Rubynaut

DON'T USE "DISABLE WITH TEXT" OPTION WITH YOUR JQUERY AJAX BINDING

stephane — Mon, 10 Aug 2009 09:22:00 +0200

I ve just spent 5 hours to understand what was going wrong with my ajaxy form. I use jquery on rails and ajaxForm plugin, I have some form already working good and tried to a new one.

But this time it doesnt work, I dont understand why my form send twice the request, first with ajax header and second time with html request. I even tried to write raw javascrit, livequery and so on. Nothing make it works. Finally I want to check a little thing I add on the form: ‘disable with text’ option. I disabled it and miracle it works now.

I ve lost 5 hour of my time for this little cosmetic tool that s mess up ajax binding.

Then my advice: DON’T USE “DISABLE WITH TEXT” OPTION WITH YOUR JQUERY AJAX BINDING.

How to access multiple databases with rails

stephane — Sat, 31 May 2008 19:08:00 +0200

I know it exists other information about this, but I want to summarize here the practise I use in several project now. It takes 4 steps:

configure your database.yml
create an abstract class for connection
create new models within a module
interact the 2 databases

1. Configure your database.yml

This is the same as you create production or development connection, just give it a specific name:

other_database_connection:
    adapter: postgresql
    encoding: utf8
    database: database_name
    username: user
    password: password
    host: localhost

2. Create an abstract class for connection

Then create an abstract class you will inheritate by your new classes:

class External < ActiveRecord::Base
  self.abstract_class = true
  establish_connection :other_database_connection
end

3. Create new models within a module

To make it easier to use and cleaner, create a subfolder OtherDatabase and then create in this folder your new classes (for each table you need) as following:

class OtherDatabase::NewClass1 < External
end

4. How to interact the 2 databases

Once you have created your new classes, you can simply access it using the module prefix:

new_object = OtherDatabase::NewClass1.new
.
result = OtherDatabase::NewClass1.find(:all)

Conclusion

That’s all, submodule is not really necessary but keeps your model folder cleaner. Any suggestion to improve this practise ?

Rails: find controller for a path

stephane — Sun, 06 Apr 2008 14:20:00 +0200

Huh, seems simple to do :p, but I’ve been seeking for a while to find the answer and dig into rails code to find a simple method to retrieve the controller of a given path (could be useful to build a navigation). There it is:

ActionController::Routing::Routes.recognize_path(path)[:controller]

Ebb, even faster than Thin

stephane — Tue, 04 Mar 2008 22:02:00 +0100

Ebb is new server to put in front of a rackable ruby application.

Have a look to the Ebb website to get some comparison with other app servers.

sudo gem install ebb

What I needed to do before on Mac OS X (leopard with MacPorts):

sudo port install glib2

Git: Easy way to setup a private remote repository

stephane — Tue, 04 Mar 2008 20:41:00 +0100

Git is different from svn and create a private repository on a remote server too. No need of gitosis or git-daemon for this.

I start from an existing project and a server I already access to with ssh key.

First, initialize git in your project:

git init
git add .
git commit -m 'initial import'

[update]

~~Then create a git copy of your project into a git archive my_project_folder.git.~~

~~git clone—bare my_project_folder my_project_folder.git~~

Copy ~~this archive~~ the .git folder to your remote server:

scp -rp .git user@server://path/to/repositories/my_project_folder.git

Add this new repository in the config of your local project:

git remote add my_remote_repo ssh://server/path/to/repositories/my_project_folder.git

You’re done. After a change you can commit and then push your change to the remote repo:

git commit -m "message for change log"
git push my_remote_repo

Use your own parameters for:

my_project_folder with the folder of your project
path/to/repositories with the path to your repository on the remote server
my_project_repo with the name you want for the remote repository, usually origin

If you need a public repository, have look to gitosis or git-daemon. Best is Github.

Model inheritance with Merb

stephane — Thu, 21 Feb 2008 22:16:00 +0100

from help on irc#merb

I had recurrent issue about inherit a model class from another one in Merb, using ActiveRecord or DataMapper. As it’s ‘magicly’ done on Rails I though the same way in Merb, but the last one load model class in alpha order. then what you have to do is to load the first class with a require:

in your first file:

class Page < ActiveRecord::Base
end

then in second add the require:

require 'page'

class ActivePage < Page
end

Simply using ruby…

Most used front end: poll results

stephane — Wed, 20 Feb 2008 13:35:00 +0100

For severals month now I put a poll about which front end people use for their website. Even if it s not a reference with only 85 votes I would like to publsih some result. Of course as the content of this website is ruby oriented, then the results will be also.

First it started with most of votes for apache. At the end Apache it’s still the first:

47%: apache
40%: nginx
7% : lighttpd
5% : others

The result for nginx is over general real stats but for the trend is here and nginx is more and more the choice for a ruby stack as I did present in my last post

Scaling a Rails app (Part 3 of 3)

stephane — Tue, 19 Feb 2008 18:05:00 +0100

This the third and last part for a summary about solutions to help better computing of your rails app

1st part.
2nd part.

Some home made benchmarks

NB: Following benchmarks have been made to a quick look study and not for a proof of concept.

