Networked Broadcast Messaging

[David Bolen]

"squishywaffle at gmail.com" <squishywaffle at gmail.com> writes:

> * Machines can come and go. Since messages are not directly sent to a
> specific IP address from our Python script, the messages are simply
> broadcasted to those who are there to listen. If nobody is subscribed
> to the message type being sent, nothing happens.

What sort of delivery guarantees are you looking for if there is in
fact a machine that is trying to listen to a particular message or
message group?  Is it ok if someone is listening for a certain type of
message, is it ok if it misses one that is sent?

If you do simple direct broadcasting (e.g., UDP), you'd need your own
reliability layer above that if you cared if the message actually got
to an intended destination if that destination was present.

If you want better guarantees, you might look into a distributed
message bus like Spread (http://www.spread.org/) or perhaps a
messaging protocol like XMPP (http://xmpp.org/) through its PubSub
extension.  Both have Python interfaces, though I have no personal
experience with either.  But perhaps that will also give you some
terms or starting points for searching for other options.

-- David