Merge pull request #777 from metamx/initialized-endpoint

Historical endpoints accessible while loading + new loadstatus endpoint

histogram/src/main/java/io/druid/query/aggregation/histogram/ApproximateHistogram.java

@@ -1019,8 +1019,6 @@ public class ApproximateHistogram
    * @param count        current size of the heap
    * @param heapIndex    index of the item to be deleted
    * @param values       values stored in the heap
-   *
-   * @return
    */
   private static int heapDelete(int[] heap, int[] reverseIndex, int count, int heapIndex, float[] values)
   {

processing/src/main/java/io/druid/query/aggregation/hyperloglog/HyperLogLogCollector.java

@@ -200,9 +200,6 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
   /**
    * Checks if the payload for the given ByteBuffer is sparse or not.
    * The given buffer must be positioned at getPayloadBytePosition() prior to calling isSparse
-   *
-   * @param buffer
-   * @return
    */
   private static boolean isSparse(ByteBuffer buffer)
   {
@@ -636,8 +633,6 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
    * @param position   The position into the byte buffer, this position represents two "registers"
    * @param offsetDiff The difference in offset between the byteToAdd and the current HyperLogLogCollector
    * @param byteToAdd  The byte to merge into the current HyperLogLogCollector
-   *
-   * @return
    */
   private static int mergeAndStoreByteRegister(
       final ByteBuffer storageBuffer,

processing/src/main/java/io/druid/query/groupby/having/HavingSpec.java

@@ -49,8 +49,6 @@ public interface HavingSpec
    * @param row A Row of data that may contain aggregated values
    *
    * @return true if the given row satisfies the having spec. False otherwise.
-   *
-   * @see Row
    */
   public boolean eval(Row row);
 

processing/src/main/java/io/druid/segment/data/CompressedFloatsIndexedSupplier.java

@@ -173,8 +173,6 @@ public class CompressedFloatsIndexedSupplier implements Supplier<IndexedFloats>
 
   /**
    * For testing. Do not depend on unless you like things breaking.
-   * 
-   * @return
    */
   GenericIndexed<ResourceHolder<FloatBuffer>> getBaseFloatBuffers()
   {

processing/src/main/java/io/druid/segment/data/CompressedLongsIndexedSupplier.java

@@ -184,7 +184,6 @@ public class CompressedLongsIndexedSupplier implements Supplier<IndexedLongs>
 
   /**
    * For testing.  Do not use unless you like things breaking
-   * @return
    */
   GenericIndexed<ResourceHolder<LongBuffer>> getBaseLongBuffers()
   {

processing/src/main/java/io/druid/segment/incremental/IncrementalIndex.java

@@ -673,10 +673,9 @@ public class IncrementalIndex implements Iterable<Row>
       falseIdsReverse = biMap.inverse();
     }
 
-    /**
-     * Returns the interned String value to allow fast comparisons using `==` instead of `.equals()`
-     * @see io.druid.segment.incremental.IncrementalIndexStorageAdapter.EntryHolderValueMatcherFactory#makeValueMatcher(String, String)
-     */
+
+    // Returns the interned String value to allow fast comparisons using `==` instead of `.equals()`
+    // see io.druid.segment.incremental.IncrementalIndexStorageAdapter.EntryHolderValueMatcherFactory#makeValueMatcher(String, String)
     public String get(String value)
     {
       return value == null ? null : poorMansInterning.get(value);

processing/src/main/java/io/druid/segment/incremental/IncrementalIndexStorageAdapter.java

