JSON Library Benchmarks

As far as I’m aware, using Jason is the conventional wisdom in the Elixir circles for a while now.

In most benchmarks Jiffy tends to be the fastest of the well known libraries. Jason is slower but has more use throughout the community and its pure elixir. We use a combination of jiffy and jason at work and benchmark against our specific payloads.

That’s what I ended up seeing in the benchmarks.

One of my side projects right now is building a web server that can get faster performance than cowboy (I know, it’s a pipe dream). Part of that was choosing the fastest JSON parser, and when I went exploring the popular libraries, I saw that in every benchmark there were wildly different results, each favoring whichever library I was looking at, so I made my own little benchmark to see which was the fastest.

I know that Jason is the current standard, I use it when I use Plug or Phoenix, it’s one of my favorite libraries.

This was just a quick side project of mine to get a more definitive benchmark, since every library typically advertises the benchmarks that show their library to be the best, and I wanted to know which one was without any bias.

I’m curious - why is Jason the standard choice when jiffy has been around for ages (i.e. it’s stable and well-tested) and is much faster?

I can’t speak for @michalmuskala (the creator) but IMO the selling point is that it’s pure Elixir and has no native dependency. And that it’s stricter.

Especially if you deploy to various Docker and VPS configurations this can be a life saver since some VMs and hosting providers can be finicky when compiling native code. Not having to deal with various GCC / clang versions and distro-specific patches can make a huge difference.

Getting jiffy to compile isn’t hard. Shimming it into all of the existing libraries is more challenging.

Agreed, I am not saying it’s always hard, I am only saying that not using it gets you rid of one more potential deployment problem that will bite you just at the right night at 2:00 AM.

As a guy who usually works without devops and sysadmins around, I appreciate this a lot. Other people’s workflows vary of course.

It’s the same question I had, especially after my benchmarks. Jiffy has such a massive performance boost here that it just makes sense to use it. And it’s not like it’s an unknown library, it’s been established for a while as THE library in Erlang.

For my own uses I simply wrote a little Elixir wrapper around Jiffy so that I can make it look more Elixir-y, and still use Jiffy. It makes it a little easier to use Jiffy, which at the end of the day really isn’t that difficult.

Out of curiosity, what kind of deployments have you done where libraries that use NIFs are problematic?

My company has a few Elixir services in production, and they use some Erlang libraries and some NIFs as well, and we’ve never had any issues in deployments using Docker.

I feel like this might come off as mean, and I want to stress that I am not trying to be mean, this is genuine curiosity because I want to know if I might run into these issues in the future.