Remove index_realtime and index_realtime_appenderator tasks.

index_realtime tasks were removed from the documentation in apache#13107. Even
at that time, they weren't really documented per se— just mentioned. They
existed solely to support Tranquility, which is an obsolete ingestion
method that predates migration of Druid to ASF and is no longer being
maintained. Tranquility docs were also de-linked from the sidebars and
the other doc pages in apache#11134. Only a stub remains, so people with
links to the page can see that it's no longer recommended.

index_realtime_appenderator tasks existed in the code base, but were
never documented, nor as far as I am aware were they used for any purpose.

This patch removes both task types completely, as well as removes all
supporting code that was otherwise unused. It also updates the stub
doc for Tranquility to be firmer that it is not compatible. (Previously,
the stub doc said it wasn't recommended, and pointed out that it is
built against an ancient 0.9.2 version of Druid.)

extensions-core/kafka-indexing-service/src/test/java/org/apache/druid/indexing/kafka/KafkaIndexTaskTest.java

@@ -367,7 +367,7 @@ public void testRunAfterDataInserted() throws Exception
     // Wait for task to exit
     Assert.assertEquals(TaskState.SUCCESS, future.get().getStatusCode());
     verifyTaskMetrics(task, RowMeters.with().bytes(getTotalSizeOfRecords(2, 5)).totalProcessed(3));
-    Assert.assertTrue(task.getRunner().getFireDepartmentMetrics().isProcessingDone());
+    Assert.assertTrue(task.getRunner().getSegmentGenerationMetrics().isProcessingDone());
 
     // Check published metadata and segments in deep storage
     assertEqualsExceptVersion(
@@ -505,7 +505,7 @@ public void testRunAfterDataInsertedWithLegacyParser() throws Exception
     // Wait for task to exit
     Assert.assertEquals(TaskState.SUCCESS, future.get().getStatusCode());
     verifyTaskMetrics(task, RowMeters.with().bytes(getTotalSizeOfRecords(2, 5)).totalProcessed(3));
-    Assert.assertTrue(task.getRunner().getFireDepartmentMetrics().isProcessingDone());
+    Assert.assertTrue(task.getRunner().getSegmentGenerationMetrics().isProcessingDone());
 
     // Check published metadata and segments in deep storage
     assertEqualsExceptVersion(
@@ -554,7 +554,7 @@ public void testRunBeforeDataInserted() throws Exception
     // Wait for task to exit
     Assert.assertEquals(TaskState.SUCCESS, future.get().getStatusCode());
     verifyTaskMetrics(task, RowMeters.with().bytes(getTotalSizeOfRecords(2, 5)).totalProcessed(3));
-    Assert.assertTrue(task.getRunner().getFireDepartmentMetrics().isProcessingDone());
+    Assert.assertTrue(task.getRunner().getSegmentGenerationMetrics().isProcessingDone());
 
     // Check published metadata and segments in deep storage
     assertEqualsExceptVersion(

extensions-core/kafka-indexing-service/src/test/java/org/apache/druid/indexing/kafka/supervisor/KafkaSupervisorTest.java

@@ -40,7 +40,7 @@
 import org.apache.druid.indexer.TaskStatus;
 import org.apache.druid.indexing.common.TaskInfoProvider;
 import org.apache.druid.indexing.common.TestUtils;
-import org.apache.druid.indexing.common.task.RealtimeIndexTask;
+import org.apache.druid.indexing.common.task.NoopTask;
 import org.apache.druid.indexing.common.task.Task;
 import org.apache.druid.indexing.kafka.KafkaConsumerConfigs;
 import org.apache.druid.indexing.kafka.KafkaDataSourceMetadata;
@@ -89,9 +89,7 @@
 import org.apache.druid.segment.incremental.ParseExceptionReport;
 import org.apache.druid.segment.incremental.RowIngestionMetersFactory;
 import org.apache.druid.segment.indexing.DataSchema;
-import org.apache.druid.segment.indexing.RealtimeIOConfig;
 import org.apache.druid.segment.indexing.granularity.UniformGranularitySpec;
-import org.apache.druid.segment.realtime.FireDepartment;
 import org.apache.druid.server.metrics.NoopServiceEmitter;
 import org.apache.druid.server.security.Action;
 import org.apache.druid.server.security.Resource;
@@ -983,15 +981,13 @@ public void testDontKillTasksWithMismatchedType() throws Exception
     addSomeEvents(1);
 
     // non KafkaIndexTask (don't kill)
-    Task id2 = new RealtimeIndexTask(
+    Task id2 = new NoopTask(
         "id2",
         null,
-        new FireDepartment(
-            dataSchema,
-            new RealtimeIOConfig(null, null),
-            null
-        ),
-        null
+        dataSchema.getDataSource(),
+        100,
+        100,
+        ImmutableMap.of()
     );
 
     List<Task> existingTasks = ImmutableList.of(id2);

extensions-core/kinesis-indexing-service/src/test/java/org/apache/druid/indexing/kinesis/supervisor/KinesisSupervisorTest.java

