598 Network Read Timeout Error

The HTTP 598 Network Read Timeout Error status code is an unofficial HTTP status code used by some proxies to signal a network read timeout behind the proxy.

Usage

The 598 Network Read Timeout Error status code is an informal convention indicating the proxy established a connection to the upstream server but the read operation timed out before a complete response arrived. The request remains unfulfilled.

This status code is not defined in any RFC or formal specification. Some proxy implementations and custom middleware use the code to distinguish read timeouts from connection timeouts (signaled by 599 Network Connect Timeout Error).

Example

A proxy forwards a request to an upstream API server. The upstream accepts the connection but does not send a response within the proxy's read timeout window.

Request

GET /api/search HTTP/1.1
Host: www.example.re
Accept: application/json

Response

HTTP/1.1 598 Network Read Timeout Error
Date: Sun, 02 Mar 2026 11:15:00 GMT
Content-Type: text/plain

Network read timeout while waiting for
upstream response

How to fix

The fix depends on the proxy software generating the 598 response. The connection to the upstream succeeded, but the upstream did not send a complete response in time.

Increase the proxy read timeout. In Nginx, adjust proxy_read_timeout (default 60 seconds) to match the upstream's expected response time:

location /api/ {
    proxy_pass http://upstream;
    proxy_read_timeout 120s;
}

For FastCGI upstreams in Nginx, use fastcgi_read_timeout instead. In HAProxy, the equivalent setting is timeout server.

Optimize the upstream endpoint. Profile slow database queries, blocking I/O, or resource-intensive processing on the upstream server. A faster upstream response eliminates the timeout entirely.

Check network conditions. High latency or packet loss between the proxy and upstream delays response delivery. Run ping and traceroute between the two hosts to identify congestion or routing problems. Placing the proxy and upstream in the same datacenter or availability zone reduces network-induced delays.

Monitor upstream health. Configure the proxy's health check to detect unresponsive upstreams and route traffic to healthy instances. In Nginx, use the max_fails and fail_timeout directives on the upstream block. In HAProxy, configure option httpchk with an appropriate check interval.

Takeaway

The 598 Network Read Timeout Error status code is an unofficial proxy error indicating the upstream connection was established but the response was not received within the read timeout period.

See also

• 599 Network Connect Timeout Error
• 504 Gateway Timeout
• 408 Request Timeout
• HTTP status codes