HBase Client JAVA API

/**

 *

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

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);

  }

}