Samza的ApplicationMaster

当Samza ApplicationMaster启动时,它做以下的事情:

  1. 通过STREAMING_CONFIG环境变量从YARN获取配置信息(configuration)
  2. 在随机端口上 启动一个JMX server
  3. 实例化一个metrics registry和reporter来追踪计量信息
  4. 将AM向YARN的RM注册
  5. 使用每个stream的PartitionManager来获取总共的partition数量
  6. 从Samza的job configuration里获取总的container数量
  7. 将partition分给container(在Samza AM的dashboard里,称为Task Group)
  8. 为每个container向YARN发送一个ResourceRequest
  9. 每秒向YARN RM poll一次,检查allocated and released containers
SamzaAppMaster的实现
 
并不是提交AppMaster,只是向RM注册这个AppMaster。因为此时,AppMaster已经启动了。
1.在SamzaAppMasterLifecycle对象的onInit()方法中,使用amCient.registerApplicationMaster
2    val response = amClient.registerApplicationMaster (host , state.rpcPort, "%s:%d" format (host, state. trackingPort))
 
amClient对象的类:
 
org.apache.hadoop.yarn.client.api.async.AMRMClientAsync<T extends org.apache.hadoop.yarn.client.api.AMRMClient.ContainerRequest>
 

AMRMClientAsync handles communication with the ResourceManager and provides asynchronous updates on events such as container allocations and completions. It contains a thread that sends periodic heartbeats to the ResourceManager. It should be used by implementing a CallbackHandler:

 class MyCallbackHandler implements AMRMClientAsync.CallbackHandler {
   public void onContainersAllocated(List<Container> containers) {
     [run tasks on the containers]
   }
   
   public void onContainersCompleted(List<ContainerStatus> statuses) {
     [update progress, check whether app is done]
   }
   
   public void onNodesUpdated(List<NodeReport> updated) {}
   
   public void onReboot() {}
 }
 
 
The client‘s lifecycle should be managed similarly to the following:
 AMRMClientAsync asyncClient = 
     createAMRMClientAsync(appAttId, 1000, new MyCallbackhandler());
 asyncClient.init(conf);
 asyncClient.start();
 RegisterApplicationMasterResponse response = asyncClient
    .registerApplicationMaster(appMasterHostname, appMasterRpcPort,
       appMasterTrackingUrl);
 asyncClient.addContainerRequest(containerRequest);
 [... wait for application to complete]
 asyncClient.unregisterApplicationMaster(status, appMsg, trackingUrl);
 asyncClient.stop();
这个类是用来做为一个Client和RM进行通信,并且注册一个用于回调的对象来处理container 的allocation和completion事件。它启动一个线程,周期性地发送hearbeat至ResourceManager

Samza的ApplicationMaster,,5-wow.com

郑重声明:本站内容如果来自互联网及其他传播媒体,其版权均属原媒体及文章作者所有。转载目的在于传递更多信息及用于网络分享,并不代表本站赞同其观点和对其真实性负责,也不构成任何其他建议。