Merge pull request #142 from metamx/improve-bard

Enable the broker to select a compute node will the least number of open connections

client/src/main/java/com/metamx/druid/client/BrokerServerView.java

@@ -24,6 +24,7 @@ import com.google.common.collect.Maps;
 import com.google.common.collect.Ordering;
 import com.metamx.common.logger.Logger;
 import com.metamx.druid.VersionedIntervalTimeline;
+import com.metamx.druid.client.selector.QueryableDruidServer;
 import com.metamx.druid.client.selector.ServerSelector;
 import com.metamx.druid.partition.PartitionChunk;
 import com.metamx.druid.query.QueryRunner;
@@ -44,7 +45,7 @@ public class BrokerServerView implements TimelineServerView
 
   private final Object lock = new Object();
 
-  private final ConcurrentMap<DruidServer, DirectDruidClient> clients;
+  private final ConcurrentMap<String, QueryableDruidServer> clients;
   private final Map<String, ServerSelector> selectors;
   private final Map<String, VersionedIntervalTimeline<String, ServerSelector>> timelines;
 
@@ -107,7 +108,7 @@ public class BrokerServerView implements TimelineServerView
   public void clear()
   {
     synchronized (lock) {
-      final Iterator<DruidServer> clientsIter = clients.keySet().iterator();
+      final Iterator<String> clientsIter = clients.keySet().iterator();
       while (clientsIter.hasNext()) {
         clientsIter.remove();
       }
@@ -119,7 +120,7 @@ public class BrokerServerView implements TimelineServerView
         final ServerSelector selector = selectorsIter.next();
         selectorsIter.remove();
         while (!selector.isEmpty()) {
-          final DruidServer pick = selector.pick();
+          final QueryableDruidServer pick = selector.pick();
           selector.removeServer(pick);
         }
       }
@@ -128,7 +129,10 @@ public class BrokerServerView implements TimelineServerView
 
   private void addServer(DruidServer server)
   {
-    QueryRunner exists = clients.put(server, makeDirectClient(server));
+    QueryableDruidServer exists = clients.put(
+        server.getName(),
+        new QueryableDruidServer(server, makeDirectClient(server))
+    );
     if (exists != null) {
       log.warn("QueryRunner for server[%s] already existed!?", server);
     }
@@ -141,7 +145,7 @@ public class BrokerServerView implements TimelineServerView
 
   private void removeServer(DruidServer server)
   {
-    clients.remove(server);
+    clients.remove(server.getName());
     for (DataSegment segment : server.getSegments().values()) {
       serverRemovedSegment(server, segment);
     }
@@ -167,10 +171,10 @@ public class BrokerServerView implements TimelineServerView
         selectors.put(segmentId, selector);
       }
 
-      if (!clients.containsKey(server)) {
+      if (!clients.containsKey(server.getName())) {
         addServer(server);
       }
-      selector.addServer(server);
+      selector.addServer(clients.get(server.getName()));
     }
   }
 
@@ -188,7 +192,8 @@ public class BrokerServerView implements TimelineServerView
         return;
       }
 
-      if (!selector.removeServer(server)) {
+      QueryableDruidServer queryableDruidServer = clients.get(server.getName());
+      if (!selector.removeServer(queryableDruidServer)) {
         log.warn(
             "Asked to disassociate non-existant association between server[%s] and segment[%s]",
             server,
@@ -228,7 +233,11 @@ public class BrokerServerView implements TimelineServerView
   public <T> QueryRunner<T> getQueryRunner(DruidServer server)
   {
     synchronized (lock) {
-      return clients.get(server);
+      QueryableDruidServer queryableDruidServer = clients.get(server.getName());
+      if (queryableDruidServer == null) {
+        log.error("WTF?! No QueryableDruidServer found for %s", server.getName());
+      }
+      return queryableDruidServer.getClient();
     }
   }
 

client/src/main/java/com/metamx/druid/client/CachingClusteredClient.java

@@ -203,7 +203,7 @@ public class CachingClusteredClient<T> implements QueryRunner<T>
 
