Dunno... just playing around with ØMQ for the sake of trying to figure out what all the sockets really do or don't do or whatever. There's a lot of information on http://zguide.zeromq.org/py:all ; it's almost just too much to deal with ... while at the same time, it leaves me wondering REP? PUSH? DEALER? ... WTF?
I don't really have any goals, not really, I just want to learn zmq, but how can I get anywhere with that without something to do?
So first, I'm going to make jzmq.StupidMessageBus or jSMB.
- everything should be authenticated (via local-CA certfificate signing?)
- no central server, just a few name hints of places to try first
- once connected, try to discover more nodes and try to connect to those until connected to the correct number of peers (by settings probably?)
- any message should broadcast to all hosts on the bus
I think we'll add more requirements later (many channels? routed messages, directed messages, API/shell attachment points…), but for now …
As I try to figure some of this out, I'm going to try to create a table of what these sockets are and how they do or what they be... I guess.
| Type | Endpoint | Direction | Pattern | out | in | mute |
|---|---|---|---|---|---|---|
| REQ | REP, ROUTER | both | send, recv, send, recv, … | round-robin | last peer | block |
| REP | REQ, DEALER | both | recv, send, recv, send, … | fair-robin | last peer | n/a |
| DEALER | ROUTER, REP, DEALER | both | unrestricted | round-robin | fair-queued | block |
| ROUTER | DEALER, REQ, ROUTER | both | unrestricted | ??? | fair-queued | drop |
| PUB | SUB, XSUB | uni | send-only | fan out | n/a | drop |
| SUB | PUB, XPUB | uni | recv-only | n/a | fair-queued | n/a |
| XPUB | SUB, XSUB | uni | send / recv-subscription | fan out | n/a | drop |
| XSUB | PUB, XPUB | uni | recv / send-subscription | n/a | fair-queued | drop |
| PUSH | PULL | uni | send-only | round-robin | n/a | block |
| PULL | PUSH | uni | recv-only | n/a | fair-queued | block |
I'm leaving out PAIR, SERVER/CLIENT, and RADIO/DISH. PAIR is for inproc multi-threaded communication and I don't much care about it. The rest are still in draft.
All my EARLS are Python-centric where possible.