Distributed Shared User DB Discussion

Mouton · 12-09-2003, 11:17 AM

Was wondering if anyone (dark?) had thought about how a distributed shared user db module would work..?

ie, not a single db with which all servers sync, but a module that propagate local changes to all servers.

I think using a single db is a little too dangerous... creates a single point of failure...

Any thought on how a distributed system should work ?
I didn't dwelve the how and what of all the users and groups functions in modules, but i'd guess there's one for each user or group modification that happens.

I thought to use transactions objects, which would contain the actual modification, the origin and destination servers, the delivery status for each destination server(s) and maybe a priority value and some other params...
Each transaction would then be pooled, and the pool would be propagated to all destination servers at regular interval, depending on the priority value of the transaction...

So basically, each function in the user and group module would create transactions objects, save them to disk, and a timer would propagate those to everyone.

Another way to do it would be to give each server a list of all the other servers, and at regular interval, they would 'pull' all transactions since last communication from 'alive' servers. This would help deal with dead servers; when they come back up, each server would pull all the new transactions from it since last communication, so nothing would be lost.

How does that sound ? Does it fit the users&groups module architecture ?

Any suggestion / comments about distributed system like that are welcome.