If Redis uses TCP it will bottleneck long before 0MQ does, because 0MQ uses a reliable-multicast protocol for communication over the LAN. As discussed in the li

If Redis uses TCP it will bottleneck long before 0MQ does, because 0MQ uses a reliable-multicast protocol for communication over the LAN. As discussed in the linked article, in the comments. Also, Redis is a centralized server and a single point of failure - 0MQ doesn't force you into that topology.