Question

i’m trying to use mongodb as a network wide configuration storage. This the same app runs on multiple machines on the network, each pulls its configuration from its local mongodb. The
mongodbs are synced. What i would like is to get a callback/notification in all n-1 apps if one application changes any of the config values.
Is this kind of setup possible ?

(It would save me from doing the network transfer/syncronisation etc. myself.)

Answer 1

MongoDB doesn’t yet have triggers, but you can hook your application to tail off the oplog collection and do something every time a document is deleted (or updated, or inserted, etc.)

The 3 part blog post here might be helpful on how to do this :
http://www.kchodorow.com/blog/2010/10/12/replication-internals/