org.apache.hadoop.hbase.client.TestClientNoCluster.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.client;

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.IOException;
import java.net.SocketTimeoutException;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;
import java.util.SortedMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

import com.google.protobuf.HBaseZeroCopyByteString;
import org.apache.commons.lang.NotImplementedException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.RegionTooBusyException;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.SmallTests;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.protobuf.generated.CellProtos;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.BulkLoadHFileRequest;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.BulkLoadHFileResponse;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ClientService;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ClientService.BlockingInterface;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.CoprocessorServiceRequest;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.CoprocessorServiceResponse;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.GetRequest;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.GetResponse;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MultiRequest;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MultiResponse;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutateRequest;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.MutateResponse;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.RegionAction;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.RegionActionResult;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ResultOrException;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanRequest;
import org.apache.hadoop.hbase.protobuf.generated.ClientProtos.ScanResponse;
import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.RegionSpecifier.RegionSpecifierType;
import org.apache.hadoop.hbase.regionserver.RegionServerStoppedException;
import org.apache.hadoop.hbase.security.User;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.Pair;
import org.apache.hadoop.hbase.util.Threads;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.mockito.Mockito;

import com.google.common.base.Stopwatch;
import com.google.protobuf.ByteString;
import com.google.protobuf.RpcController;
import com.google.protobuf.ServiceException;

/**
 * Test client behavior w/o setting up a cluster.
 * Mock up cluster emissions.
 */
@Category(SmallTests.class)
public class TestClientNoCluster extends Configured implements Tool {
    private static final Log LOG = LogFactory.getLog(TestClientNoCluster.class);
    private Configuration conf;
    public static final ServerName META_SERVERNAME = ServerName.valueOf("meta.example.org", 16010, 12345);

    @Before
    public void setUp() throws Exception {
        this.conf = HBaseConfiguration.create();
        // Run my HConnection overrides.  Use my little HConnectionImplementation below which
        // allows me insert mocks and also use my Registry below rather than the default zk based
        // one so tests run faster and don't have zk dependency.
        this.conf.set("hbase.client.registry.impl", SimpleRegistry.class.getName());
    }

    /**
     * Simple cluster registry inserted in place of our usual zookeeper based one.
     */
    static class SimpleRegistry implements Registry {
        final ServerName META_HOST = META_SERVERNAME;

        @Override
        public void init(HConnection connection) {
        }

        @Override
        public HRegionLocation getMetaRegionLocation() throws IOException {
            return new HRegionLocation(HRegionInfo.FIRST_META_REGIONINFO, META_HOST);
        }

        @Override
        public String getClusterId() {
            return HConstants.CLUSTER_ID_DEFAULT;
        }

        @Override
        public boolean isTableOnlineState(TableName tableName, boolean enabled) throws IOException {
            return enabled;
        }

        @Override
        public int getCurrentNrHRS() throws IOException {
            return 1;
        }
    }

    /**
     * Remove the @Ignore to try out timeout and retry asettings
     * @throws IOException
     */
    @Ignore
    @Test
    public void testTimeoutAndRetries() throws IOException {
        Configuration localConfig = HBaseConfiguration.create(this.conf);
        // This override mocks up our exists/get call to throw a RegionServerStoppedException.
        localConfig.set("hbase.client.connection.impl", RpcTimeoutConnection.class.getName());
        HTable table = new HTable(localConfig, TableName.META_TABLE_NAME);
        Throwable t = null;
        LOG.info("Start");
        try {
            // An exists call turns into a get w/ a flag.
            table.exists(new Get(Bytes.toBytes("abc")));
        } catch (SocketTimeoutException e) {
            // I expect this exception.
            LOG.info("Got expected exception", e);
            t = e;
        } catch (RetriesExhaustedException e) {
            // This is the old, unwanted behavior.  If we get here FAIL!!!
            fail();
        } finally {
            table.close();
        }
        LOG.info("Stop");
        assertTrue(t != null);
    }

