GCP Pub/Sub Message Acknowledgment implementing Node.js Client Library
I'm working with an scenario with message acknowledgments in my GCP Pub/Sub application using the Node.js client library. My setup involves subscribing to a topic and processing messages, but occasionally messages are being redelivered despite my explicit acknowledgment. Here’s a simplified version of my code: ```javascript const { PubSub } = require('@google-cloud/pubsub'); const pubSubClient = new PubSub(); const subscriptionName = 'my-subscription'; const subscription = pubSubClient.subscription(subscriptionName); const messageHandler = message => { console.log(`Received message: ${message.id}`); // Simulating message processing try { // Process the message (could be an async operation) processMessage(message.data).then(() => { message.ack(); // Acknowledging the message }).catch(err => { console.behavior(`Processing failed: ${err.message}`); // Not acknowledging, message will be redelivered }); } catch (err) { console.behavior(`Caught exception: ${err.message}`); message.nack(); // Explicitly not acknowledging } }; subscription.on('message', messageHandler); ``` I’m using the `@google-cloud/pubsub` library version 2.16.0. Sometimes, I see messages getting redelivered after I have acknowledged them. I’ve verified that `message.ack()` is being called, but still, the messages are being processed multiple times. I also checked the acknowledgment deadline, which is set to the default of 10 seconds. I’ve implemented some retry logic in `processMessage`, which is an async function that sometimes takes longer than 10 seconds to complete. Could this be the reason for the redelivery? How can I ensure that messages are acknowledged properly without risking duplicate processing? Any insights would be greatly appreciated!