Koert,
 
it is very interesting observation.
 
Confirm there is no established TCP connection at port 5051 if run application in order 1 - 3 - 2.
If you want the thing working reliably you should do bind before connect.
So the issue is not in PUB/SUB vs. REQ/REP but connect/bind order.
 
If you do connect not bind in application 2 and change application 1 accordingly,
everything works perfectly.
 
Not sure if this is a bug or not  - hope 0mq developers can shed some light.
 
21.09.10, 22:17, "Koert Kuipers" <[email protected]>:

Hello all,

I ran into a problem while developing a server in python. Whena program is listening to both a REP socket and a SUB socket, usingmultiplexing (poll), messages from the publisher (which should arrive at theSUB socket) get lost. This seems to only happen if there are also messages arrivingat the REP socket, and typically all the messages from the publisher get lost.

 

My setup:

Windows XP (I also observed the problem on Ubuntu 10.04)

zeromq 2.0.7

pyzmq

 

The problem doesn’t always occur, and is somewhat hardto replicate.

 

I ended up convincing myself that there is indeed a problemby writing 3 little programs. Program 1 listens to REP and SUB socket, program 2only has a PUB socket and sends 1000 messages, and program 3 only has REQsocket and does 1000 RPC requests in a row.

 

When I start the programs in this order everything works asexpected:

Start program 1, then program 2 and then program 3 (program3 starts while program 2 is still working). Program 1 will report it received1000 messages on the PUB socket and 1000 messages on the REP socket.

 

But when change the order I get into trouble. I startprogram 1, then program 3 and then program 2 (program 2 starts while program 3is still working). Program 1 will report it received 1000 messages on the REPsocket but none on the SUB socket.

 

Best,

Koert

 

PS I attached the 3 programs. Hope that works.

 

 

 

 

 

 



--
Best regards,
Ilja Golshtein.
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