    /**
     * Test that operation timeout prevails over rpc default timeout and retries, etc.
     * @throws IOException
     */
    @Test
    public void testRocTimeout() throws IOException {
        Configuration localConfig = HBaseConfiguration.create(this.conf);
        // This override mocks up our exists/get call to throw a RegionServerStoppedException.
        localConfig.set("hbase.client.connection.impl", RpcTimeoutConnection.class.getName());
        int pause = 10;
        localConfig.setInt("hbase.client.pause", pause);
        localConfig.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 10);
        // Set the operation timeout to be < the pause.  Expectation is that after first pause, we will
        // fail out of the rpc because the rpc timeout will have been set to the operation tiemout
        // and it has expired.  Otherwise, if this functionality is broke, all retries will be run --
        // all ten of them -- and we'll get the RetriesExhaustedException exception.
        localConfig.setInt(HConstants.HBASE_CLIENT_META_OPERATION_TIMEOUT, pause - 1);
        HTable table = new HTable(localConfig, TableName.META_TABLE_NAME);
        Throwable t = null;
        try {
            // An exists call turns into a get w/ a flag.
            table.exists(new Get(Bytes.toBytes("abc")));
        } catch (SocketTimeoutException e) {
            // I expect this exception.
            LOG.info("Got expected exception", e);
            t = e;
        } catch (RetriesExhaustedException e) {
            // This is the old, unwanted behavior.  If we get here FAIL!!!
            fail();
        } finally {
            table.close();
        }
        assertTrue(t != null);
    }

    @Test
    public void testDoNotRetryMetaScanner() throws IOException {
        this.conf.set("hbase.client.connection.impl", RegionServerStoppedOnScannerOpenConnection.class.getName());
        MetaScanner.metaScan(this.conf, null);
    }

    @Test
    public void testDoNotRetryOnScanNext() throws IOException {
        this.conf.set("hbase.client.connection.impl", RegionServerStoppedOnScannerOpenConnection.class.getName());
        // Go against meta else we will try to find first region for the table on construction which
        // means we'll have to do a bunch more mocking.  Tests that go against meta only should be
        // good for a bit of testing.
        HTable table = new HTable(this.conf, TableName.META_TABLE_NAME);
        ResultScanner scanner = table.getScanner(HConstants.CATALOG_FAMILY);
        try {
            Result result = null;
            while ((result = scanner.next()) != null) {
                LOG.info(result);
            }
        } finally {
            scanner.close();
            table.close();
        }
    }

    @Test
    public void testRegionServerStoppedOnScannerOpen() throws IOException {
        this.conf.set("hbase.client.connection.impl", RegionServerStoppedOnScannerOpenConnection.class.getName());
        // Go against meta else we will try to find first region for the table on construction which
        // means we'll have to do a bunch more mocking.  Tests that go against meta only should be
        // good for a bit of testing.
        HTable table = new HTable(this.conf, TableName.META_TABLE_NAME);
        ResultScanner scanner = table.getScanner(HConstants.CATALOG_FAMILY);
        try {
            Result result = null;
            while ((result = scanner.next()) != null) {
                LOG.info(result);
            }
        } finally {
            scanner.close();
            table.close();
        }
    }

    /**
     * Override to shutdown going to zookeeper for cluster id and meta location.
     */
    static class ScanOpenNextThenExceptionThenRecoverConnection
            extends ConnectionManager.HConnectionImplementation {
        final ClientService.BlockingInterface stub;

        ScanOpenNextThenExceptionThenRecoverConnection(Configuration conf, boolean managed, ExecutorService pool)
                throws IOException {
            super(conf, managed);
            // Mock up my stub so open scanner returns a scanner id and then on next, we throw
            // exceptions for three times and then after that, we return no more to scan.
            this.stub = Mockito.mock(ClientService.BlockingInterface.class);
            long sid = 12345L;
            try {
                Mockito.when(stub.scan((RpcController) Mockito.any(), (ClientProtos.ScanRequest) Mockito.any()))
                        .thenReturn(ClientProtos.ScanResponse.newBuilder().setScannerId(sid).build())
                        .thenThrow(new ServiceException(new RegionServerStoppedException("From Mockito")))
                        .thenReturn(ClientProtos.ScanResponse.newBuilder().setScannerId(sid).setMoreResults(false)
                                .build());
            } catch (ServiceException e) {
                throw new IOException(e);
            }
        }

        @Override
        public BlockingInterface getClient(ServerName sn) throws IOException {
            return this.stub;
        }
    }