@@ -532,10 +532,8 @@ public class IncrementalIndexStorageAdapter implements StorageAdapter
           }
 
           for (String dimVal : dims[dimIndex]) {
-            /**
-             * using == here instead of .equals() to speed up lookups made possible by
-             * {@link io.druid.segment.incremental.IncrementalIndex.DimDim#poorMansInterning}
-             */
+            // using == here instead of .equals() to speed up lookups made possible by
+            // io.druid.segment.incremental.IncrementalIndex.DimDim#poorMansInterning
             if (id == dimVal) {
               return true;
             }

server/src/main/java/io/druid/server/coordination/BaseZkCoordinator.java

@@ -37,7 +37,6 @@ import org.apache.curator.framework.recipes.cache.PathChildrenCacheListener;
 import org.apache.curator.utils.ZKPaths;
 
 import java.io.IOException;
-import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
 /**
@@ -212,6 +211,11 @@ public abstract class BaseZkCoordinator implements DataSegmentChangeHandler
     }
   }
 
+  public boolean isStarted()
+  {
+    return started;
+  }
+
   public abstract void loadLocalCache();
 
   public abstract DataSegmentChangeHandler getDataSegmentChangeHandler();

server/src/main/java/io/druid/server/coordination/ZkCoordinator.java

@@ -169,7 +169,7 @@ public class ZkCoordinator extends BaseZkCoordinator
         catch (IOException e) {
           throw new SegmentLoadingException(e, "Failed to announce segment[%s]", segment.getIdentifier());
         }
-      };
+      }
     }
     catch (SegmentLoadingException e) {
       log.makeAlert(e, "Failed to load segment for dataSource")

server/src/main/java/io/druid/server/http/HistoricalResource.java

@@ -0,0 +1,32 @@
+package io.druid.server.http;
+
+import com.google.common.collect.ImmutableMap;
+import io.druid.server.coordination.ZkCoordinator;
+
+import javax.inject.Inject;
+import javax.ws.rs.GET;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Response;
+
+@Path("/druid/historical/v1")
+public class HistoricalResource
+{
+  private final ZkCoordinator coordinator;
+
+  @Inject
+  public HistoricalResource(
+      ZkCoordinator coordinator
+  )
+  {
+    this.coordinator = coordinator;
+  }
+
+  @GET
+  @Path("/loadstatus")
+  @Produces("application/json")
+  public Response getLoadStatus()
+  {
+    return Response.ok(ImmutableMap.of("cacheInitialized", coordinator.isStarted())).build();
+  }
+}

services/src/main/java/io/druid/cli/CliHistorical.java

@@ -38,6 +38,7 @@ import io.druid.query.QuerySegmentWalker;
 import io.druid.server.QueryResource;
 import io.druid.server.coordination.ServerManager;
 import io.druid.server.coordination.ZkCoordinator;
+import io.druid.server.http.HistoricalResource;
 import io.druid.server.initialization.JettyServerInitializer;
 import io.druid.server.metrics.MetricsModule;
 import org.eclipse.jetty.server.Server;
@@ -68,6 +69,8 @@ public class CliHistorical extends ServerRunnable
           @Override
           public void configure(Binder binder)
           {
+            // register Server before binding ZkCoordinator to ensure HTTP endpoints are available immediately
+            LifecycleModule.register(binder, Server.class);
             binder.bind(ServerManager.class).in(LazySingleton.class);
             binder.bind(ZkCoordinator.class).in(ManageLifecycle.class);
             binder.bind(QuerySegmentWalker.class).to(ServerManager.class).in(LazySingleton.class);
@@ -75,10 +78,10 @@ public class CliHistorical extends ServerRunnable
             binder.bind(NodeTypeConfig.class).toInstance(new NodeTypeConfig("historical"));
             binder.bind(JettyServerInitializer.class).to(QueryJettyServerInitializer.class).in(LazySingleton.class);
             Jerseys.addResource(binder, QueryResource.class);
+            Jerseys.addResource(binder, HistoricalResource.class);
             LifecycleModule.register(binder, QueryResource.class);
-
+            LifecycleModule.register(binder, HistoricalResource.class);
             LifecycleModule.register(binder, ZkCoordinator.class);
-            LifecycleModule.register(binder, Server.class);
 
             binder.bind(Cache.class).toProvider(CacheProvider.class).in(ManageLifecycle.class);
             JsonConfigProvider.bind(binder, "druid.historical.cache", CacheProvider.class);