Why use Paxos instead of Raft?

I used to work in the orbit of a distinguished eng at AWS who was famous for saying something to the effect of, "At the bottom of any scaled distributed system is either Paxos, or a bug."

Interesting reasoning! I had a similar thought about why raft doesn’t allow observers the other day.<p>I used observers with Gluster previously and went from annoying split brain scenarios to flawless clusters just by adding a few, and their resource usage was basically nothing.

The author is here, happy to answer questions if any.

Great write up! I don&#x27;t have much practical experience with Paxos&#x2F;Raft other than coursework. I&#x27;m curious, if I wanted to insert a row into a table, what is the overhead of all these extra nodes in the insert operation now compared to a single table?<p>I realize the answer depends on how big the cluster is, what state it is in at any given moment etc, but I&#x27;m happy to accept back of the envelope calculations&#x2F;estimations!

So would using Neon negate the need for something like Citus for scaling out a postgres database?

Is there a difference between &quot;observer&quot; and &quot;witness&quot;? I&#x27;m used to the witness terminology from old literature and also from the Megastore paper, in which a <i>witness</i> votes in the Paxos election and stores the only the WAL.

I&#x27;m curious how many nodes end up in the consensus group, presumably you don&#x27;t want more than 3 because throughput scales 1&#x2F;N, unless their implementation can alleviate that significantly.

This is a great writeup, thanks. It will be very useful if y&#x27;all could add a post comparing neon with citusdb in terms of functionality, performance and operations.

Every time I see Neon I think this is about KDE.