Repair Queue Visibility Timeout Bugs

I have analyzed the worker logic. The duplicate execution occurs because the SQS visibility timeout expires before the image processing finishes, causing the message to reappear in the queue while the first worker is still active.

SQS Visibility Heartbeat Implementation

const { SQSClient, ChangeMessageVisibilityCommand } = require("@aws-sdk/client-sqs");

async function processImageWithHeartbeat(message, context) {
  const sqs = new SQSClient({});
  const heartbeatInterval = 20000; // 20s (inside 30s window)
  
  const heartbeat = setInterval(async () => {
    try {
      await sqs.send(new ChangeMessageVisibilityCommand({
        QueueUrl: process.env.QUEUE_URL,
        ReceiptHandle: message.ReceiptHandle,
        VisibilityTimeout: 30
      }));
      console.log("Heartbeat: Visibility timeout extended.");
    } catch (err) {
      console.error("Heartbeat failed", err);
    }
  }, heartbeatInterval);

  try {
    // Existing image processing logic
    await resizeImage(message.Body);
  } finally {
    clearInterval(heartbeat);
  }
}

Next steps

1. Update the VisibilityTimeout in your ChangeMessageVisibilityCommand to match your queue's default.
2. Ensure the IAM role for the worker has the sqs:ChangeMessageVisibility permission.
3. Deploy a test job with a 60-second sleep to verify the heartbeat extends the lease successfully.