org.apache.hadoop.hbase.util.ModifyRegionUtils.java Source code

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/**
 *
 * 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.util;

import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletionService;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorCompletionService;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.regionserver.HRegion;
import org.apache.hadoop.hbase.master.AssignmentManager;

/**
 * Utility methods for interacting with the regions.
 */
@InterfaceAudience.Private
public abstract class ModifyRegionUtils {
    private static final Log LOG = LogFactory.getLog(ModifyRegionUtils.class);

    private ModifyRegionUtils() {
    }

    public interface RegionFillTask {
        void fillRegion(final HRegion region) throws IOException;
    }

    public interface RegionEditTask {
        void editRegion(final HRegionInfo region) throws IOException;
    }

    /**
     * Create new set of regions on the specified file-system.
     * NOTE: that you should add the regions to hbase:meta after this operation.
     *
     * @param conf {@link Configuration}
     * @param rootDir Root directory for HBase instance
     * @param hTableDescriptor description of the table
     * @param newRegions {@link HRegionInfo} that describes the regions to create
     * @throws IOException
     */
    public static List<HRegionInfo> createRegions(final Configuration conf, final Path rootDir,
            final HTableDescriptor hTableDescriptor, final HRegionInfo[] newRegions) throws IOException {
        return createRegions(conf, rootDir, hTableDescriptor, newRegions, null);
    }

    /**
     * Create new set of regions on the specified file-system.
     * NOTE: that you should add the regions to hbase:meta after this operation.
     *
     * @param conf {@link Configuration}
     * @param rootDir Root directory for HBase instance
     * @param hTableDescriptor description of the table
     * @param newRegions {@link HRegionInfo} that describes the regions to create
     * @param task {@link RegionFillTask} custom code to populate region after creation
     * @throws IOException
     */
    public static List<HRegionInfo> createRegions(final Configuration conf, final Path rootDir,
            final HTableDescriptor hTableDescriptor, final HRegionInfo[] newRegions, final RegionFillTask task)
            throws IOException {

        Path tableDir = FSUtils.getTableDir(rootDir, hTableDescriptor.getTableName());
        return createRegions(conf, rootDir, tableDir, hTableDescriptor, newRegions, task);
    }

    /**
     * Create new set of regions on the specified file-system.
     * NOTE: that you should add the regions to hbase:meta after this operation.
     *
     * @param conf {@link Configuration}
     * @param rootDir Root directory for HBase instance
     * @param tableDir table directory
     * @param hTableDescriptor description of the table
     * @param newRegions {@link HRegionInfo} that describes the regions to create
     * @param task {@link RegionFillTask} custom code to populate region after creation
     * @throws IOException
     */
    public static List<HRegionInfo> createRegions(final Configuration conf, final Path rootDir, final Path tableDir,
            final HTableDescriptor hTableDescriptor, final HRegionInfo[] newRegions, final RegionFillTask task)
            throws IOException {
        if (newRegions == null)
            return null;
        int regionNumber = newRegions.length;
        ThreadPoolExecutor exec = getRegionOpenAndInitThreadPool(conf,
                "RegionOpenAndInitThread-" + hTableDescriptor.getTableName(), regionNumber);
        try {
            return createRegions(exec, conf, rootDir, tableDir, hTableDescriptor, newRegions, task);
        } finally {
            exec.shutdownNow();
        }
    }

    /**
     * Create new set of regions on the specified file-system.
     * NOTE: that you should add the regions to hbase:meta after this operation.
     *
     * @param exec Thread Pool Executor
     * @param conf {@link Configuration}
     * @param rootDir Root directory for HBase instance
     * @param tableDir table directory
     * @param hTableDescriptor description of the table
     * @param newRegions {@link HRegionInfo} that describes the regions to create
     * @param task {@link RegionFillTask} custom code to populate region after creation
     * @throws IOException
     */
    public static List<HRegionInfo> createRegions(final ThreadPoolExecutor exec, final Configuration conf,
            final Path rootDir, final Path tableDir, final HTableDescriptor hTableDescriptor,
            final HRegionInfo[] newRegions, final RegionFillTask task) throws IOException {
        if (newRegions == null)
            return null;
        int regionNumber = newRegions.length;
        CompletionService<HRegionInfo> completionService = new ExecutorCompletionService<HRegionInfo>(exec);
        List<HRegionInfo> regionInfos = new ArrayList<HRegionInfo>();
        for (final HRegionInfo newRegion : newRegions) {
            completionService.submit(new Callable<HRegionInfo>() {
                @Override
                public HRegionInfo call() throws IOException {
                    return createRegion(conf, rootDir, tableDir, hTableDescriptor, newRegion, task);
                }
            });
        }
        try {
            // wait for all regions to finish creation
            for (int i = 0; i < regionNumber; i++) {
                Future<HRegionInfo> future = completionService.take();
                HRegionInfo regionInfo = future.get();
                regionInfos.add(regionInfo);
            }
        } catch (InterruptedException e) {
            LOG.error("Caught " + e + " during region creation");
            throw new InterruptedIOException(e.getMessage());
        } catch (ExecutionException e) {
            throw new IOException(e);
        }
        return regionInfos;
    }