     // Compile list of all segments not pulled from cache
     for(Pair<ServerSelector, SegmentDescriptor> segment : segments) {
-      final DruidServer server = segment.lhs.pick();
+      final DruidServer server = segment.lhs.pick().getServer();
       List<SegmentDescriptor> descriptors = serverSegments.get(server);
 
       if (descriptors == null) {

client/src/main/java/com/metamx/druid/client/DirectDruidClient.java

@@ -47,7 +47,6 @@ import com.metamx.http.client.HttpClient;
 import com.metamx.http.client.io.AppendableByteArrayInputStream;
 import com.metamx.http.client.response.ClientResponse;
 import com.metamx.http.client.response.InputStreamResponseHandler;
-
 import org.jboss.netty.handler.codec.http.HttpChunk;
 import org.jboss.netty.handler.codec.http.HttpHeaders;
 import org.jboss.netty.handler.codec.http.HttpResponse;
@@ -60,6 +59,7 @@ import java.util.Iterator;
 import java.util.Map;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
+import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  */
@@ -74,6 +74,7 @@ public class DirectDruidClient<T> implements QueryRunner<T>
   private final HttpClient httpClient;
   private final String host;
 
+  private final AtomicInteger openConnections;
   private final boolean isSmile;
 
   public DirectDruidClient(
@@ -88,7 +89,13 @@ public class DirectDruidClient<T> implements QueryRunner<T>
     this.httpClient = httpClient;
     this.host = host;
 
-    isSmile = this.objectMapper.getJsonFactory() instanceof SmileFactory;
+    this.isSmile = this.objectMapper.getJsonFactory() instanceof SmileFactory;
+    this.openConnections = new AtomicInteger();
+  }
+
+  public int getNumOpenConnections()
+  {
+    return openConnections.get();
   }
 
   @Override
@@ -121,6 +128,7 @@ public class DirectDruidClient<T> implements QueryRunner<T>
 
     try {
       log.debug("Querying url[%s]", url);
+      openConnections.getAndIncrement();
       future = httpClient
           .post(new URL(url))
           .setContent(objectMapper.writeValueAsBytes(query))
@@ -128,7 +136,6 @@ public class DirectDruidClient<T> implements QueryRunner<T>
           .go(
               new InputStreamResponseHandler()
               {
-
                 long startTime;
                 long byteCount = 0;
 
@@ -162,6 +169,7 @@ public class DirectDruidClient<T> implements QueryRunner<T>
                       stopTime - startTime,
                       byteCount / (0.0001 * (stopTime - startTime))
                   );
+                  openConnections.getAndDecrement();
                   return super.done(clientResponse);
                 }
               }

client/src/main/java/com/metamx/druid/client/selector/QueryableDruidServer.java

@@ -0,0 +1,47 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package com.metamx.druid.client.selector;
+
+import com.metamx.druid.client.DirectDruidClient;
+import com.metamx.druid.client.DruidServer;
+
+/**
+ */
+public class QueryableDruidServer
+{
+  private final DruidServer server;
+  private final DirectDruidClient client;
+
+  public QueryableDruidServer(DruidServer server, DirectDruidClient client)
+  {
+    this.server = server;
+    this.client = client;
+  }
+
+  public DruidServer getServer()
+  {
+    return server;
+  }
+
+  public DirectDruidClient getClient()
+  {
+    return client;
+  }
+}

client/src/main/java/com/metamx/druid/client/selector/ServerSelector.java

@@ -19,21 +19,30 @@
 
 package com.metamx.druid.client.selector;
 
-import com.google.common.collect.Iterables;
 import com.google.common.collect.Sets;
+import com.google.common.primitives.Ints;
 import com.metamx.druid.client.DataSegment;
 import com.metamx.druid.client.DruidServer;
 
-import java.util.LinkedHashSet;
+import java.util.Collections;
-import java.util.Random;
+import java.util.Comparator;
+import java.util.Set;
 
