Erlang JSON libraries: serialization performance?

Question

There are a number of JSON libraries available for Erlang, and it's not clear to me which have the best performance characteristics (and, secondarily, ease of use), especially for erlang-to-json serialization.

My use case requires both JSON parsing and serialization, but the Erlang code will probably be producing at least two orders of magnitude more JSON output (i.e. serialization) than it will receive input.

For reference, the libraries I know of include the following (and there may be others I haven't found):

• mochijson
• mochijson2
• erlang-rfc4627
• eep0018

Answer 1

I use rfc4627.erl (I stumbled upon it, and performance has not been an issue)

However, I do expect the different native erlang libraries to perform similarly well. They share ideas (as witnessed in the code comments). AFAIK mochijson and rfc4627 share the same source erlang format.

eep018 is C, and as it is striving to implement ... hrm ... eep-0018, the term_to_json native encoder that might be included in a future version of Erlang. Never tried it and doesn't seem actively maintained.

My final recommendation is go with mochiweb's mochijson(2). It is the de facto standard and actively maintained, used by, among others, CouchDB and Facebook.

As for choosing between mochijson and mochijson2, this might help you.

Answer 2

I've been using jsonerl lately. It's based on mochijson2 and is much more easy and intuitive to use.

Answer 3

Try https://github.com/si14/erl_json_test erlang json benchmarks. It included benchmarks for:

• List item

• JSONX

• Jiffy

• Mochijson2

• JSX