Re: APC & __autoload & webclusters

Richard Lynch schreef:

On Thu, February 21, 2008 9:27 am, Jochem Maas wrote:

1. __autoload & APC I have been STW to try and find a definitive answer as to whether using __autoload with APC is a bad idea ... and if so why? ... I can't find that definitive answer, can anyone here state whether this it's an absolutely bad idea to use __autoload with APC? (I need to speed up an app that currently loads in pretty much everything on every request ... and it's impossible to untangle the class interdependencies, in the time I have, and thereby load only what is absolutely needed, when it's needed ... so I want to give __autoload() a shot in order to minimize what classes are loaded.

If it's that inter-tangled, then I would hazard a WILD GUESS that the __autoload will still end up loading everything...

but not on every request ;-) ... I do use output caching, and I know not everything is actually used in every request. I'm being optimistic and hoping it has a marginally positive effective on average request processing time.

2. webclusters & APC I'm building a load-balanced cluster for the same app ... a certain times new data is imported from a thirdparty system after which some APC cached data needs to be cleared, in the same vein I occasionally roll out a new version and then the APC opcode cache needs to be cleared (each webserver in the cluster has it's own APC cache obviously). now I'm stuck with the problem of how to trigger the cache clearance on all servers ... Greg Donald already mentioned the ruby based capistrano for executing commands on multiple remote servers and I'll be using that to manage things like cache clearance, webserver restarting, etc on all the webservers ... BUT I have found that it is not possible to control the APC cache of php_mod from the CLI version of php, they apparently use different APC caches. it seems that the only way to control the APC cache of mod_php is via a web interface. APC ships with the very handy apc.php script but this is hardly a decent way of controlling/clearing the APC cache of multiple machine programmatically. Am I stuck with one of: 1. doing a graceful restart of all servers (which causes APCs cache to disappear)?

Yes, that should work.

I know - but it's a rubbish solution because it offer no control as to what is cleared from the APC cache, sometimes I want to clear opcodes, sometimes user-data, sometimes both ... graceful means being forced to clear everything.

2. writing a cmdline script that performs a URL request to a copy of apc.php that is reachable via each webserver in order to clear/manage the APC cache?

Yes, but obviously password-protect it to avoid DOS.

yeah - think this is the route I have to take somehow .. I'm going to look into running a seperate vhost only available via 127.0.0.1, with a pwd on it and then write a little script that can control the apc cache via said vhost from the cmdline ... the cmdline script would then be controlled remotely via ssh using the coolness that is capistrano (http://www.capify.org/)

or is there another way that I can control the webserver's APC cache from the cmdline?

One would think there would be some kind of USR_* signal that can be sent through Apache to APC to clear cache...

One would think that there was something like this indeed - I cannot find it, but then there must be something ... I assume, for instance, that Yahoo!** occassionally see fit to clear APC caches on more than one machine and I doubt Rasmus sits there and opens a browser to run apc.php on each one ;-) ** is it too early to say 'MicroHoo!' ?