Of course, but zeromq makes it feel like you don't. It provides a message massing system that you pass messages into on one end and they magically pop out the o

Of course, but zeromq makes it feel like you don't. It provides a message massing system that you pass messages into on one end and they magically pop out the other. If the network is slow, congested or down it'll cache messages locally until it can reconnect and send them. The problem is you don't know what's going on and if the local cache fills up it'll silently drop messages. In some use cases that's perfectly fine- it depends on your application. Zeromq is great for some things - it's super flexible and FAST. It's just not, on its own, durable. If you need durability you have to build it on top. Doable, just not free.