    /**
     * Override to shutdown going to zookeeper for cluster id and meta location.
     */
    static class RegionServerStoppedOnScannerOpenConnection extends ConnectionManager.HConnectionImplementation {
        final ClientService.BlockingInterface stub;

        RegionServerStoppedOnScannerOpenConnection(Configuration conf, boolean managed, ExecutorService pool,
                User user) throws IOException {
            super(conf, managed);
            // Mock up my stub so open scanner returns a scanner id and then on next, we throw
            // exceptions for three times and then after that, we return no more to scan.
            this.stub = Mockito.mock(ClientService.BlockingInterface.class);
            long sid = 12345L;
            try {
                Mockito.when(stub.scan((RpcController) Mockito.any(), (ClientProtos.ScanRequest) Mockito.any()))
                        .thenReturn(ClientProtos.ScanResponse.newBuilder().setScannerId(sid).build())
                        .thenThrow(new ServiceException(new RegionServerStoppedException("From Mockito")))
                        .thenReturn(ClientProtos.ScanResponse.newBuilder().setScannerId(sid).setMoreResults(false)
                                .build());
            } catch (ServiceException e) {
                throw new IOException(e);
            }
        }

        @Override
        public BlockingInterface getClient(ServerName sn) throws IOException {
            return this.stub;
        }
    }

    /**
     * Override to check we are setting rpc timeout right.
     */
    static class RpcTimeoutConnection extends ConnectionManager.HConnectionImplementation {
        final ClientService.BlockingInterface stub;

        RpcTimeoutConnection(Configuration conf, boolean managed, ExecutorService pool, User user)
                throws IOException {
            super(conf, managed);
            // Mock up my stub so an exists call -- which turns into a get -- throws an exception
            this.stub = Mockito.mock(ClientService.BlockingInterface.class);
            try {
                Mockito.when(stub.get((RpcController) Mockito.any(), (ClientProtos.GetRequest) Mockito.any()))
                        .thenThrow(new ServiceException(new RegionServerStoppedException("From Mockito")));
            } catch (ServiceException e) {
                throw new IOException(e);
            }
        }

        @Override
        public BlockingInterface getClient(ServerName sn) throws IOException {
            return this.stub;
        }
    }

    /**
     * Fake many regionservers and many regions on a connection implementation.
     */
    static class ManyServersManyRegionsConnection extends ConnectionManager.HConnectionImplementation {
        // All access should be synchronized
        final Map<ServerName, ClientService.BlockingInterface> serversByClient;

        /**
         * Map of faked-up rows of a 'meta table'.
         */
        final SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta;
        final AtomicLong sequenceids = new AtomicLong(0);
        private final Configuration conf;

        ManyServersManyRegionsConnection(Configuration conf, boolean managed, ExecutorService pool, User user)
                throws IOException {
            super(conf, managed, pool, user);
            int serverCount = conf.getInt("hbase.test.servers", 10);
            this.serversByClient = new HashMap<ServerName, ClientService.BlockingInterface>(serverCount);
            this.meta = makeMeta(Bytes.toBytes(conf.get("hbase.test.tablename", Bytes.toString(BIG_USER_TABLE))),
                    conf.getInt("hbase.test.regions", 100), conf.getLong("hbase.test.namespace.span", 1000),
                    serverCount);
            this.conf = conf;
        }

        @Override
        public ClientService.BlockingInterface getClient(ServerName sn) throws IOException {
            // if (!sn.toString().startsWith("meta")) LOG.info(sn);
            ClientService.BlockingInterface stub = null;
            synchronized (this.serversByClient) {
                stub = this.serversByClient.get(sn);
                if (stub == null) {
                    stub = new FakeServer(this.conf, meta, sequenceids);
                    this.serversByClient.put(sn, stub);
                }
            }
            return stub;
        }
    }

