Yes. When a page changes, this fires an event, which I can catch and run some code. I would like that code to clear the cache for this specific page.
-----Original Message----- From: André Warnier [mailto:[EMAIL PROTECTED] Sent: Monday, December 01, 2008 2:50 PM To: users@httpd.apache.org Subject: Re: [EMAIL PROTECTED] Clearing cache selectively on Apache + mod_cache Ok then. So, how do you know that a given page changed ? I mean, if you don't want to wait, it means you have some way to know that the page has changed for which you don't want to wait, right ? Karim Zaki wrote: > This is exactly what is in place right now. I've written a filter in Tomcat > to set the "Expires" header, and Apache honors it. However, when a page > changes, I don't want to have to wait 24 hours for that change to reflect in > the cache, and I don't want to have to clear the whole cache either. I want > to selectively "push" the change to the cache by clearing that specific page > from the apache cache so that the next time it is requested, it will be > regenerated with the new content and cached. > > -----Original Message----- > From: André Warnier [mailto:[EMAIL PROTECTED] > Sent: Monday, December 01, 2008 1:36 PM > To: users@httpd.apache.org > Subject: Re: [EMAIL PROTECTED] Clearing cache selectively on Apache + > mod_cache > > I guess it all depends on your definition of "dynamic", and how you > handle this at the source. > > When your Tomcat generates an answer page, it can add HTTP headers that > indicate for how long this content is valid. If it doesn't, then by > default this means that the page is effectively "dynamic" (meaning that > each request could theoretically return a different answer next time). > What I mean by this, is that if your Tomcat added the right "Expires" > header in the first place (saying 24 hours), then you would have what > you seem to want, without having to do anything special in addition. > I would expect mod_cache at the Apache level, to take this information > into account, and serve the local copy instead of asking Tomcat again, > at least during these 24 hours. Then, when mod_cache realises that the > page's "valid until" date has passed, it will request a new version from > Tomcat automatically. > > So, is there any particular reason why the above scheme is not > applicable in your case ? > > > Karim Zaki wrote: >> But that would be like re-implementing mod_cache, wouldn't it? Apache is >> already doing this for me. It's caching the dynamic content, keeping it for >> 24 hours, and checking if it's in cache before requesting it from the >> back-end server. The only problem is that I need to sometimes clear certain >> pages from cache. >> >> -----Original Message----- >> From: André Warnier [mailto:[EMAIL PROTECTED] >> Sent: Monday, December 01, 2008 1:00 PM >> To: users@httpd.apache.org >> Subject: Re: [EMAIL PROTECTED] Clearing cache selectively on Apache + >> mod_cache >> >> Karim Zaki wrote: >>> Greetings all, >>> >>> I'm running Apache/2.2.10 (Win32) mod_jk/1.2.27 + mod_cache. I'm looking >>> for a way to clear the cache from Apache for specific URLs. I'm using >>> Apache to cache dynamic content that is served by Tomcat, and I would like >>> to keep the content (age) high (e.g. 24 hours) but still to be able to >>> clear the cache for specific pages when the content is updated. Is there a >>> way to tell Apache to clear the cache for a specific list of URLs? >>> >> Hi. >> I am not going to answer your original question, but I just have a >> couple of remarks based on your description above, and maybe a different >> way of thinking about this. >> >> You say that you want to cache dynamic content generated by Tomcat, for >> 24 hours. >> In other words, it is not really dynamic content, because for 24 hours >> your users are going to get the same unique version. >> >> If so, then why would you not generate these pages in advance, and put >> them somewhere on your Apache server to be served as static content ? >> Then each 24 hours you can do the same and refresh them from Tomcat. >> (This would be fairly simple to do using a script, calling something >> like wget or curl, or in perl using LWP). >> >> I believe it is fairly simple to configure your Apache in such a way >> that it will look first of this URL is available as a static page, and >> if not forward the call to Tomcat. >> (using mod_rewrite e.g.). >> >> >> --------------------------------------------------------------------- >> The official User-To-User support forum of the Apache HTTP Server Project. >> See <URL:http://httpd.apache.org/userslist.html> for more info. >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> " from the digest: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> >> --------------------------------------------------------------------- >> The official User-To-User support forum of the Apache HTTP Server Project. >> See <URL:http://httpd.apache.org/userslist.html> for more info. >> To unsubscribe, e-mail: [EMAIL PROTECTED] >> " from the digest: [EMAIL PROTECTED] >> For additional commands, e-mail: [EMAIL PROTECTED] >> >> > > > --------------------------------------------------------------------- > The official User-To-User support forum of the Apache HTTP Server Project. > See <URL:http://httpd.apache.org/userslist.html> for more info. > To unsubscribe, e-mail: [EMAIL PROTECTED] > " from the digest: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > > --------------------------------------------------------------------- > The official User-To-User support forum of the Apache HTTP Server Project. > See <URL:http://httpd.apache.org/userslist.html> for more info. > To unsubscribe, e-mail: [EMAIL PROTECTED] > " from the digest: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- The official User-To-User support forum of the Apache HTTP Server Project. 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