Architectural advice on connecting multiple diverse sites into a single community

I've been given a task to connect multiple sites of the same client into a single network. So i would like to hear an architectural advice on connecting these sites into a single community.

These sites include:

1. Invision Power Board Forum (the most important site)

2. 3 custom made cms-s (changes to code allowable)

3. 1 drupal site

4. 3-4 wordpress blogs

Requirements are as follows:

1. Connecting all users of all sites into a single administrable entity. With permissions changing ability, users banning etc.

2. Later on, based on this implementation I have to implement "facebook like" chat, which will be available to all users regardless of place of login.

I have few ide开发者_如何学编程as on my mind on how to go with this, but would like to hear some people with more experience and expertize than my self.

Cheers!

You're going to have one hell of a time. Each of those site platforms has a very disparate user architecture: there is no way to "connect" them all together fluidly without numerous codebase changes. You're looking at making deep changes to each of those platforms to communicate with a central database, likely modifying thousands (if not tens of thousands) of lines of code.

On top of the obvious (massive) changes to all of the platforms, you're going to have to worry about updates: what happens when a new version of Wordpress is released? You'd likely have to update all of your code manually (since you can't just drop in the changes). You'd also have to make sure that all of the code changes are compatible with your current database. God forbid one of the platforms starts storing user information differently---you'd have to make more massive code changes. This just isn't maintainable.

Your alternative (and best bet) is to have some sort of synchronization job that runs every hour or so: iterate through each user in each database and compare it to see if it both exists and is up-to-date in the other databases. If not, push the changes out. The problem with this is that it will get significantly slower as you get more and more users.

Perhaps another alternative is to simply offer a custom OpenID implementation. I believe that Drupal and Wordpress both have OpenID plugins that you can take advantage of. This way, you could allow your users to sign in with a pseudo-single sign-on service across your sites. The downside is that users could opt not to use it.

Good luck