Contemplating the idea of moving a collection of sites (80+) into a wordpress network. Before doing so, I have a couple of questions I'm trying to answer and havent quite been able to find an answer to yet. Hoping someone in the community can chime in and/or point me in the right direction.
1. How many sites are you hosting?
2. What does your technological infrastructure look like? Load-balanced MySQL server instances + load-balanced web server instances? Single MySQL server + single web server instance?
Essentially, I'm trying to gauge where the break point is. How many wordpress sites can a single MySQL instance realistically handle before I'll need to split it out into a load-balanced set-up? Our web servers are already load balanced.
3. How do you manage themes? It appears that themes have to be installed at the upper/parent level and then enabled for each site. Each site can be given the ability to use a theme, but does not have the ability to edit the theme. Child themes (http://codex.wordpress.org/Child_Themes) appear to be a possible solution, but even then, it looks like the users arent able to edit the child themes from within wordpress and would need some level of file access to make modifications. Not ideal since I would then have to manage users/access in both wordpress and on the web server.
4. How do you manage plugins? Like themes, it appears that plugins have to be installed at the parent level, and then enabled for child sites. Do you have a set group of "approved" plugins and those are the only ones allowed? Do you have a process for site owners to request a plugin be installed? What about those who want to develop their own custom plugin?
5. Any warnings/gotchas when it comes to running a wordpress network you wish someone had told you before you started?
Thanks in advance for any advice/insight you can give me.