omq-qos

https://github.com/zeromq/omq.rb

Experimental Quality of Service plugin for the OMQ pure-Ruby ZeroMQ library. Adds per-hop delivery guarantees: QoS 1 (at-least-once), QoS 2 (exactly-once with peer pinning and dedup), and QoS 3 (exactly-once plus application-level COMP/NACK), using ACK/NACK command frames and xxHash message identification.