Hi Railway Support,

We're experiencing MongoDB connection failures between services in our staging environment.

Problem:

• Service apostrophe-cms cannot connect to MongoDB service MongoDB-wgiF

• Error: MongoServerSelectionError: Server selection timed out after 30000 ms

• Target: mongodb-wgif.railway.internal:27017

• App crashes and restarts in a loop

Service Details:

• MongoDB Service: MongoDB-wgiF - redeployed 2 hours ago

• App Service: apostrophe-cms - deployed 2 hours ago via Railway CLI

• Environment: Staging

• Project: [Your project name]

Important Finding:

MongoDB logs show successful connections and authentication:

• Connection accepted at 09:22:22 and 09:35:38

• Successfully authenticated

• Received first command on ingress connection

This indicates:

• MongoDB is accessible and accepting connections

• Private network DNS resolution is working

• Authentication is successful

However, the app still times out when trying to connect, suggesting:

1. App may be connecting before MongoDB is ready (timing issue)

1. Connection string format mismatch

1. App using a different hostname/endpoint than what's working

Troubleshooting Attempted:

1. Restarted MongoDB service - no change

1. Redeployed MongoDB service - no change

1. Verified services show as "online" in dashboard

1. Confirmed APOS_MONGODB_URI environment variable is set

1. MongoDB logs show successful connections from other sources

Questions:

1. Could there be a startup timing issue where the app connects before MongoDB is ready?

1. Should we add a connection retry/delay mechanism?

1. Is the connection string format correct for Railway's private network?

1. Are there any connection pool or timeout settings we should adjust?

Request:

Please investigate why the app cannot connect despite MongoDB accepting other connections successfully. The private network appears functional, but the app service cannot establish a connection.

Thanks!