Throttle empty subscription poll logs

iotdb-client/subscription/src/main/java/org/apache/iotdb/session/subscription/consumer/base/AbstractSubscriptionPullConsumer.java

@@ -41,6 +41,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.OptionalLong;
 import java.util.Properties;
 import java.util.Queue;
 import java.util.Set;
@@ -83,6 +84,8 @@ public abstract class AbstractSubscriptionPullConsumer extends AbstractSubscript
 
   private SortedMap<Long, Set<SubscriptionCommitContext>> uncommittedCommitContexts;
 
+  private final EmptyPollLogThrottler emptyPollLogThrottler = new EmptyPollLogThrottler();
+
   private final AtomicBoolean isClosed = new AtomicBoolean(true);
 
   @Override
@@ -137,6 +140,7 @@ protected synchronized void open() throws SubscriptionException {
 
     // set isClosed to false before submitting workers
     isClosed.set(false);
+    emptyPollLogThrottler.reset();
 
     // submit auto poll worker if enabling auto commit
     if (autoCommit) {
@@ -237,11 +241,16 @@ protected List<SubscriptionMessage> poll(final Set<String> topicNames, final lon
 
     final List<SubscriptionMessage> messages = multiplePoll(parsedTopicNames, timeoutMs);
     if (messages.isEmpty() && processors.isEmpty()) {
-      LOGGER.info(
-          "SubscriptionPullConsumer {} poll empty message from topics {} after {} millisecond(s)",
-          this,
-          CollectionUtils.getLimitedString(parsedTopicNames, 32),
-          timeoutMs);
+      final OptionalLong consecutiveEmptyPollCount =
+          emptyPollLogThrottler.markEmptyPollAndMaybeGetCount();
+      if (consecutiveEmptyPollCount.isPresent()) {
+        LOGGER.info(
+            "SubscriptionPullConsumer {} poll empty message from topics {} after {} millisecond(s), consecutive empty polls: {}",
+            this,
+            CollectionUtils.getLimitedString(parsedTopicNames, 32),
+            timeoutMs,
+            consecutiveEmptyPollCount.getAsLong());
+      }
       return messages;
     }
 
@@ -260,6 +269,7 @@ protected List<SubscriptionMessage> poll(final Set<String> topicNames, final lon
       return processed;
     }
 
+    emptyPollLogThrottler.reset();
     trackAutoCommitMessages(processed);
 
     return processed;

iotdb-client/subscription/src/main/java/org/apache/iotdb/session/subscription/consumer/base/AbstractSubscriptionPushConsumer.java

@@ -37,6 +37,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.OptionalLong;
 import java.util.Properties;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -62,6 +63,8 @@ public abstract class AbstractSubscriptionPushConsumer extends AbstractSubscript
   private final long autoPollIntervalMs;
   private final long autoPollTimeoutMs;
 
+  private final EmptyPollLogThrottler emptyPollLogThrottler = new EmptyPollLogThrottler();
+
   private final AtomicBoolean isClosed = new AtomicBoolean(true);
 
   protected AbstractSubscriptionPushConsumer(
@@ -128,6 +131,7 @@ protected synchronized void open() throws SubscriptionException {
 
     // set isClosed to false before submitting workers
     isClosed.set(false);
+    emptyPollLogThrottler.reset();
 
     // submit auto poll worker
     submitAutoPollWorker();
@@ -198,14 +202,20 @@ public void run() {
               return type == SubscriptionMessageType.WATERMARK.getType();
             });
         if (messages.isEmpty()) {
-          LOGGER.info(
-              "SubscriptionPushConsumer {} poll empty message from topics {} after {} millisecond(s)",
-              this,
-              CollectionUtils.getLimitedString(subscribedTopics.keySet(), 32),
-              autoPollTimeoutMs);
+          final OptionalLong consecutiveEmptyPollCount =
+              emptyPollLogThrottler.markEmptyPollAndMaybeGetCount();
+          if (consecutiveEmptyPollCount.isPresent()) {
+            LOGGER.info(
+                "SubscriptionPushConsumer {} poll empty message from topics {} after {} millisecond(s), consecutive empty polls: {}",
+                AbstractSubscriptionPushConsumer.this,
+                CollectionUtils.getLimitedString(subscribedTopics.keySet(), 32),
+                autoPollTimeoutMs,
+                consecutiveEmptyPollCount.getAsLong());
+          }
           return;
         }
 