@@ -37,7 +37,7 @@
 import org.apache.druid.indexer.TaskStatus;
 import org.apache.druid.indexing.common.TaskInfoProvider;
 import org.apache.druid.indexing.common.TestUtils;
-import org.apache.druid.indexing.common.task.RealtimeIndexTask;
+import org.apache.druid.indexing.common.task.NoopTask;
 import org.apache.druid.indexing.common.task.Task;
 import org.apache.druid.indexing.kinesis.KinesisDataSourceMetadata;
 import org.apache.druid.indexing.kinesis.KinesisIndexTask;
@@ -85,9 +85,7 @@
 import org.apache.druid.segment.TestHelper;
 import org.apache.druid.segment.incremental.RowIngestionMetersFactory;
 import org.apache.druid.segment.indexing.DataSchema;
-import org.apache.druid.segment.indexing.RealtimeIOConfig;
 import org.apache.druid.segment.indexing.granularity.UniformGranularitySpec;
-import org.apache.druid.segment.realtime.FireDepartment;
 import org.apache.druid.server.metrics.NoopServiceEmitter;
 import org.apache.druid.server.security.Action;
 import org.apache.druid.server.security.Resource;
@@ -942,15 +940,13 @@ public void testDontKillTasksWithMismatchedType() throws Exception
     EasyMock.expectLastCall().anyTimes();
 
     // non KinesisIndexTask (don't kill)
-    Task id2 = new RealtimeIndexTask(
+    Task id2 = new NoopTask(
         "id2",
         null,
-        new FireDepartment(
-            dataSchema,
-            new RealtimeIOConfig(null, null),
-            null
-        ),
-        null
+        dataSchema.getDataSource(),
+        100,
+        100,
+        ImmutableMap.of()
     );
 
     List<Task> existingTasks = ImmutableList.of(id2);

extensions-core/multi-stage-query/src/main/java/org/apache/druid/msq/counters/SegmentGeneratorMetricsWrapper.java

@@ -20,15 +20,15 @@
 package org.apache.druid.msq.counters;
 
 import org.apache.druid.msq.indexing.processor.SegmentGeneratorFrameProcessor;
-import org.apache.druid.segment.realtime.FireDepartmentMetrics;
+import org.apache.druid.segment.realtime.SegmentGenerationMetrics;
 
 /**
- * Wrapper around {@link FireDepartmentMetrics} which updates the progress counters while updating its metrics. This
+ * Wrapper around {@link SegmentGenerationMetrics} which updates the progress counters while updating its metrics. This
  * is necessary as the {@link org.apache.druid.segment.realtime.appenderator.BatchAppenderator} used by the
  * {@link SegmentGeneratorFrameProcessor} is not part of the MSQ extension, and hence,
  * cannot update the counters used in MSQ reports as it persists and pushes segments to deep storage.
  */
-public class SegmentGeneratorMetricsWrapper extends FireDepartmentMetrics
+public class SegmentGeneratorMetricsWrapper extends SegmentGenerationMetrics
 {
   private final SegmentGenerationProgressCounter segmentGenerationProgressCounter;
 

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

@@ -19,46 +19,34 @@
 
 package org.apache.druid.indexing.common;
 
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import org.apache.druid.indexing.common.stats.TaskRealtimeMetricsMonitor;
 import org.apache.druid.indexing.common.task.Task;
 import org.apache.druid.query.DruidMetrics;
 import org.apache.druid.segment.incremental.RowIngestionMeters;
-import org.apache.druid.segment.realtime.FireDepartment;
-import org.apache.druid.segment.realtime.RealtimeMetricsMonitor;
+import org.apache.druid.segment.realtime.SegmentGenerationMetrics;
 
 public class TaskRealtimeMetricsMonitorBuilder
 {
   private TaskRealtimeMetricsMonitorBuilder()
   {
   }
 
-  public static RealtimeMetricsMonitor build(Task task, FireDepartment fireDepartment)
-  {
-    return new RealtimeMetricsMonitor(
-        ImmutableList.of(fireDepartment),
-        ImmutableMap.of(
-            DruidMetrics.TASK_ID, new String[]{task.getId()},
-            DruidMetrics.TASK_TYPE, new String[]{task.getType()}
-        )
-    );
-  }
-
   public static TaskRealtimeMetricsMonitor build(
       Task task,
-      FireDepartment fireDepartment,
+      SegmentGenerationMetrics metrics,
       RowIngestionMeters meters
   )
   {
     return new TaskRealtimeMetricsMonitor(
-        fireDepartment,
+        metrics,
         meters,
         ImmutableMap.of(
+            DruidMetrics.DATASOURCE, new String[]{task.getDataSource()},
             DruidMetrics.TASK_ID, new String[]{task.getId()},
             DruidMetrics.TASK_TYPE, new String[]{task.getType()},
             DruidMetrics.GROUP_ID, new String[]{task.getGroupId()}
-            ),
+        ),
         task.getContextValue(DruidMetrics.TAGS)
     );
   }