Improve keepalive-related options in Dart's nginx configuration.

dart/setup.py

@@ -3,8 +3,6 @@ import sys
 import setup_util
 import os
 
-#DART_SDK = os.environ('DART_SDK')
-
 def start(args):
   setup_util.replace_text('dart/postgresql.yaml', 'host: .*', 'host: ' + args.database_host)
   try:
@@ -34,19 +32,20 @@ def start(args):
     conf.append('    upstream dart_cluster {')
     for port in range(9001, 9001 + args.max_threads):
       conf.append('        server 127.0.0.1:' + str(port) + ';')
+    conf.append('        keepalive ' + str(args.max_concurrency / args.max_threads) + ';')
     conf.append('    }')
     conf.append('    server {')
     conf.append('        listen 8080;')
     conf.append('        location / {')
     conf.append('            proxy_pass http://dart_cluster;')
     conf.append('            proxy_http_version 1.1;')
+    conf.append('            proxy_set_header Connection "";')
     conf.append('        }')
     conf.append('    }')
     conf.append('}')
     #
     # write nginx configuration to disk
     #
-    #os.remove('dart/nginx.conf')
     with open('dart/nginx.conf', 'w') as f:
       f.write('\n'.join(conf))
     #