🐞 Fix startup freeze in EmailQueueService during Redis connection

[Copilot]

The application was freezing during startup at "Creating marketing queue for region" when running in Docker environments, particularly after configuring SMTP services. This occurred because the BullMQ Worker constructor would hang indefinitely when Redis connections experienced delays or failures.

Root Cause

The issue was in the EmailQueueService.initializeQueue() method where:

• No timeout protection for Redis connections or BullMQ queue/worker creation
• Synchronous initialization could hang indefinitely on connection issues
• Missing error handlers for Redis connection failures
• Docker networking delays causing connection hangs without recovery

Solution

1. Redis Connection Resilience

• Added 10-second connection timeout with connectTimeout: 10000
• Implemented comprehensive error event handlers for connection monitoring
• Added connection status logging for better debugging
• Used lazyConnect: true for improved connection management

2. Timeout Protection for Queue Initialization

• Made initializeQueue() asynchronous with 15-second timeout wrapper
• Added createQueueAndWorkerWithTimeout() method to prevent indefinite hangs
• Implemented proper error handling and logging throughout the initialization process

3. Enhanced Error Handling

• Added error event handlers for both Queue and Worker instances
• Improved logging with detailed context (region, queue name, quotas)
• Added graceful error handling in instrumentation.ts to prevent app crashes

4. Production Readiness

• Application now fails fast with clear error messages instead of hanging
• Maintains backward compatibility with existing configurations
• Works correctly in Docker environments with service dependency timing

Testing

The fix ensures the application will either:

1. ✅ Start successfully when Redis is available
2. ⚡ Fail fast with clear error messages when Redis is unavailable (15s timeout)
3. 🚫 Never hang indefinitely during startup

This is particularly important for Docker deployments where container networking can introduce connection delays.

Fixes #231.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• binaries.prisma.sh
  • Triggering command: node scripts/postinstall.js (dns block)
  • Triggering command: node /home/REDACTED/work/useSend/useSend/node_modules/.pnpm/@prisma+[email protected][email protected][email protected]/node_modules/@prisma/client/node_modules/.bin/../../../../../../[email protected][email protected]/node_modules/prisma/build/index.js -v (dns block)
• googlechromelabs.github.io
  • Triggering command: node install.mjs (dns block)
• https://storage.googleapis.com/chrome-for-testing-public/127.0.6533.88/linux64/chrome-linux64.zip
  • Triggering command: node install.mjs (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

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Project	Deployment	Preview	Comments	Updated (UTC)
unsend-marketing	Ready	Preview	Comment	Sep 15, 2025 8:59pm

[cloudflare-workers-and-pages]

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