Add attemptDequeue span to marqs

More telemetry to figure out why dequeuing is slow

Author: matt-aitken

apps/webapp/app/v3/marqs/index.server.ts

@@ -589,48 +589,74 @@ export class MarQS {
           for (const messageQueue of env.queues) {
             attemptedQueues++;
 
-            try {
-              const messageData = await this.#callDequeueMessage({
-                messageQueue,
-                parentQueue,
-              });
-
-              if (!messageData) {
-                continue; // Try next queue if no message was dequeued
+            const result = await this.#trace(
+              "attemptDequeue",
+              async (innerSpan) => {
+                try {
+                  innerSpan.setAttributes({
+                    [SemanticAttributes.QUEUE]: messageQueue,
+                    [SemanticAttributes.PARENT_QUEUE]: parentQueue,
+                  });
+
+                  const messageData = await this.#callDequeueMessage({
+                    messageQueue,
+                    parentQueue,
+                  });
+
+                  if (!messageData) {
+                    return null; // Try next queue if no message was dequeued
+                  }
+
+                  const message = await this.readMessage(messageData.messageId);
+
+                  if (message) {
+                    const attributes = {
+                      [SEMATTRS_MESSAGE_ID]: message.messageId,
+                      [SemanticAttributes.QUEUE]: message.queue,
+                      [SemanticAttributes.MESSAGE_ID]: message.messageId,
+                      [SemanticAttributes.CONCURRENCY_KEY]: message.concurrencyKey,
+                      [SemanticAttributes.PARENT_QUEUE]: message.parentQueue,
+                      attempted_queues: attemptedQueues, // How many queues we tried before success
+                      attempted_envs: attemptedEnvs, // How many environments we tried before success
+                      message_timestamp: message.timestamp,
+                      message_age: this.#calculateMessageAge(message),
+                      message_priority: message.priority,
+                      message_enqueue_method: message.enqueueMethod,
+                      message_available_at: message.availableAt,
+                      ...flattenAttributes(message.data, "message.data"),
+                    };
+
+                    span.setAttributes(attributes);
+                    innerSpan.setAttributes(attributes);
+
+                    await this.options.subscriber?.messageDequeued(message);
+
+                    await this.options.visibilityTimeoutStrategy.startHeartbeat(
+                      messageData.messageId,
+                      this.visibilityTimeoutInMs
+                    );
+
+                    return message;
+                  }
+                } catch (error) {
+                  // Log error but continue trying other queues
+                  logger.warn(`[${this.name}] Failed to dequeue from queue ${messageQueue}`, {
+                    error,
+                  });
+                  return null;
+                }
+              },
+              {
+                kind: SpanKind.CONSUMER,
+                attributes: {
+                  [SEMATTRS_MESSAGING_OPERATION]: "dequeue",
+                  [SEMATTRS_MESSAGING_SYSTEM]: "marqs",
+                },
               }
+            );
 
-              const message = await this.readMessage(messageData.messageId);
-
-              if (message) {
-                span.setAttributes({
-                  [SEMATTRS_MESSAGE_ID]: message.messageId,
-                  [SemanticAttributes.QUEUE]: message.queue,
-                  [SemanticAttributes.MESSAGE_ID]: message.messageId,
-                  [SemanticAttributes.CONCURRENCY_KEY]: message.concurrencyKey,
-                  [SemanticAttributes.PARENT_QUEUE]: message.parentQueue,
-                  attempted_queues: attemptedQueues, // How many queues we tried before success
-                  attempted_envs: attemptedEnvs, // How many environments we tried before success
-                  message_timestamp: message.timestamp,
-                  message_age: this.#calculateMessageAge(message),
-                  message_priority: message.priority,
-                  message_enqueue_method: message.enqueueMethod,
-                  message_available_at: message.availableAt,
-                  ...flattenAttributes(message.data, "message.data"),
-                });
-
-                await this.options.subscriber?.messageDequeued(message);
-
-                await this.options.visibilityTimeoutStrategy.startHeartbeat(
-                  messageData.messageId,
-                  this.visibilityTimeoutInMs
-                );
-
-                return message;
-              }
-            } catch (error) {
-              // Log error but continue trying other queues
-              logger.warn(`[${this.name}] Failed to dequeue from queue ${messageQueue}`, { error });
-              continue;
+            if (result) {
+              return result;
             }
           }
         }