Symfony2 performance tweaking - apache

Question

Symfony2 was looking so promising, powerful and flexible. So we were going to use Symfony2 + mongodb for one of our projects. But it appeared too slow (Apache/2.2.25 + PHP/5.4.20). Currently the app is pretty simple. but I have noticed that the httpd.exe lads CPU up to 28% when some simple page is loaded. The page is quite lite - just user profile info and the list of his posts. I even can't imagine how hundreds of users can be served (not even talking about numbers like 100k users) if performance will not be much better.
For instance the CPU load is 2% when opening the heavy 'products' page of ActivationCloud account (which fetches a good amount of data) (PHP+Smarty+SQL).
After taking a look on Xdebug output, I have found that a gret deal of time 20% is utilized by ClassLoader->loadClass(...) - 265 calls
After performing the following steps:
*generated class map
php composer.phar dump-autoload --optimize
*installed and enabled APC
[APC]
extension=php_apc.dll
apc.enabled=1
apc.shm_segments=1
;32M per WordPress install
apc.shm_size=128M
;Relative to the number of cached files (you may need to
watch your stats for a day or two to find out a good number)
apc.num_files_hint=7000
;Relative to the size of WordPress
apc.user_entries_hint=4096
;The number of seconds a cache entry is allowed to idle
in a slot before APC dumps the cache
apc.ttl=7200
apc.user_ttl=7200
apc.gc_ttl=3600
;Setting this to 0 will give you the best performance, as APC will
;not have to check the IO for changes. However, you must clear
;the APC cache to recompile already cached files. If you are still
;developing, updating your site daily in WP-ADMIN, and running W3TC
;set this to 1
apc.stat=1
;This MUST be 0, WP can have errors otherwise!
apc.include_once_override=0
;Only set to 1 while debugging
apc.enable_cli=0
;Allow 2 seconds after a file is created before
it is cached to prevent users from seeing half-written/weird pages
apc.file_update_protection=2
;Leave at 2M or lower. WordPress does't have any file sizes close to 2M
apc.max_file_size=2M
;Ignore files
apc.filters = "/var/www/apc.php"
apc.cache_by_default=1
apc.use_request_time=1
apc.slam_defense=0
apc.mmap_file_mask=/var/www/temp/apc.XXXXXX
apc.stat_ctime=0
apc.canonicalize=1
apc.write_lock=1
apc.report_autofilter=0
apc.rfc1867=0
apc.rfc1867_prefix =upload_
apc.rfc1867_name=APC_UPLOAD_PROGRESS
apc.rfc1867_freq=0
apc.rfc1867_ttl=3600
apc.lazy_classes=0
apc.lazy_functions=0
expected a miracle after it but it did not happen.
*enabled APC class loader - in Symfony\web\app.php uncommented
/*
$loader = new ApcClassLoader('sf2', $loader);
$loader->register(true);
*/
The ClassLoader->loadClass(...) got better 'Self' is 11 instead of 21
Frankly speaking I was shocked by what I saw in xdebug :( a lot of repetitive calls like Container->get(...) -317 calls, DocumentManager->getClassMeataData(...) - 301 calls. Totally more than 2k of function calls. Hard to believe that.
These bundles are installed:
class AppKernel extends Kernel
{
public function registerBundles()
{
$bundles = array(
new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
new Symfony\Bundle\SecurityBundle\SecurityBundle(),
new Symfony\Bundle\TwigBundle\TwigBundle(),
new Symfony\Bundle\MonologBundle\MonologBundle(),
new Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle(),
new Symfony\Bundle\AsseticBundle\AsseticBundle(),
new Doctrine\Bundle\DoctrineBundle\DoctrineBundle(),
new Doctrine\Bundle\MongoDBBundle\DoctrineMongoDBBundle(),
new Sensio\Bundle\FrameworkExtraBundle\SensioFrameworkExtraBundle(),
new HWI\Bundle\OAuthBundle\HWIOAuthBundle(),
new Knp\Bundle\MenuBundle\KnpMenuBundle(),
... our bundles ...
);
if (in_array($this->getEnvironment(), array('dev', 'test'))) {
$bundles[] = new Symfony\Bundle\WebProfilerBundle\WebProfilerBundle();
$bundles[] = new Sensio\Bundle\DistributionBundle\SensioDistributionBundle();
$bundles[] = new Sensio\Bundle\GeneratorBundle\SensioGeneratorBundle();
}
return $bundles;
}
It was sad to find that Symfony2 got one of the worst benchmark results among others php frameworks http://www.techempower.com/benchmarks/#section=data-r8&hw=i7&test=json&l=sg
At the same time Francois Zaninotto said in his blog http://symfony.com/blog/who-really-uses-symfony that Yahoo uses Symfony2 for the bookmarks service, tried some apps form the list http://trac.symfony-project.org/wiki/ApplicationsDevelopedWithSymfony - they are not looking slow also on Quora http://www.quora.com/Who-is-using-Symfony2-in-production its spoken that dailymotion is using it as well.
How to make the performance acceptable?

Answer 1

Got Symfony working x10 faster after adding the
realpath_cache_size = 4096k
to php.ini

Answer 2

First you should use linux (you mentioned https.exe so I think you are using windows). Than you should use nginx instead of apache and php-5.5 with fpm instead of mod_php. Opcache instead of apc (by the way apc.stat should be turned off). Doctrine caches should be turned on and than you should use http caching wherever you can. (You can view packagist's code for some hints.)