KTCPVS HHTTP

Introduction

The hhttp scheduler in KTCPVS is to assign jobs to servers according to the specified content-based scheduling rules, in which regular expression matches are hashed and the virtual server is selected based on the resulting hash value.

Using the KTCPVS HHTTP scheduler

In the example, ktcpvs is used to forward requests to different users web pages /users/<username>/.* to different web servers, in which server is selected based on the hash value of username. The tcpvsadm commands are as follows:

 tcpvsadm -A -i web -s hhttp
 tcpvsadm -a -i web -r 192.168.0.10:80
 tcpvsadm -a -i web -r 192.168.0.11:80
 tcpvsadm -a -i web -r 192.168.0.12:80
 
 tcpvsadm --add-rule -i web --pattern="/users/([^/]+)/.*" -m 1 -r 192.168.0.10:80
 tcpvsadm --add-rule -i web --pattern="/users/([^/]+)/.*" -m 1 -r 192.168.0.11:80
 tcpvsadm --add-rule -i web --pattern="/users/([^/]+)/.*" -m 1 -r 192.168.0.12:80

The configuration file is as follows:

Virtual web {
   listen = 0.0.0.0:webcache
   scheduler = hhttp
   startservers = 8
   maxclients = 256
   minspareservers = 6
   maxspareservers = 18
   server = 192.168.0.12:www 1
   server = 192.168.0.11:www 1
   server = 192.168.0.10:www 1
   rule = pattern "/users/([^/]+)/.*" match 1 use server 192.168.0.12:www
   rule = pattern "/users/([^/]+)/.*" match 1 use server 192.168.0.11:www
   rule = pattern "/users/([^/]+)/.*" match 1 use server 192.168.0.10:www
}