    /**
     * Create new set of regions on the specified file-system.
     * @param conf {@link Configuration}
     * @param rootDir Root directory for HBase instance
     * @param tableDir table directory
     * @param hTableDescriptor description of the table
     * @param newRegion {@link HRegionInfo} that describes the region to create
     * @param task {@link RegionFillTask} custom code to populate region after creation
     * @throws IOException
     */
    public static HRegionInfo createRegion(final Configuration conf, final Path rootDir, final Path tableDir,
            final HTableDescriptor hTableDescriptor, final HRegionInfo newRegion, final RegionFillTask task)
            throws IOException {
        // 1. Create HRegion
        HRegion region = HRegion.createHRegion(newRegion, rootDir, tableDir, conf, hTableDescriptor, null, false,
                true);
        try {
            // 2. Custom user code to interact with the created region
            if (task != null) {
                task.fillRegion(region);
            }
        } finally {
            // 3. Close the new region to flush to disk. Close log file too.
            region.close();
        }
        return region.getRegionInfo();
    }

    /**
     * Execute the task on the specified set of regions.
     *
     * @param exec Thread Pool Executor
     * @param regions {@link HRegionInfo} that describes the regions to edit
     * @param task {@link RegionFillTask} custom code to edit the region
     * @throws IOException
     */
    public static void editRegions(final ThreadPoolExecutor exec, final Collection<HRegionInfo> regions,
            final RegionEditTask task) throws IOException {
        final ExecutorCompletionService<Void> completionService = new ExecutorCompletionService<Void>(exec);
        for (final HRegionInfo hri : regions) {
            completionService.submit(new Callable<Void>() {
                @Override
                public Void call() throws IOException {
                    task.editRegion(hri);
                    return null;
                }
            });
        }

        try {
            for (HRegionInfo hri : regions) {
                completionService.take().get();
            }
        } catch (InterruptedException e) {
            throw new InterruptedIOException(e.getMessage());
        } catch (ExecutionException e) {
            IOException ex = new IOException();
            ex.initCause(e.getCause());
            throw ex;
        }
    }

    /*
     * used by createRegions() to get the thread pool executor based on the
     * "hbase.hregion.open.and.init.threads.max" property.
     */
    static ThreadPoolExecutor getRegionOpenAndInitThreadPool(final Configuration conf,
            final String threadNamePrefix, int regionNumber) {
        int maxThreads = Math.min(regionNumber, conf.getInt("hbase.hregion.open.and.init.threads.max", 10));
        ThreadPoolExecutor regionOpenAndInitThreadPool = Threads.getBoundedCachedThreadPool(maxThreads, 30L,
                TimeUnit.SECONDS, new ThreadFactory() {
                    private int count = 1;

                    @Override
                    public Thread newThread(Runnable r) {
                        Thread t = new Thread(r, threadNamePrefix + "-" + count++);
                        return t;
                    }
                });
        return regionOpenAndInitThreadPool;
    }

    /**
     * Triggers a bulk assignment of the specified regions
     *
     * @param assignmentManager the Assignment Manger
     * @param regionInfos the list of regions to assign
     * @throws IOException if an error occurred during the assignment
     */
    public static void assignRegions(final AssignmentManager assignmentManager, final List<HRegionInfo> regionInfos)
            throws IOException {
        try {
            assignmentManager.getRegionStates().createRegionStates(regionInfos);
            assignmentManager.assign(regionInfos);
        } catch (InterruptedException e) {
            LOG.error("Caught " + e + " during round-robin assignment");
            InterruptedIOException ie = new InterruptedIOException(e.getMessage());
            ie.initCause(e);
            throw ie;
        }
    }
}