 /**
  */
 public class ServerSelector
 {
-  private static final Random random = new Random();
+  private static final Comparator<QueryableDruidServer> comparator = new Comparator<QueryableDruidServer>()
+  {
+    @Override
+    public int compare(QueryableDruidServer left, QueryableDruidServer right)
+    {
+      return Ints.compare(left.getClient().getNumOpenConnections(), right.getClient().getNumOpenConnections());
+    }
+  };
+
+  private final Set<QueryableDruidServer> servers = Sets.newHashSet();
 
-  private final LinkedHashSet<DruidServer> servers = Sets.newLinkedHashSet();
   private final DataSegment segment;
 
   public ServerSelector(
@@ -49,7 +58,7 @@ public class ServerSelector
   }
 
   public void addServer(
-      DruidServer server
+      QueryableDruidServer server
   )
   {
     synchronized (this) {
@@ -57,7 +66,7 @@ public class ServerSelector
     }
   }
 
-  public boolean removeServer(DruidServer server)
+  public boolean removeServer(QueryableDruidServer server)
   {
     synchronized (this) {
       return servers.remove(server);
@@ -71,15 +80,10 @@ public class ServerSelector
     }
   }
 
-  public DruidServer pick()
+  public QueryableDruidServer pick()
   {
     synchronized (this) {
-      final int size = servers.size();
+      return Collections.min(servers, comparator);
-      switch (size) {
-        case 0: return null;
-        case 1: return servers.iterator().next();
-        default: return Iterables.get(servers, random.nextInt(size));
-      }
     }
   }
 }

client/src/test/java/com/metamx/druid/client/selector/ServerSelectorTest.java

@@ -0,0 +1,121 @@
+/*
+ * Druid - a distributed column store.
+ * Copyright (C) 2012  Metamarkets Group Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+
+package com.metamx.druid.client.selector;
+
+import com.fasterxml.jackson.dataformat.smile.SmileFactory;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.util.concurrent.SettableFuture;
+import com.metamx.druid.Druids;
+import com.metamx.druid.client.DataSegment;
+import com.metamx.druid.client.DirectDruidClient;
+import com.metamx.druid.jackson.DefaultObjectMapper;
+import com.metamx.druid.query.ReflectionQueryToolChestWarehouse;
+import com.metamx.druid.query.timeboundary.TimeBoundaryQuery;
+import com.metamx.druid.shard.NoneShardSpec;
+import com.metamx.http.client.HttpClient;
+import com.metamx.http.client.Request;
+import com.metamx.http.client.RequestBuilder;
+import junit.framework.Assert;
+import org.easymock.EasyMock;
+import org.jboss.netty.handler.codec.http.HttpMethod;
+import org.joda.time.DateTime;
+import org.joda.time.Interval;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.net.URL;
+
+/**
+ */
+public class ServerSelectorTest
+{
+  private HttpClient httpClient;
+
+  @Before
+  public void setUp() throws Exception
+  {
+    httpClient = EasyMock.createMock(HttpClient.class);
+  }
+
+  @Test
+  public void testPick() throws Exception
+  {
+    RequestBuilder requestBuilder = new RequestBuilder(httpClient, HttpMethod.POST, new URL("http://foo.com"));
+    EasyMock.expect(httpClient.post(EasyMock.<URL>anyObject())).andReturn(requestBuilder).atLeastOnce();
+    EasyMock.expect(httpClient.go(EasyMock.<Request>anyObject())).andReturn(SettableFuture.create()).atLeastOnce();
+    EasyMock.replay(httpClient);
+
+    final ServerSelector serverSelector = new ServerSelector(
+        new DataSegment(
+            "test",
+            new Interval("2013-01-01/2013-01-02"),
+            new DateTime("2013-01-01").toString(),
+            Maps.<String, Object>newHashMap(),
+            Lists.<String>newArrayList(),
+            Lists.<String>newArrayList(),
+            new NoneShardSpec(),
+            0,
+            0L
+        )
+    );
+
+    DirectDruidClient client1 = new DirectDruidClient(
+        new ReflectionQueryToolChestWarehouse(),
+        new DefaultObjectMapper(new SmileFactory()),
+        httpClient,
+        "foo"
+    );
+    DirectDruidClient client2 = new DirectDruidClient(
+        new ReflectionQueryToolChestWarehouse(),
+        new DefaultObjectMapper(new SmileFactory()),
+        httpClient,
+        "foo2"
+    );
+
+    QueryableDruidServer queryableDruidServer1 = new QueryableDruidServer(
+        null,
+        client1
+    );
+    serverSelector.addServer(queryableDruidServer1);
+    QueryableDruidServer queryableDruidServer2 = new QueryableDruidServer(
+        null,
+        client2
+    );
+    serverSelector.addServer(queryableDruidServer2);
+
+    TimeBoundaryQuery query = Druids.newTimeBoundaryQueryBuilder().dataSource("test").build();
+
+    client1.run(query);
+    client1.run(query);
+    client1.run(query);
+
+    Assert.assertTrue(client1.getNumOpenConnections() == 3);
+
+    client2.run(query);
+    client2.run(query);
+
+    Assert.assertTrue(client2.getNumOpenConnections() == 2);
+
+    Assert.assertTrue(serverSelector.pick() == queryableDruidServer2);
+
+    EasyMock.verify(httpClient);
+  }
+}