+        emptyPollLogThrottler.reset();
         if (ackStrategy.equals(AckStrategy.BEFORE_CONSUME)) {
           ack(messages);
         }

iotdb-client/subscription/src/main/java/org/apache/iotdb/session/subscription/consumer/base/EmptyPollLogThrottler.java

@@ -0,0 +1,62 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iotdb.session.subscription.consumer.base;
+
+import java.util.OptionalLong;
+import java.util.concurrent.TimeUnit;
+import java.util.function.LongSupplier;
+
+final class EmptyPollLogThrottler {
+
+  private static final long DEFAULT_LOG_INTERVAL_NANOS = TimeUnit.MINUTES.toNanos(1);
+
+  private final long logIntervalNanos;
+  private final LongSupplier ticker;
+
+  private long consecutiveEmptyPollCount;
+  private long lastLogTimeNanos;
+  private boolean hasLoggedEmptyPoll;
+
+  EmptyPollLogThrottler() {
+    this(DEFAULT_LOG_INTERVAL_NANOS, System::nanoTime);
+  }
+
+  EmptyPollLogThrottler(final long logIntervalNanos, final LongSupplier ticker) {
+    this.logIntervalNanos = Math.max(logIntervalNanos, 1);
+    this.ticker = ticker;
+  }
+
+  synchronized OptionalLong markEmptyPollAndMaybeGetCount() {
+    consecutiveEmptyPollCount++;
+    final long currentTimeNanos = ticker.getAsLong();
+    if (!hasLoggedEmptyPoll || currentTimeNanos - lastLogTimeNanos >= logIntervalNanos) {
+      hasLoggedEmptyPoll = true;
+      lastLogTimeNanos = currentTimeNanos;
+      return OptionalLong.of(consecutiveEmptyPollCount);
+    }
+    return OptionalLong.empty();
+  }
+
+  synchronized void reset() {
+    consecutiveEmptyPollCount = 0;
+    lastLogTimeNanos = 0;
+    hasLoggedEmptyPoll = false;
+  }
+}

iotdb-client/subscription/src/test/java/org/apache/iotdb/session/subscription/consumer/base/EmptyPollLogThrottlerTest.java

@@ -0,0 +1,63 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iotdb.session.subscription.consumer.base;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.OptionalLong;
+import java.util.concurrent.atomic.AtomicLong;
+
+public class EmptyPollLogThrottlerTest {
+
+  @Test
+  public void testThrottleConsecutiveEmptyPollLogs() {
+    final AtomicLong ticker = new AtomicLong();
+    final EmptyPollLogThrottler throttler = new EmptyPollLogThrottler(100, ticker::get);
+
+    OptionalLong logCount = throttler.markEmptyPollAndMaybeGetCount();
+    Assert.assertTrue(logCount.isPresent());
+    Assert.assertEquals(1, logCount.getAsLong());
+
+    ticker.addAndGet(99);
+    logCount = throttler.markEmptyPollAndMaybeGetCount();
+    Assert.assertFalse(logCount.isPresent());
+
+    ticker.incrementAndGet();
+    logCount = throttler.markEmptyPollAndMaybeGetCount();
+    Assert.assertTrue(logCount.isPresent());
+    Assert.assertEquals(3, logCount.getAsLong());
+  }
+
+  @Test
+  public void testResetMakesNextEmptyPollLoggable() {
+    final AtomicLong ticker = new AtomicLong();
+    final EmptyPollLogThrottler throttler = new EmptyPollLogThrottler(100, ticker::get);
+
+    Assert.assertTrue(throttler.markEmptyPollAndMaybeGetCount().isPresent());
+    Assert.assertFalse(throttler.markEmptyPollAndMaybeGetCount().isPresent());
+
+    throttler.reset();
+
+    final OptionalLong logCount = throttler.markEmptyPollAndMaybeGetCount();
+    Assert.assertTrue(logCount.isPresent());
+    Assert.assertEquals(1, logCount.getAsLong());
+  }
+}