[SSI-users] clustering why-to

[Alexandre C. <aco...@ma...>]

Hello,

I want to setup a clustering environement. I read many how-to's out 
there, but not many why-to's actually.

So my main question is: "would I need a cluster system for what I'd like 
to do ?"


1/ Here is how my application works today:
I have 1 web server and 1 database server. I have multiple remote 
clients (PCs) that sends data every night the database server. There is 
a lot of information and the database is getting bigger and bigger 
pretty quickly.

Then a client (human) can connect to the web server and have a graphical 
interface to manipulate some statistics from the data in the database.

2/ Here is my problem:
When a human client connects to the web server to make some statistics, 
1 request takes a long time to process because a lot of data is parsed 
and computed. And it's taking too much time.

Today, my application works as a "test", but it's gonna get bigger and 
bigger with more and more client PCs that will send data to the database.

So I'm worried that my 1 database just won't handle it.

3/ Here is my idea:
I want to keep 1 web server because I don't have much human clients that 
want to play with the statistics (low trafic). But because the database 
is getting bigger and bigger, I want to be able to add some extra 
storage over another database server.

So I got my self 3 servers for the database (dual Xeon + RAID5). I'd 
like to have all servers in a cluster seen as 1 logical database. That 
way, data would be shared over all 3 servers transparently, the web 
server would talk only to 1 ip address like if it was 1 single database.

4/ Here are the problems that could happend:
- If I run out of disk space, I'll add a 4th server inside the cluster 
and it will automaticly share data over the new server.

- If a server fails, I want to make sure I have data intergrety (if one 
fails, it can still run with the left servers). When the failed server 
is replaced, it will reconstruct it's data and be available again.


So here are my questions:
- Is my project feasable with my current hardware configuration ?
- Is clustering what I'm looking for ?
- What is clustering after all if what I'm talking about it not clustering ?

I'm in a little hurry for my porject... please help !!

Best regards,
-- 
Alexandre CONRAD - TLV
Research & Development
tel : +33 1 30 80 55 05
fax : +33 1 30 80 55 06
6, rue de la plaine
78860 - SAINT NOM LA BRETECHE
FRANCE