Requests with big payloads are extremely slow due to bug in Hashie::Mash

[zuk]

Requests with big payloads (in our case a large JSON object) are extremely slow. This is due to a bug in Hashie::Mash. See here: hashie/hashie#107

Once that pull request is pulled in, I'd recommend switching Grape's minimum requirement for hashie to >= 2.0.6 (assuming this gets released as 2.0.6).

In the meantime adding the git requirement to our Gemfile seems to have fixed the problem in grape:

gem 'hashie', :git => 'https://github.com/connectedbits/hashie.git'

[dblock]

What's the stack for where one hits this in Grape? Basically, how does one know whether this affects them badly or not?

[zuk]

I'll post some cases later, but I found that swapping in the patched
version of Hashie improved Grape performance across the board. It
becomes really noticeable when you're dealing with big JSON payloads. I had
one request that handled a very large JSON object (couple hundred kb), and
it took about 5 minutes to process. With the patched Hashie it now takes about 10 seconds.

[dblock]

Fyi, I have a branch with the fix and tests, https://github.com/dblock/hashie/tree/convert-value-performance-fix.

[dblock]

Closed via a77ac5b.