Posted by Al on 01/15/05 02:28

George Schlossnagle addresses exactly your requirement in his book "Advanced PHP
Programming".


Josh Whiting wrote:
> Dear list,
>
> My web application (an online classifieds server) requires a set of
> fairly large global arrays which contain vital information that most all
> the page scripts rely upon for information such as the category list,
> which fields belong to each category, and so on. Additionally, there are
> a large number of function definitions (more than 13,000 lines of code
> in all just for these global definitions).
>
> These global arrays and functions never change between requests.
> However, the PHP engine destroys and recreates them every time. After
> having spent some serious time doing benchmarking (using Apache Bench),
> I have found that this code takes at least 7ms to parse per request on
> my dual Xeon 2.4ghz server (Zend Accelerator in use*). This seriously
> cuts into my server's peak capacity, reducing it by more than half.
>
> My question is: is there a way to define a global set of variables and
> functions ONCE per Apache process, allowing each incoming hit to run a
> handler function that runs within a persistent namespace? OR, is it
> possible to create some form of shared variable and function namespace
> that each script can tap?
>
> AFAIK, mod_python, mod_perl, Java, etc. all allow you to create a
> persistent, long-running application with hooks/handlers for individual
> Apache requests. I'm surprised I haven't found a similar solution for
> PHP.
>
> In fact, according to my work in the past few days, if an application
> has a large set of global functions and variable definitions, mod_python
> FAR exceeds the performance of mod_php, even though Python code runs
> significantly slower than PHP code (because in mod_python you can put
> all these definitions in a module that is loaded only once per Apache
> process).
>
> The most promising prospect I've come across is FastCGI, which for Perl
> and other languages, allows you to run a while loop that sits and
> receives incoming requests (e.g. "while(FCGI::accept() >= 0) {..}").
> However, the PHP/FastCGI modality seems to basically compare to mod_php:
> every request still creates and destroys the entire application
> (although the PHP interpreter itself does persist).
>
> Essentially I want to go beyond a persistent PHP *interpreter* (mod_php,
> PHP/FastCGI) and create a persistent PHP *application*... any
> suggestions?
>
> Thanks in advance for any help!
> Regards,
> J. Whiting
>
> * - Please note that I am using the Zend Accelerator (on Redhat
> Enterprise with Apache 1.3) to cache the intermediate compiled PHP code.
> My benchmarks (7ms+) are after the dramatic speedup provided by the
> accelerator. I wouldn't even bother benchmarking this without the
> compiler cache, but it is clear that a compiler cache does not prevent
> PHP from still having to run the (ableit precompiled) array and function
> definition code itself.

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