[zeromq-dev] Question about reliability in ZeroMQ

[白木勇矢]

Hello everyone,

I'm trying to use ZeroMQ Pub/Sub and Router/Dealer for my school
project. I have a question about reliability of these sockets.
According to the API Page(http://api.zeromq.org/), when queue reached
a high water mark and move to mute state, Dealer is going to block,
Router is going to drop, Sub I'm not sure, and Pub is going to drop
the message. But I cannot clearly see the behavior of each socket.

When Dealer send message to Router via TCP and Router is in mute
state, Dealer would be able to know this and resend message again
after some interval? If Router sends the message and Dealer is in mute
state and blocked, how Router is going to act?

Also when Pub sends the message to Sub via TCP and if Sub is in mute
state, how Pub is going to behave? If Pub wants to know whether the
message is correctly enqueued in Sub, PGM is going to solve this?

If someone would be able to answer these questions and tell me how to
avoid queue drops, I appreciate it so much.

Thanks,
Yuya