Nginx/Apache/Load Balancer Gateway Timeout

The server, acting as a gateway or proxy, did not receive a timely response from an upstream server.

Common Causes

Upstream server (application, database, API) is overloaded or has crashed.
Network latency or connectivity issues between the proxy and upstream server.
Proxy server timeout settings (e.g., proxy_read_timeout) are too low for the upstream response.

How to Fix

1 Increase Proxy Timeout Settings (Nginx)

Increase the timeout values for reading from the upstream server in your Nginx configuration.

BASH

 $ location / {
    proxy_pass http://upstream_backend;
    proxy_read_timeout 300s; # Increase from default 60s
    proxy_connect_timeout 75s;
}

2 Check Upstream Server Health

Verify the upstream application or service is running and responsive. Check logs for errors.

BASH

 $ # Check if the service is running
systemctl status your-application

# Check application logs
journalctl -u your-application -f

# Test connectivity to the upstream port
telnet upstream-server-ip 8080

3 Scale Upstream Resources

If the upstream server is overloaded, scale the application horizontally (add more instances) or vertically (increase CPU/RAM).

BASH

 $ # Example: Scale a Kubernetes deployment
kubectl scale deployment/my-app --replicas=5

# Check resource usage on the upstream server
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