quinthar

I had some free time this holiday season and wrote up a blog post about how we use NUMA balancing on our 384-CPU, 6TB monster servers to keep the site humming reliably (and some of the challenges we've had to overcome). It's pretty low level, but I found there wasn't a lot of good info on how to optimize for high core-count servers, so I thought I'd share some experience. Enjoy!

we have been using this page locking technology for quite a while now and it works incredibly well. Having both read and write concurrency is super powerful and scales fantastically.

It's scales so perfectly we are deploying it across 3 datacenters, each with four 384 core machines with 3 terabytes of RAM. I can't speak highly enough about sqlite and the team behind it.

Expensify is powered entirely using sqlite (inside bedrockdb.com) and it is freaking amazing.

At Expensify we have been astonished by how easy it was to set up -- as simple as ssh -- and its incredible performance relative to OpenVPN. It's night and day due to it's multi threaded design, meaning it doesn't have the same single cpu bottleneck as OpenVPN. It's clearly the future.

I think a big challenge (and perhaps the root problem) is weighing the relative importance of different relative changes. Car deaths are down 97%, but suicides are up 30%. On balance, are things getting better or worse? (I'd say that car deaths are by far more common so the reduction there is more significant, but suicides are probably more directly correlated to happiness that car accidents...)

I'm more persuaded by the optimistic perspective, personally, but these are great contrasting pieces to highlight that it's not a slam dunk.

This is a much, much better rebuttal than the other one. Thanks!

Hmm how is this a good rebuttal? I haven't read the book, but the original article is based primarily on clear assertions of fact and statistics. A "good rebuttal" world presumably show that those stats are wrong, or at best misleading. But John's rebuttal is just a bunch of ponderous, abstract philosophy, with the most compelling part (and it's not very compelling) being:

"Much of its more than 500 pages consists of figures aiming to show the progress that has been made under the aegis of Enlightenment ideals. Of course, these figures settle nothing. [Uh, of course? Care to elaborate?] Like Pinker’s celebrated assertion that the world is becoming ever more peaceful – the statistical basis of which has been demolished by Nassim Nicholas Taleb [Oh snap! It was demolished by this dude I've never heard of, using reasoning that isn't provided? Dammnnnn, sick burn] everything depends on what is included in them and how they are interpreted. [Alright, I'm ready for you truth bomb]

Are the millions incarcerated in the vast American prison system and the millions more who live under parole included in the calculus that says human freedom is increasing? [Um, are they not? Or are you asking me to do the homework to see if your point has merit?] If we are to congratulate ourselves on being less cruel to animals, how much weight should be given to the uncounted numbers that suffer in factory farming and hideous medical experiments – neither of which were practised on any comparable scale in the past? [Good question... that you decline to answer]"

Basically: "X is misleading, because what about Y?" I don't know man, can you just tell me rather than leaving me guessing? It would be more compelling if he did his own homework rather than leaving his sucker punch as an exercise to the reader.

I think the original article is far more compelling than this so called rebuttal.

Fyi, Expensify uses sqlite as it's primary database in a HA clustered way, see bedrockdb.com for more details.

Well if the rules are:

- Libraries must be usable from C or C++, ideally both

- Libraries should be usable from more than one platform (ideally, all major desktops and/or all major mobile)

- Libraries should compile and work on both 32-bit and 64-bit platforms

- Libraries should use at most two files

Then ya, I think it'd fit. I'm not sure why size matters here: the goal is to have libraries that are easily embedded. Anyway, I was mainly curious for the reason. If size is the reason, then that's that. Thanks!