Hadoop YARN REST Client 详解

1. 介绍

Hadoop YARN（Yet Another Resource Negotiator）是一个用于大规模数据处理的分布式计算框架。而YARN REST客户端是一种可以通过HTTP协议与YARN REST API进行交互的工具，通过REST客户端，用户可以方便地管理YARN资源、提交作业等操作。

在本文中，我们将介绍如何使用Hadoop YARN REST客户端来与YARN集群进行交互，并给出相应的代码示例。

2. YARN REST客户端的基本功能

YARN REST客户端主要提供以下功能：

  • 查询集群信息
  • 提交作业
  • 查询作业状态
  • 杀死作业
  • 查询应用程序信息等

通过YARN REST客户端，用户可以使用简单的HTTP请求来完成上述操作，方便快捷。

3. 使用YARN REST客户端的步骤

步骤一：创建YARN REST客户端

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.yarn.conf.YarnConfiguration;
import org.apache.hadoop.yarn.client.api.YarnClient;
import org.apache.hadoop.yarn.client.api.YarnClientFactory;
import org.apache.hadoop.yarn.client.api.YarnClientService;

Configuration conf = new YarnConfiguration();
YarnClient yarnClient = YarnClientFactory.createYarnClient();
yarnClient.init(conf);
yarnClient.start();

步骤二：查询集群信息

import org.apache.hadoop.yarn.api.records.YarnClusterMetrics;
import org.apache.hadoop.yarn.exceptions.YarnException;
import org.apache.hadoop.yarn.util.resource.Resources;
import java.io.IOException;

try {
    YarnClusterMetrics clusterMetrics = yarnClient.getYarnClusterMetrics();
    System.out.println("Total Nodes: " + clusterMetrics.getNumNodeManagers());
    System.out.println("Total Virtual Cores: " + clusterMetrics.getTotalVirtualCores());
    System.out.println("Total Memory: " + Resources.formatSize(clusterMetrics.getTotalMB()));
} catch (YarnException | IOException e) {
    e.printStackTrace();
}

步骤三：提交作业

import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
import org.apache.hadoop.yarn.api.records.Priority;
import org.apache.hadoop.yarn.api.records.Resource;
import org.apache.hadoop.yarn.client.api.YarnClientApplication;

YarnClientApplication app = yarnClient.createApplication();

ApplicationSubmissionContext appContext = app.getApplicationSubmissionContext();
appContext.setApplicationName("Test Application");
appContext.setResource(Resource.newInstance(1024, 1));
appContext.setPriority(Priority.newInstance(0));

ApplicationId appId = appContext.getApplicationId();
yarnClient.submitApplication(appContext);

4. 类图

classDiagram
    YarnClient --> Configuration
    YarnClient --> YarnClusterMetrics
    YarnClient --> YarnClientFactory
    YarnClient --> YarnClientService
    YarnClientFactory --> YarnClient
    YarnConfiguration --> Configuration

5. 序列图

sequenceDiagram
    participant Client
    participant YarnClient
    participant YarnClusterMetrics
    participant YarnClientFactory

    Client->>YarnClient: 创建YarnClient
    Client->>YarnClient: 初始化和启动YarnClient
    Client->>YarnClient: 查询集群信息
    YarnClient->>YarnClusterMetrics: 获取YarnClusterMetrics
    YarnClient-->>Client: 返回集群信息

6. 结论

通过本文，我们了解了Hadoop YARN REST客户端的基本功能和使用方法。通过YARN REST客户端，用户可以方便地管理YARN资源、提交作业等操作，提高了大规模数据处理的效率和便利性。希望本文对您有所帮助！