index-common/src/main/java/com/metamx/druid/index/column/ColumnDescriptor.java

@@ -74,9 +74,9 @@ public class ColumnDescriptor
     return parts;
   }
 
-  public int numBytes()
+  public long numBytes()
   {
-    int retVal = 0;
+    long retVal = 0;
 
     for (ColumnPartSerde part : parts) {
       retVal += part.numBytes();

index-common/src/main/java/com/metamx/druid/index/serde/ColumnPartSerde.java

@@ -38,7 +38,7 @@ import java.nio.channels.WritableByteChannel;
 })
 public interface ColumnPartSerde
 {
-  public int numBytes();
+  public long numBytes();
   public void write(WritableByteChannel channel) throws IOException;
   public ColumnPartSerde read(ByteBuffer buffer, ColumnBuilder builder);
 }

index-common/src/main/java/com/metamx/druid/index/serde/ComplexColumnPartSerde.java

@@ -61,7 +61,7 @@ public class ComplexColumnPartSerde implements ColumnPartSerde
   }
 
   @Override
-  public int numBytes()
+  public long numBytes()
   {
     return column.getSerializedSize();
   }

index-common/src/main/java/com/metamx/druid/index/serde/DictionaryEncodedColumnPartSerde.java

@@ -49,7 +49,7 @@ public class DictionaryEncodedColumnPartSerde implements ColumnPartSerde
   private final VSizeIndexed multiValuedColumn;
   private final GenericIndexed<ImmutableConciseSet> bitmaps;
 
-  private final int size;
+  private final long size;
 
   public DictionaryEncodedColumnPartSerde(
       GenericIndexed<String> dictionary,
@@ -63,7 +63,7 @@ public class DictionaryEncodedColumnPartSerde implements ColumnPartSerde
     this.multiValuedColumn = multiValCol;
     this.bitmaps = bitmaps;
 
-    int size = dictionary.getSerializedSize();
+    long size = dictionary.getSerializedSize();
     if (singleValCol != null && multiValCol == null) {
       size += singleValCol.getSerializedSize();
     }
@@ -94,7 +94,7 @@ public class DictionaryEncodedColumnPartSerde implements ColumnPartSerde
   }
 
   @Override
-  public int numBytes()
+  public long numBytes()
   {
     return 1 + size;
   }

index-common/src/main/java/com/metamx/druid/index/serde/FloatGenericColumnPartSerde.java

@@ -58,7 +58,7 @@ public class FloatGenericColumnPartSerde implements ColumnPartSerde
   }
 
