HTTP request in ngx.timer.at context is blocking all the incoming requests

annaok · 2015-10-15T22:28:44+00:00

Hello! On Thu, Oct 15, 2015 at 6:23 PM, 杨阳 wrote: > Hi, agentzh > BTW, it's not a good practice to address my nick while sending mails...

HTTP request in ngx.timer.at context is blocking all the incoming requests

annaok

Hi,

We've implemented the following logic in our openresty servers:

init_worker_by_lua launches recurring timer (nginx.timer.at) that each x minutes performs HTTP request (OAuth lua module that uses socket.http module). The purpose is to maintain in-memory cache available in each worker.

The problem is that when the HTTP request target is slow or unavailable, worker processes become not responsive because of the blocking IO and don't handle the incoming client requests.

The question is if there is a way to perform the cache update in a separate thread such that it won't affect the worker request handling.

Thanks,

Anuta.

aapo.talvensaari

On Thursday, 15 October 2015 16:28:46 UTC+2, Anuta  wrote:
> The problem is that when the HTTP request target is slow or unavailable, worker processes become not responsive because of the blocking IO and don't handle the incoming client requests

You have to non-blocking ngx.tcp or say lya-resty-http. It is easy to replace your library to use those.

annaok

Thank you,

I also found an older thread on the same issue: https://groups.google.com/forum/#!topic/openresty-en/6OwhJioFVoo

On Thursday, October 15, 2015 at 6:22:14 PM UTC+3, Aapo Talvensaari wrote:

On Thursday, 15 October 2015 16:28:46 UTC+2, Anuta wrote:
> The problem is that when the HTTP request target is slow or unavailable, worker processes become not responsive because of the blocking IO and don't handle the incoming client requests
You have to non-blocking ngx.tcp or say lya-resty-http. It is easy to replace your library to use those.