cache and webfarm

[Fabio R.]

I'm developing a web application that needs to support a webfarm scenario so
I've used a filecachedependency on a shared folder (for now, always in my
local machine) to clear cache on all application processes / server when I
update some data...
On some articles (like
http://msdn.microsoft.com/msdnmag/issues/02/12/WebFarms/) someone suggests
to use a webservice call on every server in the farm, this webservice simply
invalidate or update the cache.
My doubts are:
- is the filedependency on a shared folder (also used for filesession) a so
bad idea, can I have any problems using it?
- can the webservice method be more efficient?
- what happens if the servers with webservice are dual CPU (with 2 asp.net
process running)? Can be the cache invalidate on both with that method?
Thanks to anyone can give me an explanation, I'm not so expert in webfarm
scenario...
Fabio R.

 

[Bruce Barker]

couple issues:

1) access to shared folder - all the asp.net accounts must be a domain
account with access to the share. use app pools on 2003 for this.

2) file monitoring on a network share uses non-paged pool, and you can run
out. see:

http://support.microsoft.com/default.aspx?scid=kb;en-us;221790


-- bruce (sqlwork.com)

 

[Fabio R.]

About the second point:
tha app can get into trouble if more than 125 users try to read/write on the
UNC share at the same time or if IIS needs to monitor (to notify changes)
more than 125 files?
Thanks for your reply,
Fabio

 

[Robbe Morris [C# MVP]]

Look into ScaleOut StateServer as a way to manage this.
Not only does it handle web farm session management
quite well, it also provides a web farm cache management
api.

Read more and download an ASP.NET code sample:

http://www.eggheadcafe.com/articles/scaleout_server.asp

--
Robbe Morris - 2004/2005 Microsoft MVP C#
http://www.masterado.net