GCP Cloud Functions Triggering Multiple Instances for Single Pub/Sub Message - advanced patterns
I need some guidance on I'm attempting to set up I'm working with an scenario where my GCP Cloud Function, which is supposed to process messages from a Pub/Sub topic, is triggering multiple instances for a single message. I have a topic with a subscription configured to push messages to the Cloud Function. However, I noticed that for every message published, the function is invoked up to three times, which is not the expected behavior. Here’s a brief overview of my setup: I have a Pub/Sub topic named `my-topic`, and a subscription `my-subscription` linked to it. The subscription is set up for push delivery to my Cloud Function's endpoint. I’m using the Node.js runtime (version 14) for my Cloud Function, and the code looks like this: ```javascript exports.processMessage = (req, res) => { const message = req.body.message.data ? Buffer.from(req.body.message.data, 'base64').toString() : null; console.log(`Processing message: ${message}`); res.status(200).send('Message processed'); }; ``` I’ve validated that messages are not being published multiple times, as I monitor the publishing process and can confirm each message is sent only once. Additionally, I have set up dead-letter topics, but they remain empty, indicating the function isn't failing or throwing errors. To troubleshoot, I've: - Checked the Cloud Function logs for any clues about multiple invocations, but nothing stands out. - Reviewed the configuration settings for the subscription, ensuring that acknowledgment deadlines and retry policies are set correctly. - Ensured that no other services are trying to push the same message to the function, which I confirmed by checking IAM permissions and access logs. I’m at a loss here. Could it be related to the way the Pub/Sub service handles message delivery, or is there something in my configuration that could cause this behavior? Any insights would be greatly appreciated. I'm on Linux using the latest version of Javascript. What are your experiences with this? What am I doing wrong?