get pending/schedule/processing message count

rqueue-core/src/main/java/com/github/sonus21/rqueue/config/RqueueListenerBaseConfig.java

@@ -28,6 +28,7 @@
 import com.github.sonus21.rqueue.core.impl.RqueueMessageTemplateImpl;
 import com.github.sonus21.rqueue.dao.RqueueStringDao;
 import com.github.sonus21.rqueue.dao.impl.RqueueStringDaoImpl;
+import com.github.sonus21.rqueue.metrics.RqueueQueueMetrics;
 import com.github.sonus21.rqueue.utils.RedisUtils;
 import com.github.sonus21.rqueue.web.view.DateTimeFunction;
 import com.github.sonus21.rqueue.web.view.DeadLetterQueuesFunction;
@@ -186,4 +187,10 @@ public JtwigViewResolver rqueueViewResolver() {
     viewResolver.setSuffix(".html");
     return viewResolver;
   }
+
+  @Bean
+  public RqueueQueueMetrics rqueueQueueMetrics(
+      RqueueRedisTemplate<String> stringRqueueRedisTemplate) {
+    return new RqueueQueueMetrics(stringRqueueRedisTemplate);
+  }
 }

rqueue-core/src/main/java/com/github/sonus21/rqueue/metrics/RqueueQueueMetrics.java

@@ -0,0 +1,82 @@
+/*
+ *  Copyright 2021 Sonu Kumar
+ *
+ *  Licensed 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
+ *
+ *         https://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 com.github.sonus21.rqueue.metrics;
+
+import com.github.sonus21.rqueue.common.RqueueRedisTemplate;
+import com.github.sonus21.rqueue.core.EndpointRegistry;
+import com.github.sonus21.rqueue.exception.QueueDoesNotExist;
+import com.github.sonus21.rqueue.listener.QueueDetail;
+
+/**
+ * This class reports queue message counter.
+ *
+ * <p>Count can be sent to some monitoring tool like Prometheus, influx db etc
+ */
+public class RqueueQueueMetrics {
+
+  private final RqueueRedisTemplate<String> redisTemplate;
+
+  public RqueueQueueMetrics(RqueueRedisTemplate<String> redisTemplate) {
+    this.redisTemplate = redisTemplate;
+  }
+
+  /**
+   * Get number of messages waiting for consumption
+   *
+   * @param queue queue name
+   * @return -1 if queue is not registered otherwise message count
+   */
+  public long getPendingMessageCount(String queue) {
+    try {
+      QueueDetail queueDetail = EndpointRegistry.get(queue);
+      return redisTemplate.getListSize(queueDetail.getQueueName());
+    } catch (QueueDoesNotExist e) {
+      return -1;
+    }
+  }
+
+  /**
+   * Get number of messages waiting in delayed queue, these messages would move to pending queue as
+   * soon as the scheduled time is reach.
+   *
+   * @param queue queue name
+   * @return -1 if queue is not registered otherwise message count
+   */
+  public long getScheduledMessageCount(String queue) {
+    try {
+      QueueDetail queueDetail = EndpointRegistry.get(queue);
+      return redisTemplate.getZsetSize(queueDetail.getDelayedQueueName());
+    } catch (QueueDoesNotExist e) {
+      return -1;
+    }
+  }
+
+  /**
+   * Get number of messages those are currently being processed
+   *
+   * @param queue queue name
+   * @return -1 if queue is not registered otherwise message count
+   */
+  public long getProcessingMessageCount(String queue) {
+    try {
+      QueueDetail queueDetail = EndpointRegistry.get(queue);
+      return redisTemplate.getZsetSize(queueDetail.getProcessingQueueName());
+    } catch (QueueDoesNotExist e) {
+      return -1;
+    }
+  }
+}

rqueue-spring-boot-starter/src/test/java/com/github/sonus21/rqueue/spring/boot/tests/integration/BootMetricsTest.java

@@ -57,4 +57,9 @@ void metricStatus() throws TimedOutException {
   void countStatusTest() throws TimedOutException {
     this.verifyCountStatus();
   }
+
+  @Test
+  void messageCount() throws TimedOutException {
+    verifyQueueMessageCount();
+  }
 }

rqueue-spring-common-test/src/main/java/com/github/sonus21/rqueue/test/tests/MetricTest.java

@@ -19,18 +19,26 @@
 import static com.github.sonus21.rqueue.utils.TimeoutUtils.waitFor;
 import static com.google.common.collect.Lists.newArrayList;
 
+import com.github.sonus21.rqueue.core.EndpointRegistry;
 import com.github.sonus21.rqueue.exception.TimedOutException;
+import com.github.sonus21.rqueue.listener.QueueDetail;
+import com.github.sonus21.rqueue.metrics.RqueueQueueMetrics;
 import com.github.sonus21.rqueue.test.common.SpringTestBase;
 import com.github.sonus21.rqueue.test.dto.Email;
 import com.github.sonus21.rqueue.test.dto.Job;
 import com.github.sonus21.rqueue.test.dto.Notification;
 import com.github.sonus21.rqueue.utils.Constants;
+import com.github.sonus21.rqueue.utils.TimeoutUtils;
 import io.micrometer.core.instrument.MeterRegistry;
 import java.time.Instant;
 import org.springframework.beans.factory.annotation.Autowired;
 
 public abstract class MetricTest extends SpringTestBase {
-  @Autowired protected MeterRegistry meterRegistry;
+
+  @Autowired
+  protected MeterRegistry meterRegistry;
+  @Autowired
+  protected RqueueQueueMetrics rqueueQueueMetrics;
 
   protected void verifyDelayedQueueStatus() throws TimedOutException {
     long maxDelay = 0;
@@ -141,12 +149,25 @@ protected void verifyCountStatus() throws TimedOutException {
     waitFor(
         () ->
             meterRegistry
-                    .get("failure.count")
-                    .tags("rqueue", "test")
-                    .tags("queue", emailQueue)
-                    .counter()
-                    .count()
+                .get("failure.count")
+                .tags("rqueue", "test")
+                .tags("queue", emailQueue)
+                .counter()
+                .count()
                 == 0,
         "stats collection");
   }
+
+  protected void verifyQueueMessageCount() throws TimedOutException {
+    QueueDetail queueDetail = EndpointRegistry.get(notificationQueue);
+    enqueue(queueDetail.getQueueName(), i -> Notification.newInstance(), 1000);
+    enqueueIn(queueDetail.getDelayedQueueName(), i -> Notification.newInstance(), i -> 30_000L,
+        100);
+    TimeoutUtils.waitFor(() -> rqueueQueueMetrics.getProcessingMessageCount(notificationQueue) > 0,
+        "at least one message in processing");
+    TimeoutUtils.waitFor(() -> rqueueQueueMetrics.getScheduledMessageCount(notificationQueue) > 0,
+        "at least one message in scheduled queue");
+    TimeoutUtils.waitFor(() -> rqueueQueueMetrics.getPendingMessageCount(notificationQueue) > 0,
+        "at least one message in pending queue");
+  }
 }