

#获取新的ApplicationId，资源信息等
getNewApplication	
#提交application,client需要提交队列、运行ApplicationMaster的资源，ContainerLaunchContext去launch ApplicationMaster
submitApplication
forceKillApplication
getClusterMetrics
getClusterNodes
getQueueInfo
getQueueUserAcls
moveApplicationAcrossQueues
submitReservation
updateReservation
deleteReservation

#获取NodeToLabels
getNodeToLabels
getClusterNodeLabels

Label based scheduling：http://dongxicheng.org/mapreduce-nextgen/hadoop-yarn-label-based-scheduling/