Error "WARN: Error in stream connection (will retry): EOF"

Affected: Relay Proxy

Symptoms

When using the Relay Proxy, you may encounter:

• WARN: Error in stream connection (will retry): EOF

Cause

This error could occur if the Relay Proxy is unable to successfully make a long-lived streaming connection with LaunchDarkly servers.

If you are in AWS, then application load balancers (ALBs), by default, disconnect idle connections after 60 seconds of inactivity. The Relay Proxy sends one byte of data every 3 minutes to keep the connection alive. Since the Relay Proxy's heartbeat is 3 minutes, and ALBs' timeout is only 1 minute, ALB will keep closing the connection before the Relay Proxy has a chance to send its heartbeat.

Solution

To resolve this error, our domains and/or public IPs need to be allow-listed. This could happen anywhere in the network, such as a VPN, firewall, or load balancer.

In AWS,

1. Follow the instructions listed in the ALB documentation.
2. Set the "Idle timeout" to a value >180 seconds (3 minutes).

• Network troubleshooting checklist