My goal is to early flush the header part of my website while my php script is stitching the rest of the page together and sends it once its done. Important is that the chunks are sent compressed to the browser. (I am using Apache/2.2 and PHP/5.3.4)
Right now I am trying to achieve this by calling ini_set("zlib.output_compression", "On") in my PHP script. But if I use flush() anywhere in my script even at the end the compression won't work anymore.
Questions are:
a) By using this method zlib will flush the output buffer and send the compressed chunk to the browser once the size of this output buffer is reached?
b) If so is there any way to fine control when zlip will send my chunk not by just setting the internal buffer size of zlib? Default is 4KB.
c) Are there any good alternatives to achieve an early compressed flush maybe with more fine control regarding the time when I want to flush it? Maybe I am totally on the wrong path :)
It's been a LONG time since i had to use zlib compression on OB (more on why later). However, let me try and convince you to turn OFF zlib compression on OB in PHP. First of all, a little background to ensure we are on the same page.
HOW DOES OB WORK
Everytime php prints something, without OB it would be sent straight to apache and from apache to the browser. Instead, with OB, the output stops at apache and waits until the data is flushed (to the browser) or until the script ends and the data is flushed automatically. This saves quite a lot of time and resources when generating a page by buffering the Apache to Web Browser stage of the process.
WHY NOT TO USE OB COMPRESSION IN PHP
Why would you make PHP compress it? It should be the servers job to do such tasks (as well as compress js files for example). What you "should" do to drastically free apache to process php is to install NGINX as a front to the public. It's VERY easy to setup as a reverse proxy and you can even install it on the SAME server as php and apache.
So set NGINX on port 80, put apache on say 8080 (and only allow nginx to connect, but don't worry if you leave it public for a little time as it was already public and great for debugging to bypass nginx so no security issues should rise - but i recommend you don't leave it public for to long). Then make nginx reverse proxy to apache, cache all static files which offloads that from apache (because nginx serves them instead) meaning apache can do more php requests, and also get nginx to perform OUTPUT COMPRESSION ;) freeing up apache and php to do even more requests. As an added benefit, nginx can also serve static files much faster than Apache and Nginx also uses much less ram and can handle much more connections.
Even an nginx newbie could get nginx setup after reading a few tutorials online and complete everything i just said within 1 day. 1 day well spent as well.
Remember to KEEP output buffering ON however for PHP to Apache but turn zlib compression OFF on PHP and enable it instead on nginx.
