Hi Dharmesh, Excellent question. In fact your question is one of the main reasons I wanted to build a dynamic page caching module. Dynamic means active, active means higher gains
One of the best things about page caching is that the more traffic you get, the more you will benefit from it which allows you to set the refresh rate even lower (refresh more often) and still get huge gains. In other words, if you have a forum that gets very little traffic, then the content isn't really changing much anyway. For instance, in your Forums example. With most forums there are usually lots of people reading the different posts, and only a few people actually changing those pages by creating new posts. And on a longer thread that has enough posts to get to a second "page", the first page rarely changes at all. So even in a forums environment it is only the newest content that is actually dynamic and the rest is more or less static. Most visitors are anonymous readers
Also, with typical websites, there are usually a lot more anonymous browsers of your content then their are people who are authenticated. Using the PageBlaster, pages are not delivered from cache unless the user is not authenticated. This works out very well by taking the biggest part of load off the server which in turn frees up those resources for people that are logged in. When a logged in user changes content (like making a post), the page cache is cleared automatically for that page. This may sound bad, because we are having to reuild the cache again every time someone posts, but in reality we are no worse off then not having caching at all when the cache gets cleared, and we immediately start gaining the advantage back from caching until the next post. That being said, I'm going to be doing further work to make sure the pages that are no longer dynamic do not expire as fast as the ones that are constantly changing. So in summary, even though your site may be very dynamic, that also means it is very active, which in turn means that you stand to gain more by caching then a site that gets little traffic. On the other hand, if your site gets very little traffic, then you can set your refresh rate much higher and still get the same relative benefits. Smaller is Better
One other thing about the PageBlaster is that it also does compression, and it does this before putting your pages in memory or on disk so you get another advantage there by not only delivering a smaller payload, but also storing a smaller payload. |