Asthana, Rahul wrote:
By the way, have any of you done any performance metrics on an ajax based
implementation vs a non ajax based one?
Early on we did a proof-of-concept that did exactly this... what we
found was that the AJAX version was universally perceived as being
faster, even when a few cases actually weren't (i.e., client-side
processing took longer than the equivalent server-side version).
The conclusions we drew were:
1. You have to strive to minimize the amount of Javascript executing as
a result of each AJAX call. There is a line that when crossed means the
server can actually render the whole page fresh and the browser can
display it faster than AJAX+Javascript updates.
2. There is a balance you need to strike between the number of AJAX
calls and size of each AJAX response... there is again a line that when
crossed means that X number of small AJAX requests takes more time than
one non-AJAX "transaction".
3. There is definitely tuning that needs to be done in terms of moving
static resources off to the web server, making sure your AJAX responses
are tight, things like that. The very biggest impact we found, recently
actually, was in moving all images, CSS, Javascript and other static
content off to the web server... especially when your doing AJAX and
your making numerous small requests vs. one or two larger non-AJAX
requests, not having to hit the web server makes a huge difference...
remember that in most cases, there is a small number of connections
available between the web server and app server (we had 5 I believe)
even though you may have 100 connections/threads available on the web
server (and probably app server). That's where we found the most
significant bottleneck... we're talking making an app twice as fast just
by moving static content off the app server!
4. Aside from the static content thing, this is the biggest point to
emphasize: you need to get your developers thinking a different way then
they probably are used to... they need to, for lack of a better way to
put it, trust the client more. For instance, we had developers that
insisted on putting objects in session, even though myself and other
senior developers were telling them it'd be better to keep things in
Javascript objects client-side... they would tell you now we were 100%
right :) This isn't a criticism of them though, when your used to doing
things a certain way, and they basically work well, you don't want to
change, especially given what many people have historically thought
about Javascript and client-side development. But once you get the
mindset changing, you'll see a really huge improvement in performance of
your apps because the fundamental design leads to better performance
naturally.
rgds
Rahul
Frank
--
--
Frank W. Zammetti
Founder and Chief Software Architect
Omnytex Technologies
http://www.omnytex.com
AIM/Yahoo: fzammetti
MSN: [EMAIL PROTECTED]
Author of "Practical Ajax Projects With Java Technology"
(2006, Apress, ISBN 1-59059-695-1)
and "JavaScript, DOM Scripting and Ajax Projects"
(2007, Apress, ISBN 1-59059-816-4)
Java Web Parts - http://javawebparts.sourceforge.net
Supplying the wheel, so you don't have to reinvent it!
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
