Document HTTP based segment management and Deprecate classes to remove in future (#4997)

* document http segment management

* deprecated classes that shouldn't be used any further

docs/content/configuration/broker.md

@@ -109,6 +109,11 @@ You can optionally only configure caching to be enabled on the broker by setting
 
 See [cache configuration](caching.html) for how to configure cache settings.
 
+### Segment Discovery
+|Property|Possible Values|Description|Default|
+|--------|---------------|-----------|-------|
+|`druid.announcer.type`|batch or http|Segment discovery method to use. "http" enables discovering segments using HTTP instead of zookeeper.|batch|
+
 ### Others
 
 |Property|Possible Values|Description|Default|

docs/content/configuration/coordinator.md

@@ -38,6 +38,17 @@ The coordinator node uses several of the global configs in [Configuration](../co
 |`druid.coordinator.asOverlord.enabled`|Boolean value for whether this coordinator node should act like an overlord as well. This configuration allows users to simplify a druid cluster by not having to deploy any standalone overlord nodes. If set to true, then overlord console is available at `http://coordinator-host:port/console.html` and be sure to set `druid.coordinator.asOverlord.overlordService` also. See next.|false|
 |`druid.coordinator.asOverlord.overlordService`| Required, if `druid.coordinator.asOverlord.enabled` is `true`. This must be same value as `druid.service` on standalone Overlord nodes and `druid.selectors.indexing.serviceName` on Middle Managers.|NULL|
 
+### Segment Management
+|Property|Possible Values|Description|Default|
+|--------|---------------|-----------|-------|
+|`druid.announcer.type`|batch or http|Segment discovery method to use. "http" enables discovering segments using HTTP instead of zookeeper.|batch|
+|`druid.coordinator.loadqueuepeon.type`|curator or http|Whether to use "http" or "curator" implementation to assign segment loads/drops to historical|curator|
+
+#### Additional config when "http" loadqueuepeon is used
+|Property|Description|Default|
+|--------|-----------|-------|
+|`druid.coordinator.loadqueuepeon.http.batchSize`|Number of segment load/drop requests to batch in one HTTP request. Note that it must be smaller than `druid.segmentCache.numLoadingThreads` config on historical node.|1|
+
 ### Metadata Retrieval
 
 |Property|Description|Default|

server/src/main/java/io/druid/client/BatchServerInventoryView.java

@@ -43,7 +43,9 @@ import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.Executor;
 
 /**
+ * This class is deprecated. Use {@link HttpServerInventoryView} instead.
  */
+@Deprecated
 @ManageLifecycle
 public class BatchServerInventoryView extends AbstractCuratorServerInventoryView<Set<DataSegment>>
     implements FilteredServerInventoryView

server/src/main/java/io/druid/client/SingleServerInventoryView.java

@@ -38,7 +38,9 @@ import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.Executor;
 
 /**
+ * This class is deprecated. Use {@link HttpServerInventoryView} instead.
  */
+@Deprecated
 @ManageLifecycle
 public class SingleServerInventoryView extends AbstractCuratorServerInventoryView<DataSegment> implements FilteredServerInventoryView
 {

server/src/main/java/io/druid/curator/discovery/CuratorServiceAnnouncer.java

@@ -30,8 +30,11 @@ import org.apache.curator.x.discovery.ServiceInstance;
 import java.util.Map;
 
 /**
+ * This class is deprecated, Add service to {@link io.druid.discovery.DruidNodeAnnouncer} node announcement instead.
+ *
  * Uses the Curator Service Discovery recipe to announce services.
  */
+@Deprecated
 public class CuratorServiceAnnouncer implements ServiceAnnouncer
 {
   private static final EmittingLogger log = new EmittingLogger(CuratorServiceAnnouncer.class);

server/src/main/java/io/druid/curator/discovery/CuratorServiceUtils.java

@@ -19,6 +19,10 @@
 
 package io.druid.curator.discovery;
 
+/**
+ * This class is only used by Deprecated classes.
+ */
+@Deprecated
 public class CuratorServiceUtils
 {
   /**

server/src/main/java/io/druid/curator/discovery/NoopServiceAnnouncer.java

@@ -24,6 +24,7 @@ import io.druid.server.DruidNode;
 /**
  * Does nothing.
  */
+@Deprecated
 public class NoopServiceAnnouncer implements ServiceAnnouncer
 {
   @Override

server/src/main/java/io/druid/curator/discovery/ServerDiscoveryFactory.java

@@ -28,7 +28,9 @@ import java.io.IOException;
 import java.util.Collection;
 
