document DNS SRV record options - Python

For the appropriate section of any development and deployment docs, please add a section about DNS SRV records. Optionally, an administrator can have a set of records which list a few or all of the hosts in their cluster such that applications, mainly client libraries, can lookup hosts to bootstrap.

I'll attach a bit more info from Michael.

While this isn't a feature of 2.x including 2.5, it should be covered there since it's part of cluster administration. The feature is really something to be added to all of the client libraries.

Brett commented (which we agreed to):
Also, just to clarify the logic we have determined so far:
We would sort through the list of nodes by priority, where lowest priority number means highest priority. Then for all nodes of an identical priority, we would perform a weighted randomized picking of a node from that group. If the first choice fails, we will again weighted randomly pick a new node, while staying within the existing priority group, and ignoring the just-failed node. Once we have exhausted checking all servers of a specific priority, we would then go to the next priority group of servers and do the same thing.