NYCPHP Meetup

[Tim Gales]

Well it definitely has to do with the 'size of the problem'
and maybe 'bang for the buck' also.

It's more than just the number of (concurrent) users -- it's
also the amount of data and the work performed on the data.

A schema for a database might be okay for queries against
8-10 thousand items but have response problems at say 80-100
thousand items.

Ultimately you have to have some measure of throughput and I
guess 'transactions per second' is about the best.

Then you need a 'rate of change' measurement like to go from
200 tps to 500 tps using technology 'A' costs an additional
3 cents per transaction. Technology 'B' will cost you 4 1/2
cents to do the same. But when you 'scale up', the move from
500 to 1000 tps technology 'A' has an incremental cost of 2
1/2 cents whereas technology 'B' has an incremental cost of
only 1 1/2 cents.  So if you make a chart of tps / cost per
transaction at the start technology 'A' is less expensive,
but as time and the number of transactions move on and up,
technology 'B' is cheaper because it 'scales'. 

Anyway the idea that PHP doesn't scale is ridiculous.

"www.php.net serves almost 2M hits (mostly PHP-generated
pages) per day from a single PII-350..." 
  at  
http://www.phpbuilder.com/mail/php3-list/200003/4480.php

T. Gales & Associates
Helping People Connect with Technology
http://www.tgaconnect.com

-----Original Message-----
From: talk-bounces at lists.nyphp.org
[mailto:talk-bounces at lists.nyphp.org] On Behalf Of Chris
Shiflett
Sent: Monday, October 20, 2003 12:00 PM
To: NYPHP Talk
Subject: What Is Scalability? Was: [nycphp-talk] PHP vs. Java
scalability ...

...
So, we may as well discuss it here also. How do you define
scalability? What
does it mean?

Chris

..