Redis is great, maybe memcached would serve better for this pupose as some of the comments have mentioned. I just want to point out one thing about his multiple

Redis is great, maybe memcached would serve better for this pupose as some of the comments have mentioned. I just want to point out one thing about his multiple count queries per page. You can also do a grouped count query in a single query, by using something like: SELECT COUNT(*) FROM comments WHERE GROUP BY post_id; From that he gets an array of all the counts, so he can look those up easily. And that result can also be cached as well, of course.