[ideal0227]

What is not true? 10x simpler, no?

There are two possibilities:

1. You misunderstood Paxos, probably confused that with RSM. For example, Paxos is just the leader election part of Raft. Superficially, it seems different from Paxos, but it what it is under the surface.

2. You implemented RSM incorrectly, probably missed some important features or optimizations. For example, log compaction, membership reconfiguration, pipeline, back pressure on execution, etc.

It is VERY important to differentiate Paxos and RSM. There are tons of optimizations you can do with RSM. But on consensus, there is ONLY Paxos today. Or you do it wrong or you invite something truly new.

[sriram_malhar]

There are two possibilities.

1. You underestimate my understanding.

2. You underestimate my experience.

I am sure you know this: both are comparable as a shared log abstraction. Once you have that, the state machine part is trivial. For the replicated shared log abstraction, you need to do the same kind of things in both the Paxos and Raft worlds. The latter is simpler to implement because the paper is written close to an engineer's understanding. i have written several versions of both, in production.

[ideal0227]

No, Paxos is not a shard log abstraction. Paxos is about agreeing on one value rather than a set of values in sequence. So my possibility 1 is true.

[sriram_malhar]

I can't edit my earlier response, but on second thought, we are both right. Is that consensus? :)

I think the difference in our stances arises from the two ways in which the term 'Paxos' is used. In the part-time-parliament paper, the single-decree paxos is the fundamental building block. I'm assuming this is what you think of as Paxos, and you are right in your assertion. It is defined as the fundamental act of consensus.

However, I have always viewed the single-decree protocol as a pedagogical device; a single write-once distributed register is useless in practice, so the multi-decree protocol is where it becomes useful, and to me is the point of the paper. I say this for a few reasons: a) state machine replication has been Lamport's focus since his early papers, including the 'time clocks and ordering' paper. (b) in engineering-oriented papers such as 'paxos made live', 'chubby' and so on, the term is used as a proxy for a replicated log. The reason for the many variants of Paxos is due to the underlying impulse that basic paxos is not sufficient in and of itself. You need some variant of shared log or equivalently, atomic broadcast.

So, we are both right in our ways. We can have consensus, as long as we sacrifice consistency of the definition of 'Paxos' :)

[sriram_malhar]

Are you speaking of Basic paxos?