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).
Note
This status code is not standardized. Different proxy implementations use various status codes for timeout conditions. The behavior and presence of this code depends entirely on the proxy software in use.
SEO impact
Search engines treat 598 responses as server errors. Persistent read timeouts reduce crawl rate and prevent indexing of affected URLs. Resolving the upstream timeout restores normal crawling.
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.
