TCPHA-0.3

What is it?
-----------
TCPHA implements an architecture for 
scalable content-aware request distribution in 
cluster-based servers.It implements TCP Handoff
inside kernel for the LINUX operating system.
TCPHA can be used to build a high-performance and highly available 
server based on a cluster of Linux servers.

What's the architecture of TCPHA?
--------------------------------
TCPHA is composed of tcpha_fe (dispatcher), tcpha_be (real server). 
The dispatcher(FE) does the content-aware request distribution to 
real servers(BEs).Real servers(BEs) serve requests and send responses 
to clients directly.

The softwares needed by TCPHA
-------------------------------
Linux with Kernel-2.4.18 and later,Gcc

COPYRIGHT
---------
Copyright (c) 2004 Li Wang. It is released under GNU GPL
(General Public License). Please see the file called COPYING.

Fastest setup
---------------
Let's assume your cluster has the following configuration:
Workstation with address:192.168.1.23 runs as dispatcher(FE:front end),
Workstations with address:192.168.1.33 and 192.168.1.38 run as real server(BE:back end).
Thay all share address:192.168.1.36,which is saw by client.
First,you should execute the following commands in shell:
Shell>tar -zxvf tcpha-0.3.tar.gz
Shell>cd tcpha
Then you should choose to install which component.In this case,surely,you should install 
tcpha_fe on 192.168.1.23,install tcpha_be on 192.168.1.33 and 192.168.1.38.
Install tcpha_fe
1.	Shell>fe/make
2.	Modify the file:fe/tcphafe.conf according to your cluster configuration.
	Generally speeking,you need only change the following:
	'raddr = x.x.x.x' to the FE real address,So here you should change the line to 'raddr = 192.168.1.23'
	'vaddr = x.x.x.x' to the cluster shared virtual address,here 'vaddr = 192.168.1.36'
	'server = x.x.x.x port' to the BE address and port,here 'server = 192.168.1.33 666' and 'server = 192.168.1.38 666'
	'rule = x.x.x.x pattern' stands for:if a request matching 'pattern' uses BE:x.x.x.x to handle it,the pattern
	should be regular expressions.such as 'rule = 192.168.1.38 jpg$' and 'rule = 192.168.1.33 .*'
3.     Shell>mkdir /etc/tcpha;cp fe/tcphafe.conf /etc/tcpha/
Install tcpha_be
1.	Shell>be/make
2.	Modify the file:be/tcphabe.conf according to your cluster configuration.
	Generally speeking,you need only change the following:
	'raddr = x.x.x.x' to the BE real address,So here you should change the line to 'raddr = 192.168.1.33'
	'uaddr = x.x.x.x' to a address the cluster NOT used,for example: if 192.168.1.39 is not used in your cluster,
	you can change the line to 'uaddr = 192.168.1.39'
	'vaddr = x.x.x.x' to the cluster shared virtual address,here 'vaddr = 192.168.1.36'
	'fe = x.x.x.x port' to the FE address and port,here 'fe = 172.18.20.23 666'
	'server = x.x.x.x port' to the BE address and port,here 'server = 192.168.1.33 666' and 'server = 192.168.1.38 666'
	'rule = x.x.x.x pattern' stands for:if a request matching 'pattern' uses BE:x.x.x.x to handle it,the pattern
	should be regular expressions.such as 'rule = 192.168.1.38 jpg$' and 'rule = 192.168.1.33 .*'
3.	Shell>mkdir /etc/tcpha;cp be/tcphabe.conf /etc/tcpha/

How to use
--------------
Start
You should start the components by the following order(assume you are in shell path 'tcpha/'):
Start BE:
1.	Shell>insmod be/ktcphabe.o
2.    Shell>ifconfig tunl0 192.168.1.36 up
3.    Shell>httpd
Start FE:
1.	Shell>ifconfig tunl0 192.168.1.36 up
1.	Shell>insmod fe/ktcphafe.o
Ok,as you see,setup and run are very simple, Enjoy to explore it!
Stop
You should stop the components by the following order(assume you are in shell path 'tcpha/'):
Stop FE:
1.	Shell>ifconfig tunl0 down
2.	Shell>echo 1 >> /proc/sys/net/ktcphafe/unload
2.	Shell>rmmod ktcphafe
Stop BE:
1.	Shell>ifconfig tunl0 down
2.	Shell>echo 1 >> /proc/sys/net/ktcphabe/unload
3.	Shell>rmmod ktcphabe

Costomize setup
---------------
You can look at the files:fe/tcphafe.conf.detail and be/tcphabe.conf.detail for reference.

Notes
------
1.	When you stop BE,the step 1 must be done before step 2 and 3
2.	The rules must contain all the cases,so you'd better add rule: 'rule = x.x.x.x .*' in the config file
3.	The configuration of 'server=...' and 'rule=...' must be the same in FE and BEs

Feedback
--------
Welcome your comments, bug reports, bug fixes, and ideas

Thanks,

Li Wang
dragonfly@linux-vs.org