 /**
+ * Use {@link io.druid.discovery.DruidNodeDiscovery} for discovery.
  */
+@Deprecated
 public class ServerDiscoveryFactory
 {
   private final ServiceDiscovery<Void> serviceDiscovery;

server/src/main/java/io/druid/curator/discovery/ServerDiscoverySelector.java

@@ -36,7 +36,9 @@ import java.util.Collection;
 import java.util.Collections;
 
 /**
+ * Use {@link io.druid.discovery.DruidNodeDiscovery} for discovery.
  */
+@Deprecated
 public class ServerDiscoverySelector implements DiscoverySelector<Server>
 {
   private static final Logger log = new Logger(ServerDiscoverySelector.class);

server/src/main/java/io/druid/curator/discovery/ServiceAnnouncer.java

@@ -22,9 +22,12 @@ package io.druid.curator.discovery;
 import io.druid.server.DruidNode;
 
 /**
+ * This class is deprecated, Add service to {@link io.druid.discovery.DruidNodeAnnouncer} node announcement instead.
+ *
  * Announces our ability to serve a particular function. Multiple users may announce the same service, in which
  * case they are treated as interchangeable instances of that service.
  */
+@Deprecated
 public interface ServiceAnnouncer
 {
   void announce(DruidNode node);

server/src/main/java/io/druid/curator/inventory/CuratorInventoryManager.java

@@ -43,6 +43,8 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicReference;
 
 /**
+ * This class is deprecated. Use {@link io.druid.client.HttpServerInventoryView} for segment discovery.
+ *
  * An InventoryManager watches updates to inventory on Zookeeper (or some other discovery-like service publishing
  * system).  It is built up on two object types: containers and inventory objects.
  * <p/>
@@ -52,6 +54,7 @@ import java.util.concurrent.atomic.AtomicReference;
  * A Strategy is provided to the constructor of an Inventory manager, this strategy provides all of the
  * object-specific logic to serialize, deserialize, compose and alter the container and inventory objects.
  */
+@Deprecated
 public class CuratorInventoryManager<ContainerClass, InventoryClass>
 {
   private static final Logger log = new Logger(CuratorInventoryManager.class);

server/src/main/java/io/druid/query/lookup/LookupModule.java

@@ -214,6 +214,7 @@ class LookupListeningResource extends ListenerResource
   }
 }
 
+@Deprecated
 class LookupResourceListenerAnnouncer extends ListenerResourceAnnouncer
 {
   @Inject

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

@@ -29,7 +29,9 @@ import io.druid.server.initialization.ZkPathsConfig;
 import org.apache.curator.utils.ZKPaths;
 
 /**
+ * {@link DataSegmentServerAnnouncer} is deprecated.
  */
+@Deprecated
 public class CuratorDataSegmentServerAnnouncer implements DataSegmentServerAnnouncer
 {
   private static final Logger log = new Logger(CuratorDataSegmentServerAnnouncer.class);

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

@@ -20,7 +20,9 @@
 package io.druid.server.coordination;
 
 /**
+ * Use announcement made by {@link io.druid.discovery.DruidNodeAnnouncer}
  */
+@Deprecated
 public interface DataSegmentServerAnnouncer
 {
   void announce();

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

@@ -37,7 +37,9 @@ import org.apache.curator.utils.ZKPaths;
 import java.io.IOException;
 
 /**
+ * Use {@link io.druid.server.coordinator.HttpLoadQueuePeon} for segment load/drops.
  */
+@Deprecated
 public class ZkCoordinator
 {
   private static final EmittingLogger log = new EmittingLogger(ZkCoordinator.class);

server/src/main/java/io/druid/server/coordinator/CuratorLoadQueuePeon.java

@@ -51,7 +51,9 @@ import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicLong;
 
 /**
+ * Use {@link HttpLoadQueuePeon} instead.
  */
+@Deprecated
 public class CuratorLoadQueuePeon extends LoadQueuePeon
 {
   private static final EmittingLogger log = new EmittingLogger(CuratorLoadQueuePeon.class);

server/src/main/java/io/druid/server/listener/announcer/ListenerResourceAnnouncer.java

@@ -31,8 +31,9 @@ import org.apache.curator.utils.ZKPaths;
 import java.nio.ByteBuffer;
 
 /**
- * Announces that there is a particular ListenerResource at the listener_key.
+ * Starting 0.11.0 Coordinator uses announcements made by {@link io.druid.discovery.DruidNodeAnnouncer} .
  */
+@Deprecated
 public abstract class ListenerResourceAnnouncer
 {
   private static final byte[] ANNOUNCE_BYTES = ByteBuffer