   @Override
-  public int numBytes()
+  public long numBytes()
   {
     return compressedFloats.getSerializedSize();
   }

index-common/src/main/java/com/metamx/druid/index/serde/LongGenericColumnPartSerde.java

@@ -58,7 +58,7 @@ public class LongGenericColumnPartSerde implements ColumnPartSerde
   }
 
   @Override
-  public int numBytes()
+  public long numBytes()
   {
     return compressedLongs.getSerializedSize();
   }

index-common/src/main/java/com/metamx/druid/index/v1/CompressedFloatsIndexedSupplier.java

@@ -150,7 +150,7 @@ public class CompressedFloatsIndexedSupplier implements Supplier<IndexedFloats>
     };
   }
 
-  public int getSerializedSize()
+  public long getSerializedSize()
   {
     return baseFloatBuffers.getSerializedSize() + 1 + 4 + 4;
   }

index-common/src/main/java/com/metamx/druid/index/v1/CompressedLongsIndexedSupplier.java

@@ -161,7 +161,7 @@ public class CompressedLongsIndexedSupplier implements Supplier<IndexedLongs>
     };
   }
 
-  public int getSerializedSize()
+  public long getSerializedSize()
   {
     return baseLongBuffers.getSerializedSize() + 1 + 4 + 4;
   }

index-common/src/main/java/com/metamx/druid/index/v1/IndexIO.java

@@ -630,7 +630,7 @@ public class IndexIO
 
       GenericIndexed<String> cols = GenericIndexed.fromIterable(columns, GenericIndexed.stringStrategy);
 
-      final int numBytes = cols.getSerializedSize() + dims9.getSerializedSize() + 16;
+      final long numBytes = cols.getSerializedSize() + dims9.getSerializedSize() + 16;
       final SmooshedWriter writer = v9Smoosher.addWithSmooshedWriter("index.drd", numBytes);
       cols.writeToChannel(writer);
       dims9.writeToChannel(writer);

index-common/src/main/java/com/metamx/druid/kv/GenericIndexed.java

@@ -207,7 +207,7 @@ public class GenericIndexed<T> implements Indexed<T>
     return -(minIndex + 1);
   }
 
-  public int getSerializedSize()
+  public long getSerializedSize()
   {
     return theBuffer.remaining() + 2 + 4 + 4;
   }

merger/src/main/java/com/metamx/druid/merger/coordinator/ThreadPoolTaskRunner.java

@@ -28,7 +28,6 @@ import com.google.common.util.concurrent.Futures;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.ListeningExecutorService;
 import com.google.common.util.concurrent.MoreExecutors;
-import com.metamx.common.guava.FunctionalIterable;
 import com.metamx.common.lifecycle.LifecycleStop;
 import com.metamx.druid.Query;
 import com.metamx.druid.merger.common.TaskStatus;
@@ -51,20 +50,19 @@ import java.util.Set;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ConcurrentSkipListSet;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.ThreadPoolExecutor;
 
 /**
  * Runs tasks in a JVM thread using an ExecutorService.
  */
-public class ExecutorServiceTaskRunner implements TaskRunner, QuerySegmentWalker
+public class ThreadPoolTaskRunner implements TaskRunner, QuerySegmentWalker
 {
   private final TaskToolboxFactory toolboxFactory;
   private final ListeningExecutorService exec;
   private final Set<TaskRunnerWorkItem> runningItems = new ConcurrentSkipListSet<TaskRunnerWorkItem>();
 
-  private static final EmittingLogger log = new EmittingLogger(ExecutorServiceTaskRunner.class);
+  private static final EmittingLogger log = new EmittingLogger(ThreadPoolTaskRunner.class);
 
