Jeremy Andrews wrote:
- The cache has a much higher miss rate than expected on drupal.org at least because the site is constantly being crawled by spiders. Pages that are visited often get re-cached quickly after a wipe, but this doesn't happen for the random access pattern that is common for spiders and also for posts reached through searching.
Yes, this is true. And I remember the data you and Dries came up with. However I still get a large boost from the cache. I believe this is because much of the anonymous traffic is due to links from other news sites, and thus the same page is loaded many times in rapid succession. Thus, only a percentage of page loads benefit from the cache, but it's a significant enough percentage to have a noticeable affect on performance. Disabling the cache (or flushing it every second) has a negative affect on performance.
Caching helps a lot. That said, developers should _not_ rely on pages being cached. The cache is no substitute for badly performing code because 50% of the time, the badly performing code is executed.
- Any aggressive caching should be implemented as an optional feature as it is useless for small sites. Perhaps we could change the cache option into three states: "No caching" "Mild caching" "Aggressive caching".
Yes, I agree. But is there interest in merging an agressive type caching mechanism?
Yes, there is. -- Dries Buytaert :: http://www.buytaert.net/