What does the ngx_http_degradation_module do

Question

Nginx

What does the ngx_http_degradation_module do?

Answer 1

In general, it allows, when a certain amount of memory occupied by the process is exceeded, to return a 204th response or 444 (silently close the connection). And it works mostly only on fryaha up to version 7, because on others malloc can use mmap in certain cases.

Answer 2

nginx.org/pipermail/nginx-ru/2009-November/029723.html

The module allows you to return 204 or 444 for some locations:

http {
    degradation sbrk=500m;

    server {

       location /some {
           degrade 204;
       }

At the moment it can only be used in cases where sbrk(0)
shows the actual amount of memory allocated by the process. That is, the module
works on FreeBSD up to version 7.0. Starting from 7.0, it works provided
that MALLOC_OPTIONS=Dm. Will not work under Linux.