Reconcile terminology and method naming to 'used/unused segments'; Rename MetadataSegmentManager to MetadataSegmentsManager

benchmarks/src/main/java/org/apache/druid/server/coordinator/NewestSegmentFirstPolicyBenchmark.java

@@ -23,9 +23,9 @@
 import com.google.common.collect.ImmutableMap;
 import org.apache.druid.client.DataSourcesSnapshot;
 import org.apache.druid.java.util.common.DateTimes;
-import org.apache.druid.server.coordinator.helper.CompactionSegmentIterator;
-import org.apache.druid.server.coordinator.helper.CompactionSegmentSearchPolicy;
-import org.apache.druid.server.coordinator.helper.NewestSegmentFirstPolicy;
+import org.apache.druid.server.coordinator.duty.CompactionSegmentIterator;
+import org.apache.druid.server.coordinator.duty.CompactionSegmentSearchPolicy;
+import org.apache.druid.server.coordinator.duty.NewestSegmentFirstPolicy;
 import org.apache.druid.timeline.DataSegment;
 import org.apache.druid.timeline.VersionedIntervalTimeline;
 import org.apache.druid.timeline.partition.NumberedShardSpec;

docs/content/operations/metrics.md

@@ -211,7 +211,10 @@ These metrics are for the Druid Coordinator and are reset each time the Coordina
 |`segment/unavailable/count`|Number of segments (not including replicas) left to load until segments that should be loaded in the cluster are available for queries.|dataSource.|0|
 |`segment/underReplicated/count`|Number of segments (including replicas) left to load until segments that should be loaded in the cluster are available for queries.|tier, dataSource.|0|
 
-If `emitBalancingStats` is set to `true` in the Coordinator [dynamic configuration](../configuration/index.html#dynamic-configuration), then [log entries](../configuration/logging.html) for class `org.apache.druid.server.coordinator.helper.DruidCoordinatorLogger` will have extra information on balancing decisions.
+If `emitBalancingStats` is set to `true` in the Coordinator [dynamic configuration](
+../configuration/index.html#dynamic-configuration), then [log entries](../configuration/logging.html) for class
+`org.apache.druid.server.coordinator.duty.EmitClusterStatsAndMetrics` will have extra information on balancing
+decisions.
 
 ## General Health
 

indexing-service/src/main/java/org/apache/druid/indexing/common/task/CompactionTask.java

@@ -114,7 +114,7 @@ public class CompactionTask extends AbstractTask
   private static final Logger log = new Logger(CompactionTask.class);
   /**
    * Must be synced with {@link
-   * org.apache.druid.server.coordinator.helper.DruidCoordinatorSegmentCompactor#COMPACTION_TASK_TYPE}.
+   * org.apache.druid.server.coordinator.duty.CompactSegments#COMPACTION_TASK_TYPE}.
    */
   private static final String TYPE = "compact";
 

server/src/main/java/org/apache/druid/client/DataSourcesSnapshot.java

@@ -35,7 +35,7 @@
 import java.util.Map;
 
 /**
- * An immutable snapshot information about used segments and overshadowed segments for
+ * An immutable snapshot of metadata information about used segments and overshadowed segments, coming from
  * {@link org.apache.druid.metadata.SqlSegmentsMetadata}.
  */
 public class DataSourcesSnapshot

server/src/main/java/org/apache/druid/guice/annotations/CoordinatorIndexingServiceHelper.java → server/src/main/java/org/apache/druid/guice/annotations/CoordinatorIndexingServiceDuty.java

@@ -31,6 +31,6 @@
 @BindingAnnotation
 @Target({ElementType.FIELD, ElementType.PARAMETER, ElementType.METHOD})
 @Retention(RetentionPolicy.RUNTIME)
-public @interface CoordinatorIndexingServiceHelper
+public @interface CoordinatorIndexingServiceDuty
 {
 }

server/src/main/java/org/apache/druid/server/coordinator/BalancerStrategy.java

@@ -19,6 +19,7 @@
 
 package org.apache.druid.server.coordinator;
 
+import org.apache.druid.server.coordinator.duty.BalanceSegments;
 import org.apache.druid.timeline.DataSegment;
 
 import javax.annotation.Nullable;
@@ -30,7 +31,7 @@
  * This interface describes the coordinator balancing strategy, which is responsible for making decisions on where
  * to place {@link DataSegment}s on historical servers (described by {@link ServerHolder}). The balancing strategy
  * is used by {@link org.apache.druid.server.coordinator.rules.LoadRule} to assign and drop segments, and by
- * {@link org.apache.druid.server.coordinator.helper.DruidCoordinatorBalancer} to migrate segments between historicals.
+ * {@link BalanceSegments} to migrate segments between historicals.
  */
 public interface BalancerStrategy
 {
@@ -77,7 +78,7 @@ default Iterator<ServerHolder> pickServersToDrop(DataSegment toDropSegment, Navi
 
   /**
    * Add balancing strategy stats during the 'balanceTier' operation of
-   * {@link org.apache.druid.server.coordinator.helper.DruidCoordinatorBalancer} to be included
+   * {@link BalanceSegments} to be included
    * @param tier historical tier being balanced
    * @param stats stats object to add balancing strategy stats to
    * @param serverHolderList servers in tier being balanced

server/src/main/java/org/apache/druid/server/coordinator/CoordinatorDynamicConfig.java

@@ -25,7 +25,7 @@
 import com.google.common.collect.ImmutableSet;
 import org.apache.druid.common.config.JacksonConfigManager;
 import org.apache.druid.java.util.common.IAE;
-import org.apache.druid.server.coordinator.helper.DruidCoordinatorUnusedSegmentsKiller;
+import org.apache.druid.server.coordinator.duty.KillUnusedSegments;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -58,22 +58,22 @@ public class CoordinatorDynamicConfig
   private final int balancerComputeThreads;
   private final boolean emitBalancingStats;
 
-  /** If true {@link DruidCoordinatorUnusedSegmentsKiller} sends kill tasks for unused segments in all data sources. */
+  /** If true {@link KillUnusedSegments} sends kill tasks for unused segments in all data sources. */
   private final boolean killUnusedSegmentsInAllDataSources;
 
   /**
-   * List of specific data sources for which kill tasks are sent in {@link DruidCoordinatorUnusedSegmentsKiller}.
+   * List of specific data sources for which kill tasks are sent in {@link KillUnusedSegments}.
    */
   private final Set<String> specificDataSourcesToKillUnusedSegmentsIn;
   private final Set<String> decommissioningNodes;
   private final int decommissioningMaxPercentOfMaxSegmentsToMove;
 
   /**
    * Stale pending segments belonging to the data sources in this list are not killed by {@link
-   * DruidCoordinatorKillStalePendingSegments}. In other words, segments in these data sources are "protected".
+   * KillStalePendingSegments}. In other words, segments in these data sources are "protected".
    *
    * Pending segments are considered "stale" when their created_time is older than {@link
-   * DruidCoordinatorKillStalePendingSegments#KEEP_PENDING_SEGMENTS_OFFSET} from now.
+   * KillStalePendingSegments#KEEP_PENDING_SEGMENTS_OFFSET} from now.
    */
   private final Set<String> dataSourcesToNotKillStalePendingSegmentsIn;