How do I configure nginx to return 429 http code when rate limiting?

Question

How do I configure nginx to return http status code 429 (Too Many Requests) instead of the default 503 (Service Unavailable) when throttling/rate limiting?

FYI, I'm using nginx as a reverse proxy with the HttpLimitReqModule. The draft spec for 429 status code is RFC6585.

This (closed) question on stackexchanged shows that it is possible to use the error_page directive. However, I don't want to return a 429 if there really is a server problem (not the customer hitting us too much) and the server should be returning 503 Service Unavailable.

Any suggestions?

score 38 · Accepted Answer · answered Apr 18 '13 at 13:40

Good news, with Version 1.3.15 http://mailman.nginx.org/pipermail/nginx/2013-March/038306.html

we have the "limit_req_status" and "limit_conn_status" directives. I just tested them on Gentoo Linux (note that you need to have the modules limit_req and limit_con compiled in).

With these settings I think you can achieve what you've asked for:

limit_req_status 429;
limit_conn_status 429;

I have verified this with a quick:

ab2 -n 100000 -c 55 "http://127.0.0.1/api/v1

On which most request failed after activating the directive due to the high request rate and the configured limit in nginx:

limit_req zone=api burst=15 nodelay;

score 1 · Answer 2 · answered Mar 06 '13 at 14:58

Based on VBart's response and other comments, it is clear that the best option is to map 503 errors to 429s.

error_page 503 = 429 /too-many-requests.html

Since nginx (1.3.x) only uses 503 status codes for limit_req and limit_conn, this should be a fine approach.

score 0 · Answer 3 · answered Mar 01 '13 at 15:01

0

Nginx itself never returns 503 in cases other than limit_req and limit_conn.

answered Mar 01 '13 at 15:01

VBart

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How do I configure nginx to return 429 http code when rate limiting?

3 Answers3