MINOR: Delete task-level commit sensor (#14677)

The task-level commit metrics were removed without deprecation in KIP-447 and the corresponding PR #8218. However, we forgot to update the docs and to remove the code that creates the task-level commit sensor.
This PR removes the task-level commit metrics from the docs and removes the code that creates the task-level commit sensor. The code was effectively dead since it was only used in tests.

Reviewers: Guozhang Wang <wangguoz@gmail.com>, Matthias J. Sax <matthias@confluent.io>

docs/ops.html

@@ -2956,26 +2956,6 @@ active-process-ratio metrics which have a recording level of <code>info</code>:
         <td>The total number of processed records across all source processor nodes of this task.</td>
         <td>kafka.streams:type=stream-task-metrics,thread-id=([-.\w]+),task-id=([-.\w]+)</td>
       </tr>
-      <tr>
-        <td>commit-latency-avg</td>
-        <td>The average execution time in ns, for committing.</td>
-        <td>kafka.streams:type=stream-task-metrics,thread-id=([-.\w]+),task-id=([-.\w]+)</td>
-      </tr>
-      <tr>
-        <td>commit-latency-max</td>
-        <td>The maximum execution time in ns, for committing.</td>
-        <td>kafka.streams:type=stream-task-metrics,thread-id=([-.\w]+),task-id=([-.\w]+)</td>
-      </tr>
-      <tr>
-        <td>commit-rate</td>
-        <td>The average number of commit calls per second.</td>
-        <td>kafka.streams:type=stream-task-metrics,thread-id=([-.\w]+),task-id=([-.\w]+)</td>
-      </tr>
-      <tr>
-        <td>commit-total</td>
-        <td>The total number of commit calls.</td>
-        <td>kafka.streams:type=stream-task-metrics,thread-id=([-.\w]+),task-id=([-.\w]+)</td>
-      </tr>
       <tr>
         <td>record-lateness-avg</td>
         <td>The average observed lateness of records (stream time - record timestamp).</td>

streams/src/main/java/org/apache/kafka/streams/processor/internals/metrics/TaskMetrics.java

@@ -41,12 +41,6 @@ public class TaskMetrics {
     private static final String RATE_DESCRIPTION_SUFFIX = " per second";
     private static final String ACTIVE_TASK_PREFIX = "active-";
 
-    private static final String COMMIT = "commit";
-    private static final String COMMIT_DESCRIPTION = "calls to commit";
-    private static final String COMMIT_TOTAL_DESCRIPTION = TOTAL_DESCRIPTION + COMMIT_DESCRIPTION;
-    private static final String COMMIT_RATE_DESCRIPTION =
-        RATE_DESCRIPTION_PREFIX + COMMIT_DESCRIPTION + RATE_DESCRIPTION_SUFFIX;
-
     private static final String PUNCTUATE = "punctuate";
     private static final String PUNCTUATE_DESCRIPTION = "calls to punctuate";
     private static final String PUNCTUATE_TOTAL_DESCRIPTION = TOTAL_DESCRIPTION + PUNCTUATE_DESCRIPTION;
@@ -191,22 +185,6 @@ public class TaskMetrics {
         );
     }
 
-    public static Sensor commitSensor(final String threadId,
-                                      final String taskId,
-                                      final StreamsMetricsImpl streamsMetrics,
-                                      final Sensor... parentSensor) {
-        return invocationRateAndCountSensor(
-            threadId,
-            taskId,
-            COMMIT,
-            COMMIT_RATE_DESCRIPTION,
-            COMMIT_TOTAL_DESCRIPTION,
-            Sensor.RecordingLevel.DEBUG,
-            streamsMetrics,
-            parentSensor
-        );
-    }
-
     public static Sensor restoreSensor(final String threadId,
                                        final String taskId,
                                        final StreamsMetricsImpl streamsMetrics,

streams/src/main/java/org/apache/kafka/streams/processor/internals/metrics/ThreadMetrics.java

@@ -27,8 +27,6 @@ import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetric
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.RATE_SUFFIX;
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.RATIO_SUFFIX;
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.RECORDS_SUFFIX;
-import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.ROLLUP_VALUE;
-import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.TASK_LEVEL_GROUP;
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.THREAD_LEVEL_GROUP;
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.TOTAL_DESCRIPTION;
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.addAvgAndMaxToSensor;
@@ -78,10 +76,6 @@ public class ThreadMetrics {
     private static final String PUNCTUATE_RATE_DESCRIPTION = RATE_DESCRIPTION + PUNCTUATE_DESCRIPTION;
     private static final String PUNCTUATE_AVG_LATENCY_DESCRIPTION = "The average punctuate latency";
     private static final String PUNCTUATE_MAX_LATENCY_DESCRIPTION = "The maximum punctuate latency";
-    private static final String COMMIT_OVER_TASKS_DESCRIPTION =
-        "calls to commit over all tasks assigned to one stream thread";
-    private static final String COMMIT_OVER_TASKS_TOTAL_DESCRIPTION = TOTAL_DESCRIPTION + COMMIT_OVER_TASKS_DESCRIPTION;
-    private static final String COMMIT_OVER_TASKS_RATE_DESCRIPTION = RATE_DESCRIPTION + COMMIT_OVER_TASKS_DESCRIPTION;
     private static final String PROCESS_RATIO_DESCRIPTION =
         "The fraction of time the thread spent on processing active tasks";
     private static final String PUNCTUATE_RATIO_DESCRIPTION =
@@ -225,22 +219,6 @@ public class ThreadMetrics {
         );
     }
 