    static MultiResponse doMultiResponse(final SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta,
            final AtomicLong sequenceids, final MultiRequest request) {
        // Make a response to match the request.  Act like there were no failures.
        ClientProtos.MultiResponse.Builder builder = ClientProtos.MultiResponse.newBuilder();
        // Per Region.
        RegionActionResult.Builder regionActionResultBuilder = RegionActionResult.newBuilder();
        ResultOrException.Builder roeBuilder = ResultOrException.newBuilder();
        for (RegionAction regionAction : request.getRegionActionList()) {
            regionActionResultBuilder.clear();
            // Per Action in a Region.
            for (ClientProtos.Action action : regionAction.getActionList()) {
                roeBuilder.clear();
                // Return empty Result and proper index as result.
                roeBuilder.setResult(ClientProtos.Result.getDefaultInstance());
                roeBuilder.setIndex(action.getIndex());
                regionActionResultBuilder.addResultOrException(roeBuilder.build());
            }
            builder.addRegionActionResult(regionActionResultBuilder.build());
        }
        return builder.build();
    }

    /**
     * Fake 'server'.
     * Implements the ClientService responding as though it were a 'server' (presumes a new
     * ClientService.BlockingInterface made per server).
     */
    static class FakeServer implements ClientService.BlockingInterface {
        private AtomicInteger multiInvocationsCount = new AtomicInteger(0);
        private final SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta;
        private final AtomicLong sequenceids;
        private final long multiPause;
        private final int tooManyMultiRequests;

        FakeServer(final Configuration c, final SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta,
                final AtomicLong sequenceids) {
            this.meta = meta;
            this.sequenceids = sequenceids;

            // Pause to simulate the server taking time applying the edits.  This will drive up the
            // number of threads used over in client.
            this.multiPause = c.getLong("hbase.test.multi.pause.when.done", 0);
            this.tooManyMultiRequests = c.getInt("hbase.test.multi.too.many", 3);
        }

        @Override
        public GetResponse get(RpcController controller, GetRequest request) throws ServiceException {
            boolean metaRegion = isMetaRegion(request.getRegion().getValue().toByteArray(),
                    request.getRegion().getType());
            if (!metaRegion) {
                return doGetResponse(request);
            }
            return doMetaGetResponse(meta, request);
        }

        private GetResponse doGetResponse(GetRequest request) {
            ClientProtos.Result.Builder resultBuilder = ClientProtos.Result.newBuilder();
            ByteString row = request.getGet().getRow();
            resultBuilder.addCell(getStartCode(row));
            GetResponse.Builder builder = GetResponse.newBuilder();
            builder.setResult(resultBuilder.build());
            return builder.build();
        }

        @Override
        public MutateResponse mutate(RpcController controller, MutateRequest request) throws ServiceException {
            throw new NotImplementedException();
        }

        @Override
        public ScanResponse scan(RpcController controller, ScanRequest request) throws ServiceException {
            // Presume it is a scan of meta for now. Not all scans provide a region spec expecting
            // the server to keep reference by scannerid.  TODO.
            return doMetaScanResponse(meta, sequenceids, request);
        }

        @Override
        public BulkLoadHFileResponse bulkLoadHFile(RpcController controller, BulkLoadHFileRequest request)
                throws ServiceException {
            throw new NotImplementedException();
        }

        @Override
        public CoprocessorServiceResponse execService(RpcController controller, CoprocessorServiceRequest request)
                throws ServiceException {
            throw new NotImplementedException();
        }

        @Override
        public MultiResponse multi(RpcController controller, MultiRequest request) throws ServiceException {
            int concurrentInvocations = this.multiInvocationsCount.incrementAndGet();
            try {
                if (concurrentInvocations >= tooManyMultiRequests) {
                    throw new ServiceException(
                            new RegionTooBusyException("concurrentInvocations=" + concurrentInvocations));
                }
                Threads.sleep(multiPause);
                return doMultiResponse(meta, sequenceids, request);
            } finally {
                this.multiInvocationsCount.decrementAndGet();
            }
        }
    }

