[Sunhelp] cachefs performance

[James Lockwood]

On Fri, 11 Feb 2000, bjf wrote:

> At my day job, I'm looking to implement a setup with a large backend
> cgi/java/db server and smaller frontend web servers.  With the concept I'm
> working with right now we'll be dealing with some regularly generated (every
> 5-10 minutes) static html pages, plus a whole lot of content which changes
> once a day or once a week, all of which somehow need to get onto the frontend
> web servers (which are likely going to be 4-5 Netra T1s - backend is a
> quad-cpu E450).
> 
> I've read a bit about cachefs, and think exporting the backend document
> tree and mounting it as the backend cachefs filesystem might work nicely, if
> cachefs works fairly well in a production environment.  We're right now
> doing on the order of 500,000 pageviews per day (~2M hits/day), but will
> likely be hitting numbers well over 2M pageviews during high-traffic events
> this year (ie Olympics).
> 
> Anyone used/using cachefs in a high(ish) volume situation?  Pros/cons/advice?

Cachefs can be a significant win in read-only applications, as long as
each page is accessed enough to compensate for the write hit on first
access.

For your application, however, I'd recommend going with a proxy web cache
solution for the front end.  Modern proxy caches are still significantly
faster than full featured webservers for serving static or near-static
data, and your data will be stored in a more optimized form on the front
end.  For the best results, you might want to use a cache hierarchy 2
levels deep with a single proxy cache/webserver sitting in front of the
E450 and the rest of the caches feeding off of that.

Many people have used this to great effect.  Both free and commercial
offerings are quite functional at this point.  Send me mail off-list if
you would like references or additional information.

-James