Sections 13 - 14.9 of the RFC 2616 HTTP 1.1 specification http://www.w3.org/Protocols/rfc2616/rfc2616.html
<snip> The Cache-Control general-header field is used to specify directives that MUST be obeyed by all caching mechanisms along the request/response chain </snip> -----Original Message----- From: Unmoderated discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] On Behalf Of Frans Bouma Sent: 12 October 2004 12:19 To: [EMAIL PROTECTED] Subject: Re: [ADVANCED-DOTNET] MiddleTier Caching was Abstracting SQL Isn't that caching header used to control proxy server caches? I.e.: when 500,000 desktop boxes connect to your website, not through a proxy, your pages will be rendered 500,000 times. I think the poster was asking for a caching solution on the webserver itself, so no matter what is used on the client side (or the route to the client side) the server is not under stess when the site receives a lot of requests Frans. > IIS5/6 are both capable of adding a cache-control header; > part of the HTTP > 1.1 protocol - ASP.NET simply adds this header when using the > OutputCache directive, to the outgoing HTTP stream - you may > notice that static items, such as images etc are always > cached by default by the IE cache on the client. > > Using the cache-control headers it's possible to force > content to be cached in several locations, ranging from > client, server and any intermediate point of presence server > (ISP cache/proxy) in the internet. > > ASP was designed to serve dynamic content not static content, > such as HTML/images. It's normal practice to try and offload > the serving of static content onto publishing servers i.e. > caching servers e.g. ISA server - therefore allowing IIS/ASP > to do what it's meant to i.e. serve dynamic content. > > Each virtual dir in IIS5/6 can be set to add cache-control > headers (this does not require ASP.NET and can be used for > any web application including VB6, PHP etc) > > You can set the cache-control header by looking at the HTTP > headers tab of your vdir - it's possible to set an absolute > time out, or minutes, hours, days etc > > I hope this helps, but beware caching too much content can > actually degrade system performance - the machine will use a > larger amount of resources and may take longer to look up the > cached page it may be quicker to simply regenerating it from > the originating server - you should test this before > employing a caching strategy. > > Regards, > Andrew > > Developmentor Instructor > Course Author > > > -----Original Message----- > From: Unmoderated discussion of advanced .NET topics. > [mailto:[EMAIL PROTECTED] On Behalf Of Frans Bouma > Sent: 12 October 2004 10:28 > To: [EMAIL PROTECTED] > Subject: Re: [ADVANCED-DOTNET] MiddleTier Caching was Abstracting SQL > > > Frans Bouma wrote: > > > To save webserver power because the website gets 500,000 > > hits per day? > > > Perhaps a page caching with 1 minute per page will help. > Often that > > > will give much more performance boosts than lowlevel > caching with a > > > lot of overhead. > > > > > This is what we often do, but when the cache invalidates, > those 500000 > > hits are wanting to update the cache and flood the db, I am > > exaggerating but you catch my drift :D Any one ideas how to prevent > > the flooding of the db (in a VB6 world) ? > > If a page cache invalidates, the first request will > hit the db, the second will get the cached version. > > But you can also use the system used by for example slashdot. > Say your webserver farm can render ALL the pages you want > caching for in 10 seconds. This means that if you re-render > all these pages every 20 seconds, your system will perform > nicely no matter how many hits your system gets, although > performance can degrade a little when more requests come in. > After the site is rendered, it is cached completely till the > next re-render (which is using a render to cache mechanism) > > The beauty of the system is that when extra > performance is required, you simply crank up the interval: > not every 20 seconds, but every minute you do a re-render. > > Frans. > > =================================== > This list is hosted by DevelopMentor. http://www.develop.com > Some .NET courses you may be interested in: > > Essential .NET: building applications and components with > CSharp August 30 - September 3, in Los Angeles > http://www.develop.com/courses/edotnet > > View archives and manage your subscription(s) at > http://discuss.develop.com > > =================================== > This list is hosted by DevelopMentor(r) http://www.develop.com > Some .NET courses you may be interested in: > > Essential .NET: building applications and components with > CSharp August 30 - September 3, in Los Angeles > http://www.develop.com/courses/edotnet > > View archives and manage your subscription(s) at > http://discuss.develop.com > > > =================================== This list is hosted by DevelopMentor. http://www.develop.com Some .NET courses you may be interested in: Essential .NET: building applications and components with CSharp August 30 - September 3, in Los Angeles http://www.develop.com/courses/edotnet View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentorŪ http://www.develop.com Some .NET courses you may be interested in: Essential .NET: building applications and components with CSharp August 30 - September 3, in Los Angeles http://www.develop.com/courses/edotnet View archives and manage your subscription(s) at http://discuss.develop.com
