November 2011 – Stuff Yaron Finds Interesting

State diagrams for Paxos made simple

I was reading through Paxos made simple and I really wished there were state diagrams to help explicate the protocol. So I wrote them up and share them below. Please keep in mind that the diagrams just explore naive Paxos, that is single value, no distinguished proposer or distinguished learner. So this version of Paxos is pretty useless in practice but it completely captures the core mechanisms that make Paxos work (with the exception of how to pick a distinguished learner). Please note that this article is intended to be used by someone going through Paxos made simple. It is an adjunct, not a replacement.

Wrapped or Native Paxos?

So let's say I want to build a nice highly consistent multi-data center store, something like Megastore. Most everyone at this point has something like Bigtable already deployed in their data centers. What they typically don't have is a way to keep different instances of their table stores guaranteed consistent with each other across DCs. Megastore steps in to address this issue. But this begs a fundamental question - what's better, to wrap a Paxos coordinator on top of existing table stores or to build a new Paxos native storage service?

To rent or buy a house?

Should we rent or buy a house? A fairly quick and easy rule of thumb is (Price of a new home)/(monthly rent for equivalent home*12). As Dean Baker argues if the result is 15 or below then it makes financial sense to buy, otherwise renting is cheaper. For those who want more control over the calculations see the New York Time's rent vs buy calculator. My own settings for the calculator are give below.

Parallels 7 vs VMWare Fusion 4

I use a VM on my mac to run Windows for the sole purpose of using remote desktop to my work laptop. Yes, I know that Microsoft offers a free RDC client for the Mac. But the client doesn't support multiple monitors on a mac and that's a show stopper for me. I've been using VMWare Fusion 2 & 3 for a bunch of years now and I can't say I was ever really happy with it but it seemed to do the job. But I recently compared VMWare Fusion 4 to Parallels 7 and for my use case Parallels 7 is slightly better than VMWare Fusion 4 and with Parallel's upgrade offer for VMWare Fusion 3 users it's a no brainer in my opinion to switch to Parallels 7. So I have. More details below the fold.

Social Security is doing fine

One of the discussions I have with friends that most seems to confuse them is when I say that Social Security is in great shape. They take it as an article of faith that Social Security is doomed. Now while I've long argued that Social Security will end up means tested this isn't because the system doesn't work or is running out of money, it's rather my own belief in how politics will play out in the country. But regardless Social Security is doing fine now and into the foreseeable future. Salon recently had a reasonably simple article that explains why things really are fine and provides links to more in depth information for those who care.