padrino-perf: watch out for problematic conditions in your app

[skade]

First of all: this is alpha, ugly and just a proof of concept that I wanted to show you.

This adds a small binary that allows to watch for know error conditions
and hook into certain aspects at startup time of a padrino application
to gather info.

Currently implemented is suite to detect json and yajl being loaded at the same time and tracking who loaded it.

Also, there is a horrible hack to ensure that load_paths added by padrino-perf are always in front of the $LOAD_PATH.

To try a sample run: add padrino-perf, json and yajl to your Gemfile. Run:

bundle exec padrino-perf -j -- padrino console

This is basically a nice alias for:

$ruby -r$PADRINO_PERF_SUITES/json -S padrino console

where $ruby is the ruby that called padrino-perf.

Then require json and yajl in any order:

.9.3-p125 :001 > require 'json'
 => true 
1.9.3-p125 :002 > require 'yajl'
Concurring json libraries have been loaded. This incurs an
unneccessary memory overhead at should be avoided. Consult the
following call stacks to see who loaded the offending libraries
and contact the authors if necessary:"

============
libname: json
============
/Users/skade/padrino/padrino-framework/padrino-framework/padrino-perf/lib/suites/json.rb:35:in `each'
/Users/skade/padrino/padrino-framework/padrino-framework/padrino-perf/lib/suites/json.rb:35:in `loaded_lib!'
/Users/skade/padrino/padrino-framework/padrino-framework/padrino-perf/lib/suites/yajl/yajl.rb:1:in `<top (required)>'
(irb):2:in `require'
(irb):2:in `irb_binding'
... cont
============
libname: yajl
============
/Users/skade/padrino/padrino-framework/padrino-framework/padrino-perf/lib/suites/json.rb:35:in `each'
/Users/skade/padrino/padrino-framework/padrino-framework/padrino-perf/lib/suites/json.rb:35:in `loaded_lib!'
/Users/skade/padrino/padrino-framework/padrino-framework/padrino-perf/lib/suites/yajl/yajl.rb:1:in `<top (required)>'
(irb):2:in `require'
(irb):2:in `irb_binding'

Its not really there yet and the implementation is very straigth-forward and generalized, but the technique can be used to built suites that track memory consumption during loading etc.

Its main strength is that it is not a library that you have to put in your Gemfile, but instead 'just' an extended Runtime.

[dariocravero]

I think it's a great start! Thanks @skade!.. I reckon that the community will be happy to see that we're looking after performance so much that we even have a performance analyser tool! :) In which direction do you see this growing? I've found a really good presentation that may help towards getting ideas of what we can include in a performance analyser too.

[skade]

At the moment, its just a fun thing to play around. Basically, its a proof of concept on how to inject certain tests into a padrino binary call.

[DAddYE]

👍

[dariocravero]

I'm merging this in. It's a great start point and will force us towards building/improving a performance tool in the long run :)

[dariocravero]

@minad's memory usage script in #1018 brought up an idea... Quick & dirty draft. Wouldn't it be a great fit in somewhere in the perf tools?

[basex]

I have used rack-mini-profiler in the past with padrino. It's quite useful and easy to use.
https://github.com/SamSaffron/MiniProfiler/tree/master/Ruby

[dariocravero]

@basex, I think that's a good idea. I haven't used it properly myself (just some particular tests) but I reckon we can easily integrate it. Feel free to push a PR anytime :)