prime aip instance after an auto-restart

[Lukas Kahwe Smith]

Hi,

I read the following comment:
"AiP workers die when PHP's memory_limit is exceeeded, and AiP will then restart them."

http://news.ycombinator.com/item?id=2544061

Now obviously after a restart the instance will perform slower as classes need to be reloaded etc. Is there a way to hook in some priming script that must be run before that particular AiP instance may be used again. I am mainly thinking about l loadbalanced setups where I can afford to keep a server out of the rotation in order to prevent latency spikes for users.

regards,
Lukas Kahwe Smith
m...@pooteeweet.org

[Alexey Zakhlestin]

Usually, application is represented by object of a class, which has __invoke() method. But, this class also has __construct(), which can be used for any kind of initialization. That's exactly what we use in all of our setups.

See example: https://github.com/indeyets/appserver-in-php/blob/master/examples/new/MyApp.class.php

Is that enough? Or you need something more complex?

[Lukas Kahwe Smith]

No, I guess that should be sufficient.
One thing though, does the AiP instance block while the constructor is executing?
if you start doing a lot of work in the constructor this could become a problem. Then again I guess one could then simply as a first step remove the given server from the loadbalancer, do the priming and then readd the server to the loadbalancer. however i guess this would all lead to one poor request that caused the memory overflow to wait ages for a response? wonder if there is a graceful way to forward that single request to a different server.

[Alexey Zakhlestin]

Well… usually, AiP works using pre-fork model, with child-processes starting to accept connections after initialization is finished.
I don't see why there should be any slow requests (less active workers = less requests per second, but request-speed should be the same)

The only possible reason for the slow request is if some initialization happens lazily during request-processing, and not in constructor.

[Lukas Kahwe Smith]

ah ok .. so as long as i do the priming inside the constructor i am fine? sounds good .. even great! :)