Fixing cpu hog with all upstream servers marked "down". The following configuration causes nginx to hog cpu due to infinite loop in ngx_http_upstream_get_peer(): upstream backend { server 127.0.0.1:8080 down; server 127.0.0.1:8080 down; } server { ... location / { proxy_pass http://backend; } } Make sure we don't loop infinitely in ngx_http_upstream_get_peer() but stop after resetting peer weights once. Return 0 if we are stuck. This is guaranteed to work as peer 0 always exists, and eventually ngx_http_upstream_get_round_robin_peer() will do the right thing falling back to backup servers or returning NGX_BUSY.

/*
 * Copyright (C) Igor Sysoev
 */


#include <ngx_config.h>
#include <ngx_core.h>


int ngx_file_type(char *file, ngx_file_info_t *sb)
{
    sb->dwFileAttributes = GetFileAttributes(file);

    if (sb->dwFileAttributes == INVALID_FILE_ATTRIBUTES) {
        return -1;
    }

    return 0;
}

/*
int ngx_stat(char *file, ngx_stat_t *sb)
{
    *sb = GetFileAttributes(file);

    if (*sb == INVALID_FILE_ATTRIBUTES) {
        return -1;
    }

    return 0;
}
*/