    static ScanResponse doMetaScanResponse(final SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta,
            final AtomicLong sequenceids, final ScanRequest request) {
        ScanResponse.Builder builder = ScanResponse.newBuilder();
        int max = request.getNumberOfRows();
        int count = 0;
        Map<byte[], Pair<HRegionInfo, ServerName>> tail = request.hasScan()
                ? meta.tailMap(request.getScan().getStartRow().toByteArray())
                : meta;
        ClientProtos.Result.Builder resultBuilder = ClientProtos.Result.newBuilder();
        for (Map.Entry<byte[], Pair<HRegionInfo, ServerName>> e : tail.entrySet()) {
            // Can be 0 on open of a scanner -- i.e. rpc to setup scannerid only.
            if (max <= 0)
                break;
            if (++count > max)
                break;
            HRegionInfo hri = e.getValue().getFirst();
            ByteString row = HBaseZeroCopyByteString.wrap(hri.getRegionName());
            resultBuilder.clear();
            resultBuilder.addCell(getRegionInfo(row, hri));
            resultBuilder.addCell(getServer(row, e.getValue().getSecond()));
            resultBuilder.addCell(getStartCode(row));
            builder.addResults(resultBuilder.build());
            // Set more to false if we are on the last region in table.
            if (hri.getEndKey().length <= 0)
                builder.setMoreResults(false);
            else
                builder.setMoreResults(true);
        }
        // If no scannerid, set one.
        builder.setScannerId(request.hasScannerId() ? request.getScannerId() : sequenceids.incrementAndGet());
        return builder.build();
    }

    static GetResponse doMetaGetResponse(final SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta,
            final GetRequest request) {
        ClientProtos.Result.Builder resultBuilder = ClientProtos.Result.newBuilder();
        ByteString row = request.getGet().getRow();
        Pair<HRegionInfo, ServerName> p = meta.get(row.toByteArray());
        if (p == null) {
            if (request.getGet().getClosestRowBefore()) {
                byte[] bytes = row.toByteArray();
                SortedMap<byte[], Pair<HRegionInfo, ServerName>> head = bytes != null ? meta.headMap(bytes) : meta;
                p = head == null ? null : head.get(head.lastKey());
            }
        }
        if (p != null) {
            resultBuilder.addCell(getRegionInfo(row, p.getFirst()));
            resultBuilder.addCell(getServer(row, p.getSecond()));
        }
        resultBuilder.addCell(getStartCode(row));
        GetResponse.Builder builder = GetResponse.newBuilder();
        builder.setResult(resultBuilder.build());
        return builder.build();
    }

    /**
     * @param name region name or encoded region name.
     * @param type
     * @return True if we are dealing with a hbase:meta region.
     */
    static boolean isMetaRegion(final byte[] name, final RegionSpecifierType type) {
        switch (type) {
        case REGION_NAME:
            return Bytes.equals(HRegionInfo.FIRST_META_REGIONINFO.getRegionName(), name);
        case ENCODED_REGION_NAME:
            return Bytes.equals(HRegionInfo.FIRST_META_REGIONINFO.getEncodedNameAsBytes(), name);
        default:
            throw new UnsupportedOperationException();
        }
    }

    private final static ByteString CATALOG_FAMILY_BYTESTRING = HBaseZeroCopyByteString
            .wrap(HConstants.CATALOG_FAMILY);
    private final static ByteString REGIONINFO_QUALIFIER_BYTESTRING = HBaseZeroCopyByteString
            .wrap(HConstants.REGIONINFO_QUALIFIER);
    private final static ByteString SERVER_QUALIFIER_BYTESTRING = HBaseZeroCopyByteString
            .wrap(HConstants.SERVER_QUALIFIER);

    static CellProtos.Cell.Builder getBaseCellBuilder(final ByteString row) {
        CellProtos.Cell.Builder cellBuilder = CellProtos.Cell.newBuilder();
        cellBuilder.setRow(row);
        cellBuilder.setFamily(CATALOG_FAMILY_BYTESTRING);
        cellBuilder.setTimestamp(System.currentTimeMillis());
        return cellBuilder;
    }

    static CellProtos.Cell getRegionInfo(final ByteString row, final HRegionInfo hri) {
        CellProtos.Cell.Builder cellBuilder = getBaseCellBuilder(row);
        cellBuilder.setQualifier(REGIONINFO_QUALIFIER_BYTESTRING);
        cellBuilder.setValue(HBaseZeroCopyByteString.wrap(hri.toByteArray()));
        return cellBuilder.build();
    }

    static CellProtos.Cell getServer(final ByteString row, final ServerName sn) {
        CellProtos.Cell.Builder cellBuilder = getBaseCellBuilder(row);
        cellBuilder.setQualifier(SERVER_QUALIFIER_BYTESTRING);
        cellBuilder.setValue(ByteString.copyFromUtf8(sn.getHostAndPort()));
        return cellBuilder.build();
    }

