[Makumba-user] [ITD] page caching

[Egbert T. <e.t...@st...>]

#mak-user in cc.

hi ITD!

I made a class for caching pages. The idea of it that pages that don't  
depend on which user is logged in, on the weather, or on the exact time  
might not need to be recomputed every time it is accessed. If the exact  
same information is sent to everybody requesting a page, why not save the  
page itself instead of computing it with lots of mak:values and db  
accesses every time? So, in short, this is a method of optimisation.

The class saves a different page for every different query string that a  
page gets passed. This allows you to put caches on pages even if they  
might display different information in different cases.

I tried it make it as easy to use for JSP authors as possible, and made  
some documentation inside the class file. If you're interested, please  
check out  
http://tequila.best.eu.org/egbert-k/classes/org.eu.best.util.PageCache and  
give me some comments or whatever.

I started making it (jsp-based at first) for pages that allow local  
webmasters to import information like the BAS event list into their  
websites automatically, and figured that that could easily lead to a very  
heavy server load. But then, after some feedback from Rudi, we figured it  
might be more widely applicable. So here :-)

Joao already expressed an interest in it for a task of his, so maybe it's  
a good idea to already put it into production quite soon, even if I  
haven't finished the local webmaster tools thingy yet. So, feedback please  
:)

One thing that I see that could maybe become a problem is that the cached  
pages are saved inside the server's memory. The event list page is easily  
30kb, and for multiple different query strings that page would be saved  
multiple times. If we start doing this thing a lot, we might get into  
quite some megabytes. Does some server guru know whether this would make a  
problem? Or is it swapped automatically? Or something?

-egbert

ps. a page that works with it is  
http://tequila.best.eu.org/egbert-k/www/localWeb/eventList.jsp - try  
reloading the context, and you'll find a <!--computed.--> comment on top  
of that page. Reload the page itself only, and the <!--computed.-->  
comment is gone. Note that the page itself is an outdated and  
work-in-progress thing, please don't look at the content of it :-)