[PHP] Re: What Is Scalability?
Hi, I think that software scalability is the measure on how an application could accomodate a large number of simultaneous users without requiring internal architecture refactoring. It's not about speed, it's not about technology, it's about architecture. I also think that maintenance and development time are not attributes of scalability - but of the architecture. We can even make a simple comparision between scalability and the law of Demeter (low coupling) - the scalability of an architecture is reversely proportional with the number of message pipelines between it's layers. That means that a simple architecture (like PHP/Perl) will accomodate much simpler a large number of users because it's messages can be very simply mirrored horizontally - adding CPU power and RAM. An application built on complex architecture (Java with RMI, direct memory access between threads, etc) will require a very complex architecture refactoring to support horizontal scaling. Anyway - I am also supporting MVC software development in PHP from the same reason - low coupling between layers that will lead to ease of development and maintenance. My 2c Alexandru -- Alexandru COSTIN Chief Operating Officer http://www.interakt.ro/ +4021 312 5312 Chris Shiflett [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] PHP has been both heralded and criticized on a number of topics. This is to be expected, considering the rate of growth of PHP's popularity. It has given people something to talk about. One topic that seems to come up a lot is scalability. ONJava.com has an interesting article entitled The PHP Scalability Myth: http://www.onjava.com/pub/a/onjava/2003/10/15/php_scalability.html Of particular interest to me is the variety of definitions for scalability that I have noticed, both in this article and elsewhere. I wrote a brief description of what scalability is to me in my blog (http://shiflett.org/). How do you define scalability? What factors do you consider when you declare whether a particular technology is scalable? Do you think PHP is scalable? Does Yahoo? Chris = My Blog http://shiflett.org/ HTTP Developer's Handbook http://httphandbook.org/ RAMP Training Courses http://www.nyphp.org/ramp -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
[PHP] Re: What Is Scalability?
Chris Shiflett [EMAIL PROTECTED] wrote in message news:[EMAIL PROTECTED] How do you define scalability? What factors do you consider when you declare whether a particular technology is scalable? Do you think PHP is scalable? Does Yahoo? Well, from I think that your approach is interesting, especially with 3 graphs with kinds of scalability. Anyway, I am not sure one can draw such graphs for just technologies like java or php. Maybe for some specific app it can be done. Even then one should be quite causios not to compare apples and oranges, and also to measure scalability in really important matters. Also there is one trivial kind of scalability that is often found: when some solution does not scale at all. You can put as much servers, processors, ram, you are still stuck. Notorious and overused example is delivering the baby problem. You can engage as many women as you wish, it still takes a 9 months. Since people have often been caught in the situation with technologies where no adding of resources can make difference, they are content that there is at least some possibility to scale, so that they say this technology can scale to differentiate it from complete dead ends. rush p.s. I really enjoyed your book :) -- http://www.templatetamer.com/ -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