-  public ExecutorServiceTaskRunner(
+  public ThreadPoolTaskRunner(
       TaskToolboxFactory toolboxFactory,
       ExecutorService exec
   )

merger/src/main/java/com/metamx/druid/merger/worker/executor/ExecutorNode.java

@@ -59,7 +59,7 @@ import com.metamx.druid.merger.common.config.TaskConfig;
 import com.metamx.druid.merger.common.index.EventReceiverFirehoseFactory;
 import com.metamx.druid.merger.common.index.ChatHandlerProvider;
 import com.metamx.druid.merger.common.index.StaticS3FirehoseFactory;
-import com.metamx.druid.merger.coordinator.ExecutorServiceTaskRunner;
+import com.metamx.druid.merger.coordinator.ThreadPoolTaskRunner;
 import com.metamx.druid.merger.worker.config.ChatHandlerProviderConfig;
 import com.metamx.druid.merger.worker.config.WorkerConfig;
 import com.metamx.druid.utils.PropUtils;
@@ -118,7 +118,7 @@ public class ExecutorNode extends BaseServerNode<ExecutorNode>
   private ServiceAnnouncer serviceAnnouncer = null;
   private ServiceProvider coordinatorServiceProvider = null;
   private Server server = null;
-  private ExecutorServiceTaskRunner taskRunner = null;
+  private ThreadPoolTaskRunner taskRunner = null;
   private ExecutorLifecycle executorLifecycle = null;
   private ChatHandlerProvider chatHandlerProvider = null;
 
@@ -247,7 +247,7 @@ public class ExecutorNode extends BaseServerNode<ExecutorNode>
     executorLifecycle.join();
   }
 
-  public ExecutorServiceTaskRunner getTaskRunner()
+  public ThreadPoolTaskRunner getTaskRunner()
   {
     return taskRunner;
   }
@@ -414,7 +414,7 @@ public class ExecutorNode extends BaseServerNode<ExecutorNode>
   {
     if (taskRunner == null) {
       this.taskRunner = lifecycle.addManagedInstance(
-          new ExecutorServiceTaskRunner(
+          new ThreadPoolTaskRunner(
               taskToolboxFactory,
               Executors.newSingleThreadExecutor(
                   new ThreadFactoryBuilder()

merger/src/test/java/com/metamx/druid/merger/coordinator/RemoteTaskRunnerTest.java

@@ -291,7 +291,7 @@ public class RemoteTaskRunnerTest
         new PathChildrenCache(cf, String.format("%s/worker1", tasksPath), true),
         cf,
         workerCuratorCoordinator,
-        new ExecutorServiceTaskRunner(
+        new ThreadPoolTaskRunner(
             new TaskToolboxFactory(
                 new TaskConfig()
                 {

merger/src/test/java/com/metamx/druid/merger/coordinator/TaskLifecycleTest.java

@@ -162,7 +162,7 @@ public class TaskLifecycleTest
         new DefaultObjectMapper()
     );
 
-    tr = new ExecutorServiceTaskRunner(
+    tr = new ThreadPoolTaskRunner(
         tb,
         Executors.newSingleThreadExecutor()
     );

server/src/main/java/com/metamx/druid/coordination/ServerManager.java

@@ -20,6 +20,7 @@
 package com.metamx.druid.coordination;
 
 import com.google.common.base.Function;
+import com.google.common.base.Predicates;
 import com.google.common.collect.Ordering;
 import com.metamx.common.ISE;
 import com.metamx.common.guava.FunctionalIterable;
@@ -257,6 +258,9 @@ public class ServerManager implements QuerySegmentWalker
                     );
               }
             }
+        )
+        .filter(
+            Predicates.<QueryRunner<T>>notNull()
         );
 
     return new FinalizeResultsQueryRunner<T>(toolChest.mergeResults(factory.mergeRunners(exec, adapters)), toolChest);

server/src/main/java/com/metamx/druid/master/DruidMasterConfig.java

@@ -51,13 +51,13 @@ public abstract class DruidMasterConfig
   @Config("druid.master.merger.on")
   public boolean isMergeSegments()
   {
-    return true;
+    return false;
   }
 
   @Config("druid.master.conversion.on")
   public boolean isConvertSegments()
   {
-    return true;
+    return false;
   }
 
   @Config("druid.master.merger.service")