Hi all,

We use an apache httpd as a forward proxy load balancer, which
forwards requests to one of the two internal Tomcat application
servers. There are some issues with the performance of mod_proxy. We
have enabled logging to time to serve request for both the httpd and
Tomcat servers.

Many a times (in around 10-15% of all requests), time to respond for
the httpd is 5-10 seconds while the Tomcat server was able to serve
the request in less than a second. This means that the httpd is adding
a delay of 5-10 seconds in just fetching the content from Tomcat and
sending it to the client. What could be the reason for this delay.

Some details about our setup:
- We are using a compiled from source apache 2.2 on RHEL 4.
- all our servers are on high-speed internal LAN which is not clogged.
- httpd server is run on a 4-processor AMD machine with 8 GB RAM. CPU
usage never exceeds 100% (of 400% available). Swap usages are zero.
This means, there is no lack of resources.
- The traffic is around 70-80 requests a minute, which consists of
many small static image and js files and some dynamic files from
Tomcat.
- Rewrite rules are used for redirecting the traffic:
ProxyPassReverseCookiePath /appname  /
RewriteMap SERVERS rnd:/etc/httpd/conf/balancer.conf
RewriteEngine On
RewriteRule ^/static/(.*)   /path/to/static/$1 [L]
RewriteCond "%{HTTP_COOKIE}"        "(^|;\s*)JSESSIONID=\w*\.(\w+)($|;)"
RewriteRule "(.*)"      "http://${SERVERS:%2}%{REQUEST_URI}";  [P,L]
RewriteRule "^.*;JSESSIONID=\w*\.(\w+)($|;)"
"http://${SERVERS:$1}%{REQUEST_URI}";  [P,L]
RewriteRule "(.*)"  "http://${SERVERS:ALL}%{REQUEST_URI}"; [P,L]

Any help will be greatly appreciated.

thanks
Nilesh Bansal.
http://queens.db.toronto.edu/~nilesh/

---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: [EMAIL PROTECTED]
  "   from the digest: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to