Evaluate connection pooling options

[oubiwann]

@arpunk offered some great suggestions in his comment here, including:

• https://github.com/fishcakez/sbroker
• https://github.com/devinus/poolboy
• https://github.com/seth/pooler
• https://github.com/leo-project/leo_pod
• https://github.com/uwiger/gproc/blob/master/doc/gproc_pool.md
• https://github.com/okeuday/varpool

Note that any support provided by kanin should be general and pluggable -- not a pooling solution per se, but rather a general mechanism for supporting whatever users decide they want to use with kanin. It may be that, in the end, what kanin provides is some documentation on how to do this with one or two example libraries, to get the user started, and that's it.

See also the other link he provided, Fred's excellent article on the topic:

• http://ferd.ca/handling-overload.html

Part of epic #27

[arpunk]

sbroker is IMO one of the best ones and fits the goals. But if the user is the one who decides then I think it's best to point them to the available solutions instead and avoid pooling. All the wrappers/frameworks offers some kind of pooling strategies though.

Maybe we can just offer optional pooling backed by sbroker and some backpressure mechanisms and let the user enable/disable in configuration options.

[oubiwann]

+1