    static CellProtos.Cell getStartCode(final ByteString row) {
        CellProtos.Cell.Builder cellBuilder = getBaseCellBuilder(row);
        cellBuilder.setQualifier(HBaseZeroCopyByteString.wrap(HConstants.STARTCODE_QUALIFIER));
        // TODO:
        cellBuilder.setValue(HBaseZeroCopyByteString.wrap(Bytes.toBytes(META_SERVERNAME.getStartcode())));
        return cellBuilder.build();
    }

    private static final byte[] BIG_USER_TABLE = Bytes.toBytes("t");

    /**
     * Format passed integer.  Zero-pad.
     * Copied from hbase-server PE class and small amendment.  Make them share.
     * @param number
     * @return Returns zero-prefixed 10-byte wide decimal version of passed
     * number (Does absolute in case number is negative).
     */
    private static byte[] format(final long number) {
        byte[] b = new byte[10];
        long d = number;
        for (int i = b.length - 1; i >= 0; i--) {
            b[i] = (byte) ((d % 10) + '0');
            d /= 10;
        }
        return b;
    }

    /**
     * @param count
     * @param namespaceSpan
     * @return <code>count</code> regions
     */
    private static HRegionInfo[] makeHRegionInfos(final byte[] tableName, final int count,
            final long namespaceSpan) {
        byte[] startKey = HConstants.EMPTY_BYTE_ARRAY;
        byte[] endKey = HConstants.EMPTY_BYTE_ARRAY;
        long interval = namespaceSpan / count;
        HRegionInfo[] hris = new HRegionInfo[count];
        for (int i = 0; i < count; i++) {
            if (i == 0) {
                endKey = format(interval);
            } else {
                startKey = endKey;
                if (i == count - 1)
                    endKey = HConstants.EMPTY_BYTE_ARRAY;
                else
                    endKey = format((i + 1) * interval);
            }
            hris[i] = new HRegionInfo(TableName.valueOf(tableName), startKey, endKey);
        }
        return hris;
    }

    /**
     * @param count
     * @return Return <code>count</code> servernames.
     */
    private static ServerName[] makeServerNames(final int count) {
        ServerName[] sns = new ServerName[count];
        for (int i = 0; i < count; i++) {
            sns[i] = ServerName.valueOf("" + i + ".example.org", 16010, i);
        }
        return sns;
    }

    /**
     * Comparator for meta row keys.
     */
    private static class MetaRowsComparator implements Comparator<byte[]> {
        private final KeyValue.KVComparator delegate = new KeyValue.MetaComparator();

        @Override
        public int compare(byte[] left, byte[] right) {
            return delegate.compareRows(left, 0, left.length, right, 0, right.length);
        }
    }

    /**
     * Create up a map that is keyed by meta row name and whose value is the HRegionInfo and
     * ServerName to return for this row.
     * @return Map with faked hbase:meta content in it.
     */
    static SortedMap<byte[], Pair<HRegionInfo, ServerName>> makeMeta(final byte[] tableName, final int regionCount,
            final long namespaceSpan, final int serverCount) {
        // I need a comparator for meta rows so we sort properly.
        SortedMap<byte[], Pair<HRegionInfo, ServerName>> meta = new ConcurrentSkipListMap<byte[], Pair<HRegionInfo, ServerName>>(
                new MetaRowsComparator());
        HRegionInfo[] hris = makeHRegionInfos(tableName, regionCount, namespaceSpan);
        ServerName[] serverNames = makeServerNames(serverCount);
        int per = regionCount / serverCount;
        int count = 0;
        for (HRegionInfo hri : hris) {
            Pair<HRegionInfo, ServerName> p = new Pair<HRegionInfo, ServerName>(hri, serverNames[count++ / per]);
            meta.put(hri.getRegionName(), p);
        }
        return meta;
    }

