I am having a Sharepoint 2007, commerce server 2009, and SQL server 2008. My I create a Commerce server site template to create the sharepoint sites. After this I went to create the Site collection output cache profile. And I set the cache duration to 120 seconds. I applied this new profile to the all my site and sub-sites. After this I created webpart that simply ouputs the current system time. On a newly created page, I added this webpart, and refreshed the page. Every time I refresh the page, the webpart gives me different time. This imply that the cache is not working. Now, I went “view source” of my page in IE, and I could find that at the bottom of it it is written that the page rendered from a cached page. All the above senarios are for Anonymous user, to which i have applied the profile.

In your cache profile have you enabled "Check for Changes" ? This will check if the page has changed for each request, since your web part will be displaying the current time, the page will have in effect changed and so the cache will be updated and the new page served to you.

In your cache profile have you enabled "Check for Changes" ? This will check if the page has changed for each request, since your web part will be displaying the current time, the page will have in effect changed and so the cache will be updated and the new page served to you.