598
HTTPERRORNotable5xx Server Error (Unofficial)MEDIUM confidence

Network Read Timeout Error

Production Risk

Low — proxy-specific; indicates upstream is too slow or network is unstable.

What this means

598 Network Read Timeout Error is an informal status code used by some HTTP proxies to indicate that a network read timeout occurred while the proxy was waiting for data from the upstream server. It is not defined in any IETF standard.

Why it happens
  1. 1The upstream server started sending a response but stopped before completing it.
  2. 2A network interruption occurred mid-response transfer.
  3. 3The upstream server is under load and cannot send data fast enough to satisfy the proxy's read timeout.
  4. 4Large response body transfer timed out.
How to reproduce

A proxy receives the response headers from an upstream but the response body transfer stalls and times out.

trigger — this will error
trigger — this will error
GET /large-response HTTP/1.1
Host: example.com
# Proxy receives headers → body transfer stalls → read timeout

expected output

HTTP/1.1 598 Network Read Timeout Error

Fix

Increase proxy read timeout

WHEN Legitimate large responses are timing out.

Increase proxy read timeout
# nginx proxy read timeout
proxy_read_timeout 120s;

Why this works

Gives the upstream more time to complete sending the response body.

What not to do

Do not use 598 in new application or API designs

Use 504 Gateway Timeout — it is the IETF-standardised code for upstream timeout conditions.

Version notes
Informal

Not defined in any IETF RFC. Encountered in logs from some proxy software. Use 504 in new designs.

Sources
Official documentation ↗

Informal convention (no IETF RFC)

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