Gossiping serfs

Now that we understand a bit more about how a server peer set is established and operates, let's take a deeper look into what everybody is gossiping about. Again, if we start unpacking where the gossip protocol comes from, it utilizes the Serf (https://www.serf.io/) library, which is based on the Scalable Weakly-consistent Infection-style Process Group Membership protocol, which has thankfully been shortened to SWIM (http://www.cs.cornell.edu/info/projects/spinglass/public_pdfs/swim.pdf). We've jumped off of the Raft, and we've gone swimming!

Have a look at the following diagram:

Figure 2.16 – Gossip connections

All of the members of the Consul cluster, the servers and clients, are swimming in the same pool. This enables the distributed discovery of all members of the pool, their status, and—of course—the status of any services registered with the Consul clients. Although gossip is how all of the agents...