MongoDB Schema Design - Real-time Chat

Posted by Nick on Stack Overflow See other posts from Stack Overflow or by Nick
Published on 2010-05-29T21:02:38Z Indexed on 2010/05/29 21:22 UTC
Read the original article Hit count: 338

Filed under:
|
|

I'm starting a project which I think will be particularly suited to MongoDB due to the speed and scalability it affords.

The module I'm currently interested in is to do with real-time chat. If I was to do this in a traditional RDBMS I'd split it out into:

  • Channel (A channel has many users)
  • User (A user has one channel but many messages)
  • Message (A message has a user)

The the purpose of this use case, I'd like to assume that there will be typically 5 channels active at one time, each handling at most 5 messages per second.

Specific queries that need to be fast:

  • Fetch new messages (based on an bookmark, time stamp maybe, or an incrementing counter?)
  • Post a message to a channel
  • Verify that a user can post in a channel

Bearing in mind that the document limit with MongoDB is 4mb, how would you go about designing the schema? What would yours look like? Are there any gotchas I should watch out for?

© Stack Overflow or respective owner

Related posts about mongodb

Related posts about nosql