Hbase 客户端批量写入数据

hbase新版本中引入了 BufferedMutator，可以提供更加高效清晰的写操作。

org.apache.hadoop.hbase.client.BufferedMutator主要用来对HBase的单个表进行操作。它和Put类的作用差不多，但是主要用来实现批量的异步写操作。
可以从Connection的实例中获取BufferedMutator的实例。在使用完成后需要调用close()方法关闭连接。对BufferedMutator进行配置需要通过BufferedMutatorParams完成。
BufferedMutator接收发送来的Put数据后，会根据某些因素（比如接收的Put数据的总量）启发式地执行Batch Put操作，且会异步的提交Batch Put请求。
BufferedMutator也可以用在一些特殊的情况上。多线程作业的每个线程将会拥有一个独立的BufferedMutator对象。
一个独立的BufferedMutator也可以用在大容量的在线系统上来执行批量Put操作，但是这时需要注意一些极端情况比如JVM异常或机器故障，此时有可能造成数据丢失。
官方源码路径：https://github.com/apache/hbase/blob/master/hbase-examples/src/main/java/org/apache/hadoop/hbase/client/example/BufferedMutatorExample.java

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package org.apache.hadoop.hbase.client.example;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.BufferedMutator;
import org.apache.hadoop.hbase.client.BufferedMutatorParams;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.ConnectionFactory;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.RetriesExhaustedWithDetailsException;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * An example of using the {@link BufferedMutator} interface.
 */
@InterfaceAudience.Private
public class BufferedMutatorExample extends Configured implements Tool {

  private static final Logger LOG = LoggerFactory.getLogger(BufferedMutatorExample.class);

  private static final int POOL_SIZE = 10;
  private static final int TASK_COUNT = 100;
  private static final TableName TABLE = TableName.valueOf("foo");
  private static final byte[] FAMILY = Bytes.toBytes("f");

  @Override
  public int run(String[] args) throws InterruptedException, ExecutionException, TimeoutException {

    /** a callback invoked when an asynchronous write fails. */
    final BufferedMutator.ExceptionListener listener = new BufferedMutator.ExceptionListener() {
      @Override
      public void onException(RetriesExhaustedWithDetailsException e, BufferedMutator mutator) {
        for (int i = 0; i < e.getNumExceptions(); i++) {
          LOG.info("Failed to sent put " + e.getRow(i) + ".");
        }
      }
    };
    BufferedMutatorParams params = new BufferedMutatorParams(TABLE)
        .listener(listener);

    //
    // step 1: create a single Connection and a BufferedMutator, shared by all worker threads.
    //
    try (final Connection conn = ConnectionFactory.createConnection(getConf());
         final BufferedMutator mutator = conn.getBufferedMutator(params)) {

      /** worker pool that operates on BufferedTable instances */
      final ExecutorService workerPool = Executors.newFixedThreadPool(POOL_SIZE);
      List<Future<Void>> futures = new ArrayList<>(TASK_COUNT);

      for (int i = 0; i < TASK_COUNT; i++) {
        futures.add(workerPool.submit(new Callable<Void>() {
          @Override
          public Void call() throws Exception {
            //
            // step 2: each worker sends edits to the shared BufferedMutator instance. They all use
            // the same backing buffer, call-back "listener", and RPC executor pool.
            //
            Put p = new Put(Bytes.toBytes("someRow"));
            p.addColumn(FAMILY, Bytes.toBytes("someQualifier"), Bytes.toBytes("some value"));
            mutator.mutate(p);
            // do work... maybe you want to call mutator.flush() after many edits to ensure any of
            // this worker's edits are sent before exiting the Callable
            return null;
          }
        }));
      }

      //
      // step 3: clean up the worker pool, shut down.
      //
      for (Future<Void> f : futures) {
        f.get(5, TimeUnit.MINUTES);
      }
      workerPool.shutdown();
    } catch (IOException e) {
      // exception while creating/destroying Connection or BufferedMutator
      LOG.info("exception while creating/destroying Connection or BufferedMutator", e);
    } // BufferedMutator.close() ensures all work is flushed. Could be the custom listener is
      // invoked from here.
    return 0;
  }

  public static void main(String[] args) throws Exception {
    ToolRunner.run(new BufferedMutatorExample(), args);
  }
}