Finally i got a book that is truly worth recommending! It is a very good book and i think every web developer should read it.
Book is a sort of a continuation of another good book High performance websites but to be honest i think i like this one more.
Book is very condensed, there is no wasted page in it. Information is well structured and you can see that authors prepared well for the publishing. Information is backed by a decent research and some of the tricks are really cool.
When you build PHP applications you need cache storage to keep your calculated data in. There are quite a few options and use case decides which solution is better.
I knew that APC is faster than memcached as there is much less overhead but I wanted to see how memcached would compare to APC user cache.
I had a chance to work a bit with a new page speed and JS mimification tool from google and i have to say its really cool.
The tool i am talking about is closure compiler and page speed and you can find it here
Web performance is not all about database calls and PHP speed. Its also about how many elements you have to be downloaded, in what order, how big are they, can they be cached, can they be compressed etc. Page speed helps you to figure out how to speed up the loading time not the html generation time. Pages consist of many js, css files as well as images. Knowing what causes delays is crucial to successful website performance optimization.
High Performance Mysql is hands down the best mysql book i have seen.
I would recommend it to everyone who wants to learn more about mysql, not only for gurus but for everyone. I would recommend it to sys admins and programmers. Especially if you are concerned by performance you should read this book.
Authors describes in details how mysql works, how to tune it, how to avoid benchmarking pitfalls and how to plan for scale.
Memcache is a great caching tool thats true. Unfortunately optimizing performance it sometimes works not in the way we would expect it to.
In general new versions of memcached are great and you should not expect many bugs but older versions like debian's 1.1.12 seem to have some issues. We could not upgrade yet but very soon we should run latest stable version.
So far we seem to have to restart memcache every few days on our servers as they get stuck. You are not able to set values - and there is no reason for it except that there has to be some bug. We also memcached crash ocassionally - but thats very rare.
The biggest gotcha is definitely how memcache is managing the memory.
My work requires me to work more on performance optimizations so i need to do some home work from time to time :-) lately i started getting deeper into memcache to learn its internal structure and algorithms used. I know i wont make survive without a simple and quick way of checking status and statistics of my memcache. As a result of last weekend i am happy to share a nice stats tool.