How do you handle replacing/adding/removing memcached nodes in your production applications? I will have a number of applications that are cloned and customized due to each customers need running on one and same webserver, so i'll guess that there will be a day when some of the nodes will be changed.
Here's how memcached is populated by normal:
$m = new Memcached();
$servers = array(
array('mem1.domain.com', 11211, 33),
array('mem2.domain.com', 11211, 67)
);
$m->addServers($servers);
My initial idea, is to make the $servers array to be populated from the database, also cached, but file-based, done once a day or something, with the option to force an update on next run of the function that holds the $addservers call. However, I am guessing that this might add some additional overhead since disks are quite slow storage...
What do you think?
It's always better to define things like that in the source. Granted, you could use parse_ini_file() or something like that to read a configuration file. Really though, it belongs in the source. But if defined in an INI file, there aren't many security concerns such as code injection and the likes as opposed to defining your entries in PHP.
Since there are a few applications that might be reading the same INI file, you can put it in a common location that all applications have access to (using group permissions, for example). Actually doing that isn't really recommended.