-    public static Sensor commitOverTasksSensor(final String threadId,
-                                               final StreamsMetricsImpl streamsMetrics) {
-        final Sensor commitOverTasksSensor =
-            streamsMetrics.threadLevelSensor(threadId, COMMIT, Sensor.RecordingLevel.DEBUG);
-        final Map<String, String> tagMap = streamsMetrics.taskLevelTagMap(threadId, ROLLUP_VALUE);
-        addInvocationRateAndCountToSensor(
-            commitOverTasksSensor,
-            TASK_LEVEL_GROUP,
-            tagMap,
-            COMMIT,
-            COMMIT_OVER_TASKS_RATE_DESCRIPTION,
-            COMMIT_OVER_TASKS_TOTAL_DESCRIPTION
-        );
-        return commitOverTasksSensor;
-    }
-
     public static Sensor processRatioSensor(final String threadId,
                                             final StreamsMetricsImpl streamsMetrics) {
         final Sensor sensor =

streams/src/test/java/org/apache/kafka/streams/processor/internals/metrics/TaskMetricsTest.java

@@ -177,30 +177,6 @@ public class TaskMetricsTest {
         }
     }
 
-    @Test
-    public void shouldGetCommitSensor() {
-        final String operation = "commit";
-        final String totalDescription = "The total number of calls to commit";
-        final String rateDescription = "The average number of calls to commit per second";
-        when(streamsMetrics.taskLevelSensor(THREAD_ID, TASK_ID, operation, RecordingLevel.DEBUG)).thenReturn(expectedSensor);
-        when(streamsMetrics.taskLevelTagMap(THREAD_ID, TASK_ID)).thenReturn(tagMap);
-
-        try (final MockedStatic<StreamsMetricsImpl> streamsMetricsStaticMock = mockStatic(StreamsMetricsImpl.class)) {
-            final Sensor sensor = TaskMetrics.commitSensor(THREAD_ID, TASK_ID, streamsMetrics);
-            streamsMetricsStaticMock.verify(
-                () -> StreamsMetricsImpl.addInvocationRateAndCountToSensor(
-                    expectedSensor,
-                    TASK_LEVEL_GROUP,
-                    tagMap,
-                    operation,
-                    rateDescription,
-                    totalDescription
-                )
-            );
-            assertThat(sensor, is(expectedSensor));
-        }
-    }
-
     @Test
     public void shouldGetEnforcedProcessingSensor() {
         final String operation = "enforced-processing";

streams/src/test/java/org/apache/kafka/streams/processor/internals/metrics/ThreadMetricsTest.java

@@ -35,7 +35,6 @@ import org.mockito.MockedStatic;
 
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.LATENCY_SUFFIX;
 import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.RATE_SUFFIX;
-import static org.apache.kafka.streams.processor.internals.metrics.StreamsMetricsImpl.ROLLUP_VALUE;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
@@ -43,7 +42,6 @@ public class ThreadMetricsTest {
 
     private static final String THREAD_ID = "thread-id";
     private static final String THREAD_LEVEL_GROUP = "stream-thread-metrics";
-    private static final String TASK_LEVEL_GROUP = "stream-task-metrics";
 
     private final Sensor expectedSensor = mock(Sensor.class);
     private final StreamsMetricsImpl streamsMetrics = mock(StreamsMetricsImpl.class);
@@ -287,32 +285,6 @@ public class ThreadMetricsTest {
         }
     }
 
-    @Test
-    public void shouldGetCommitOverTasksSensor() {
-        final String operation = "commit";
-        final String totalDescription =
-            "The total number of calls to commit over all tasks assigned to one stream thread";
-        final String rateDescription =
-            "The average per-second number of calls to commit over all tasks assigned to one stream thread";
-        when(streamsMetrics.threadLevelSensor(THREAD_ID, operation, RecordingLevel.DEBUG)).thenReturn(expectedSensor);
-        when(streamsMetrics.taskLevelTagMap(THREAD_ID, ROLLUP_VALUE)).thenReturn(tagMap);
-
-        try (final MockedStatic<StreamsMetricsImpl> streamsMetricsStaticMock = mockStatic(StreamsMetricsImpl.class)) {
-            final Sensor sensor = ThreadMetrics.commitOverTasksSensor(THREAD_ID, streamsMetrics);
-            streamsMetricsStaticMock.verify(
-                () -> StreamsMetricsImpl.addInvocationRateAndCountToSensor(
-                    expectedSensor,
-                    TASK_LEVEL_GROUP,
-                    tagMap,
-                    operation,
-                    rateDescription,
-                    totalDescription
-                )
-            );
-            assertThat(sensor, is(expectedSensor));
-        }
-    }
-
     @Test
     public void shouldGetPunctuateSensor() {
         final String operation = "punctuate";
@@ -371,6 +343,8 @@ public class ThreadMetricsTest {
             assertThat(sensor, is(expectedSensor));
         }
     }
+
+    @Test
     public void shouldGetCreateTaskSensor() {
         final String operation = "task-created";
         final String totalDescription = "The total number of newly created tasks";