Rack-Mini-profiler – The Secret Weapon of Ruby and Rails Speed | Hacker News Reader

Rack-Mini-profiler – The Secret Weapon of Ruby and Rails Speed

nateberkopec.com

Another tool that helped us out tremendously was http://stackshare.io/skylight.

It allowed us to quickly determine what pages were slowest and why, but also what pages were being hit the most by users. Sorting by 'agony' means: "This page is a combination of being hit the most, and the slowest. Take care of it pronto."

Amazingly, we started knocking out 'agony' problem areas, and our site is super quick now with minimal effort.

Here's an example of what their dashboard looks like:

http://i.imgur.com/b4zhh6Q.png

I've tried out Skylight, but if you already have New Relic, didn't see anything new.

NewRelic's UX is ABYSMAL. It has not once given us useful insight into anything.

Thanks heaps Nate for the writeup!

Some other resources on rack-mini-profiler are:

https://samsaffron.com/archive/2013/03/19/flame-graphs-in-ru...

https://samsaffron.com/archive/2012/07/12/miniprofiler-ruby-...

Some history: https://samsaffron.com/archive/2011/06/09/+Profiling+your+we...

My talk, measuring Ruby https://www.youtube.com/watch?v=LWyEWUD-ztQ

And Off the Rails https://www.youtube.com/watch?v=aP5NNkzb4og

The development mode of New Relic (https://docs.newrelic.com/docs/agents/ruby-agent/developer-m...) is another good tool to find out about response times of your controller actions and the number of SQL queries. I'm pretty sure you can use it even if you're not on a paying plan for New Relic. We switched to this after we weren't been able to get rack-mini-profiler to work in a Rails app for a single-page app as the Rails app only returns JSON and doesn't render templates.

> If you're forcing SSL in production, you're going to want to turn that off for now.

Great article, but there's no further mention about SSL. Specifically, why should I turn it off in the first place for this gem, and when/how can I turn it back on? Is there some special step(s) needed to do so, and what are they?

It's because the article takes you through running your app in production environment locally on your machine. To do that with ssl you'd need to get that setup locally as well, so I think the author just wanted to avoid dealing with that.

Correct - that's exactly what I meant. Don't turn your SSL off on your production server just to run this gem - that'd be silly!

> production environment locally on your machine

Oxymoron!

I've never used it but there is also something called Rails Panel someone might find useful: https://github.com/dejan/rails_panel

Hasn't Peek (https://github.com/peek/peek) sorta replaced Rack-Mini-Profiler?

What's better about Peek?

> To see a full list of rack-mini-profiler's features and info on how to trigger them, add ?pp=help to the end of any URL

Wait... in production? Anyone can do this?

My guess is that this blurb is relevant:

> rack-mini-profiler runs in the development environment by default in Rails apps. We're going to enable it in production, and hide it behind a URL parameter. You can also do things like make it visible only to admin users, etc.

No. RMP is disabled by default in production and must be enabled manually with `Rack::MiniProfiler.authorize_request` - so you can set it up behind a URL parameter, or something more secure like your already-built admin system or whatever.

Are there tools like this for other languages? For asp.net there is Glimpse and the Mini profiler. What about Java, php, node, python?

For Meteor (Javascript) there's Kadira. http://stackshare.io/kadira

For PHP there is PHP Debug Bar - http://phpdebugbar.com/, although if you're using a framework you'd want to find the fork with the bindings. I'm using the one for Laravel and it's pretty good https://github.com/barryvdh/laravel-debugbar

There's also xdebug, which can give a lot of detailed information. And then there's New Relic for PHP.

There are similar MiniProfilers for Go, Node, and Dotnet: https://github.com/MiniProfiler

Good post but please, please, please don't enable this in productiont. What an extremely wonderful way to DDoS any Rails app (as if it weren't easy enough already). If you need production like characteristics for accuracy of profiling then set up another environment that is production-like (Rails settings, replicated database, infrastructure etc.) and run it there.

You can put `rack-mini-profiler` behind authentication. It is not enabled by default in production. I believe I mentioned this in the article, if not, it's in the README.

I would try and word it more carefully. The phrase "in production" has serious meaning. I think that's what startled myself (and it seems like some others, too).

Although your take away may have been that everyone should enable it in production. I think every developer should use common sense and practical knowledge when implementing a feature in their application. If you want to use it you should know that having this available for all users is not a great idea, and use it accordingly.

You would be surprised by the lack of common sense in the software community. Maybe even more so in Ruby/Rails. As an example, there are a lot of people running WEBrick in production.

I agree with rubiquity - the article as written strongly suggests that users enable it in production. I'd amend it to be far clearer about what you mean. Directly from the second paragraph:

> The best part - rack-mini-profiler is designed to be run in production. Yeah!

Then later:

> rack-mini-profiler is designed to be used in production.

MiniProfiler was originally developed at StackExchange for production profiling.

It gave admins a clear picture of what is going on, all the time, and transformed the way we reasoned about performance.

rack-mini-profiler is a port, I use it in development and still predominantly in production!

The key is that ONLY and ONLY admins get access to the features, and we only do profiling for admins. To achieve this nothing is measured unless a request is explicitly authorized.

Very odd to hear this DDoS concern.

The secret to rails speed is not using rails at all.

Yeah, better to use assembly and spend a week to implement trivial features :)

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