why will nginx's map directive eat all ram?

[Payne Chu]

here it is

nginx version: ngx_openresty/1.4.1.1
TLS SNI support enabled
configure arguments: --prefix=/usr/local/openresty/nginx
--with-cc-opt='-I/usr/local/Cellar/pcre/8.33/include
-I/usr/local/Cellar/luajit/2.02/luajit2.0/include'
--add-module=../ngx_devel_kit-0.2.18 --add-module=../echo-nginx-module-0.45
--add-module=../xss-nginx-module-0.03rc9 --add-module=../ngx_coolkit-0.2rc1
--add-module=../set-misc-nginx-module-0.22rc8
--add-module=../form-input-nginx-module-0.07
--add-module=../encrypted-session-nginx-module-0.03
--add-module=../srcache-nginx-module-0.21 --add-module=../ngx_lua-0.8.5
--add-module=../headers-more-nginx-module-0.21
--add-module=../array-var-nginx-module-0.03rc1
--add-module=../memc-nginx-module-0.13rc3
--add-module=../redis2-nginx-module-0.10
--add-module=../redis-nginx-module-0.3.6
--add-module=../auth-request-nginx-module-0.2
--add-module=../rds-json-nginx-module-0.12rc10
--add-module=../rds-csv-nginx-module-0.05rc2
--with-ld-opt='-Wl,-rpath,/usr/local/openresty/luajit/lib
-L/usr/local/Cellar/pcre/8.33/lib
-L/usr/local/Cellar/luajit/2.02/luajit2.0/lib'
--http-client-body-temp-path=/var/tmp/nginx/client_body
--http-proxy-temp-path=/var/tmp/nginx/proxy
--http-fastcgi-temp-path=/var/tmp/nginx/fastcgi
--http-uwsgi-temp-path=/var/tmp/nginx/uwsgi
--http-scgi-temp-path=/var/tmp/nginx/scgi --with-http_ssl_module

Actually Im using OpenResty. But since OpenResty said it's just standard
nginx. and in config I not even active any lua directive yet. so I thought
this should the nginx probelm. But when I install nginx-1.4.1 through
`Homebrew`. I cannot find same issue in the brew version. Maybe just one of
OpenResty used module trigger this. below is the config trigger this issue.
And let me know if I need to forward this issue to OpenResty. Thanks :)

user paynechu staff;
worker_processes 1;

events {
  worker_connections 1024;
}

http {

  map $pid $public_root { default public; }

  server {
    listen 443;
    index index.html;
    ssl on;
    ssl_certificate ssl/sandbox.crt;
    ssl_certificate_key ssl/sandbox.key;
    ssl_session_timeout 5m;
    ssl_protocols SSLv2 SSLv3 TLSv1;
    ssl_ciphers HIGH:!aNULL:!MD5;
    ssl_prefer_server_ciphers on;
    root $public_root;
  }
}

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,241478,241499#msg-241499