Virtually every open source OS and project on the web that uses encryption relies on OpenSSL. Yet they only get a few thousand a year in donations. Time to change that if we want better code: http://www.openssl.org/support/donations.html
Google and others have published several whitepapers showing benchmarks where tuning tcp/ip on servers can really help web browsing performance.
One of these important tweaks is known as IW10 which improves the tcp/ip congestion window by reducing ACKs (initally sending 10 packets instead of only 3) and is enabled by increasing initcwnd and initrwnd.
Unfortunately those on CentOS (one of the most popular linux production distributions) were not able to take advantage of this – until this weekend when CentOS 6.4 was shipped.
CentOS 6.3 could change initcwnd but NOT initrwnd (RWIN) which requires a kernel > 2.6.33
CentOS 6.4 is 2.6.32-358.0.1.el6 (Red Hat 4.4.7-3) so the feature has been backported
Here’s how to take advantage of IW10 on CentOS 6.4
Google recently opensourced an interesting little project in C called ZOPFLI to try to get the most compression possible out of gzip which is one of the only universal compression available in browsers.
This is useful for things that are compressed once and served many times, for example jquery, stylesheets, etc. But in my testing, Zopfli only does very slightly better than 7zip’s ultra gzip compression set at mx9, and zopfli takes much much longer. It’s an interesting experiment but perhaps pointless.
If you want to try it, you can get it at:
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There is still another week of voting left before it becomes official on March 7th but the results are pretty much complete. PHP 5.5 will definitely integrate Zend Optimizer Plus opcache, built right into the distribution.
This is a good thing for the future of PHP but will require some changes for webhosts.
Since even PHP 5.4 is not widely adopted yet, we are talking 2015 for the masses.
But you don’t have to wait for PHP 5.5, you can replace APC, Xcache and eAccelerator immediately with Zend Optimizer Plus via the newly opensourced code and I’ve made a free control panel for it. Works fine on PHP 5.3 and 5.4 and you’ll typically see a minimum 10% performance boost on busy websites over those other opcode caches because of it’s extra optimization passes.
In celebration of Zend open-sourcing their Optimizer Plus opcache for PHP, I whipped up a quick’n’dirty control panel just now. There doesn’t seem to be any other one? I wanted to learn and review its behavior a little more closely, to compare it to APC, Xcache and eAccelerator opcode caches.
(update: Version 0.0.4 now adds file grouping / sorting )
Code is a bit nasty in this early version because I did it in an hour. There is only limited info available about the cache state and I am still learning some of its caveats like it doesn’t actually store the file cached time but the file’s physical timestamp (probably to just see if the file has changed so it can recache it).
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