Tune worker_connections based on dyno size.

These numbers arrived at by wildly unscientific methods involving apachebench.

scripts/boot

@@ -6,6 +6,15 @@ HERE=$(dirname "$0")
 
 # Reify the environment into an nginx config file, since nginx doesn't support
 # environment variables particularly well
+case $(ulimit -u) in
+512)   # 2X Dyno
+  export WORKER_CONNECTIONS=2048
+  ;;
+*)     # 1X, PX, IX, Hobby, Free Dynos
+  export WORKER_CONNECTIONS=2048
+  ;;
+esac
+
 "${HERE}/config/make-config"
 
 # make a shared pipe; we'll write the name of the process that exits to it once

scripts/config/make-config

@@ -14,6 +14,7 @@ class NginxConfig
   def initialize(json_file)
     json = {}
     json = JSON.parse(File.read(json_file)) if File.exist?(json_file)
+    json["worker_connections"] ||= ENV["WORKER_CONNECTIONS"] || 512
     json["port"] ||= ENV["PORT"] || 5000
     json["root"] ||= "public_html/"
     json["proxies"] ||= {}

scripts/config/templates/nginx.conf.erb

 daemon off;
-worker_processes 4;
+worker_processes auto;
 
 events {
   use epoll;
   accept_mutex on;
-  worker_connections 1024;
+  worker_connections <%= worker_connections %>;
 }
 
 http {