    /**
     * Code for each 'client' to run.
     *
     * @param id
     * @param c
     * @param sharedConnection
     * @throws IOException
     */
    static void cycle(int id, final Configuration c, final HConnection sharedConnection) throws IOException {
        HTableInterface table = sharedConnection.getTable(BIG_USER_TABLE);
        table.setAutoFlushTo(false);
        long namespaceSpan = c.getLong("hbase.test.namespace.span", 1000000);
        long startTime = System.currentTimeMillis();
        final int printInterval = 100000;
        Random rd = new Random(id);
        boolean get = c.getBoolean("hbase.test.do.gets", false);
        try {
            Stopwatch stopWatch = new Stopwatch();
            stopWatch.start();
            for (int i = 0; i < namespaceSpan; i++) {
                byte[] b = format(rd.nextLong());
                if (get) {
                    Get g = new Get(b);
                    table.get(g);
                } else {
                    Put p = new Put(b);
                    p.add(HConstants.CATALOG_FAMILY, b, b);
                    table.put(p);
                }
                if (i % printInterval == 0) {
                    LOG.info("Put " + printInterval + "/" + stopWatch.elapsedMillis());
                    stopWatch.reset();
                    stopWatch.start();
                }
            }
            LOG.info("Finished a cycle putting " + namespaceSpan + " in " + (System.currentTimeMillis() - startTime)
                    + "ms");
        } finally {
            table.close();
        }
    }

    @Override
    public int run(String[] arg0) throws Exception {
        int errCode = 0;
        // TODO: Make command options.
        // How many servers to fake.
        final int servers = 1;
        // How many regions to put on the faked servers.
        final int regions = 100000;
        // How many 'keys' in the faked regions.
        final long namespaceSpan = 50000000;
        // How long to take to pause after doing a put; make this long if you want to fake a struggling
        // server.
        final long multiPause = 0;
        // Check args make basic sense.
        if ((namespaceSpan < regions) || (regions < servers)) {
            throw new IllegalArgumentException("namespaceSpan=" + namespaceSpan + " must be > regions=" + regions
                    + " which must be > servers=" + servers);
        }

        // Set my many servers and many regions faking connection in place.
        getConf().set("hbase.client.connection.impl", ManyServersManyRegionsConnection.class.getName());
        // Use simple kv registry rather than zk
        getConf().set("hbase.client.registry.impl", SimpleRegistry.class.getName());
        // When to report fails.  Default is we report the 10th.  This means we'll see log everytime
        // an exception is thrown -- usually RegionTooBusyException when we have more than
        // hbase.test.multi.too.many requests outstanding at any time.
        getConf().setInt("hbase.client.start.log.errors.counter", 0);

        // Ugly but this is only way to pass in configs.into ManyServersManyRegionsConnection class.
        getConf().setInt("hbase.test.regions", regions);
        getConf().setLong("hbase.test.namespace.span", namespaceSpan);
        getConf().setLong("hbase.test.servers", servers);
        getConf().set("hbase.test.tablename", Bytes.toString(BIG_USER_TABLE));
        getConf().setLong("hbase.test.multi.pause.when.done", multiPause);
        // Let there be ten outstanding requests at a time before we throw RegionBusyException.
        getConf().setInt("hbase.test.multi.too.many", 10);
        final int clients = 2;

        // Have them all share the same connection so they all share the same instance of
        // ManyServersManyRegionsConnection so I can keep an eye on how many requests by server.
        final ExecutorService pool = Executors.newCachedThreadPool(Threads.getNamedThreadFactory("p"));
        // Executors.newFixedThreadPool(servers * 10, Threads.getNamedThreadFactory("p"));
        // Share a connection so I can keep counts in the 'server' on concurrency.
        final HConnection sharedConnection = HConnectionManager.createConnection(getConf()/*, pool*/);
        try {
            Thread[] ts = new Thread[clients];
            for (int j = 0; j < ts.length; j++) {
                final int id = j;
                ts[j] = new Thread("" + j) {
                    final Configuration c = getConf();

                    @Override
                    public void run() {
                        try {
                            cycle(id, c, sharedConnection);
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }
                };
                ts[j].start();
            }
            for (int j = 0; j < ts.length; j++) {
                ts[j].join();
            }
        } finally {
            sharedConnection.close();
        }
        return errCode;
    }

    /**
     * Run a client instance against a faked up server.
     * @param args TODO
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        System.exit(ToolRunner.run(HBaseConfiguration.create(), new TestClientNoCluster(), args));
    }
}