The test machine (dedibox, ubuntu 6.10) is 1 core cpu @2Ghz – 1024 Mo memory. In each case the http server uses 10 processes on a real world application (not just ‘hello world!’). Sending 500 rq with 1 or 10 concurrency req:

conc. req.	1	10
apache
mongrel	39.4s – 12.7 r/s	21.9s – 22.8 r/s
thin	37.6s – 13.3 r/s	17.7s – 28,15 r/s
nginx
mongrel	39.2s – 12.8 r/s	22.2s – 22.5 r/s
thin 0.5.4	39.8s – 12.6 r/s	17.7s – 28.15 r/s
thin 0.6.1 socket x2	37.6s – 13.3 r/s	17.8s – 28.1 r/s

Since last time, Rails world has a new nice app server: thin. Replacement of mongrel, based on rack interface, it’s also recently added a unix socket connector where usually we use IP connector. For better performance, avoid longest stuff as scripts (google analytics). Other scripts/images/css are keys in http performances also, usage of assets in recommended.

As we can see in equivalent configuration there is no major difference for http server. Thin seems to be definitly faster than mongrel when you need to server more than 1 request at a time. And of course on a 1 core cpu, having more than one app server doesnt make the content served really faster.

Memory usage

Mongrel (48 Mo) -> Thin (40 Mo) less 15%

Apache (10 Mo) -> Nginx (1.4 Mo) less 85%

Finally I decided to move to a nginx / thin on socket configuration because of the memory usage and the fair performances. I even moved my PHP stuff with an fcgi connector.

Other ideas of tests: Varnish, Nginx and memcached. Maybe next time :)

[update]

Please find a good benchmark about nginx vs apache on Joe’s blog

Overall conclusion

I think when we need to compare two framework, about which one is faster, we should keep in mind all these levels of optimisation to scale an application, and then the raw performance is a secondary issue.

Radiant to Merb

stephane — Sun, 17 Feb 2008 20:33:00 +0100

Merb is a (future) great framework. Radiant is good CMS. And they have so much in common. I’m curious about porting Radiant to Merb then I started the challenge. For people interested in the same challenge, I set up a repository. Then please feel free to participate.

[update]

I got invited on github then I cloned the git repository to http://github.com/sbusso/merb_radiant/tree/master

Action plan:

Merb is a framework equivalent to Action Pack. It can use Active Record. For generator we can use Rubigen, it s an extract of RailsGenerator.

For this we will use:

Radiant trunk r742
Merb (core and more) 0.9.0
Merb helpers 0.9.0
Merb ActiveRecord 0.9.0
ActiveRecord 2.0.2
Rubigen 1.2.0

The repository tree was build with:

Hoe (modified) generated skeleton
Merb application
Radiant source

1. Move Radiant base:

use plugins as gem:
- radius 0.5.1
- highline 1.4.0
- rubypants 0.2.0
use other plugins as ruby libraries:
- redcloth
- bluecloth
using active record: nothing to do
radius and other ruby libs: nothing to do
replace RailsGenerator with Rubigen (Radiant bin)
work on initializer
desactivate extension dependencies (first step we move only the base)
manage Controller and libraries using controllers
check routes management
work on views to replace Rails specific code

2. Replace extension system with gems:

first, activate gem with only code features
second, deal with extension providing assets

Merb 0.9.0 - only for developer

stephane — Thu, 14 Feb 2008 22:02:00 +0100

Following the next version of Merb, I’m a bit surprised by the way this new version came out:

Merb 0.9.0

Help of developers is needed for going on 1.0, then install it and try it.

Included :

merb-core
merb-action-args
merb-assets
merb-gen
merb-haml
merb-mailer
merb-parts
merb-more
merb

then

merb-gen myapp

Install ruby memcached on MacOSX

stephane — Tue, 12 Feb 2008 22:13:00 +0100

Classical way, download following archives and compile it in the order. Xcode has to be installed.

tar xzf *.tar.gz
cd 
./configure
make 
sudo make install

lib need for server: lib event. download
the server: memcached. download
the client lib written in c: libmemcached. download

the ruby binding:

sudo gem install memcached

or with leopard:

sudo env ARCHFLAGS="-arch i386" gem install memcached

Scrubyt on Rails

stephane — Tue, 16 Oct 2007 13:11:00 +0200

If like me you have an error after installing scrubyt 0.3.4 (in console and launching mongrel):

can't activate RubyInline (= 3.6.3), already activated RubyInline-3.6.4]

I spent a lot of time to find the solution, and so easy solution … anyway could be useful for people googling about this. You just need to unsinstall the lastest installed version of RubyInline:

sudo gem uninstall RubyInline -v 3.6.4

Everything should be fine with this, even Scrubyt requiring version 3.6.3.

Scaling a Rails app (Part 2 of 3)

stephane — Sun, 14 Oct 2007 14:18:00 +0200

This the second part for a summary about solutions to help better computing of your rails app (1st part).

Application

To help your application to focus on replying fast to user, you can use a distributed queueing to give the job to other processes:

And second thing, you can cache things you don’t need to compute for each request, this can incredibly increase the response of your server, but need to modify your code and it s recommend for very big sites:

Back end

DB

For your database you can find some sql proxy, but I haven’t tried it yet. You have also the way to replicate your databse and serve data from several servers.

sql relay
use jruby with a jdbc pool connection and caching

Important things you have to check about your databse is if you have the right indexed fields. You should find some tools on mysql helping you to find where indexes missing. Check about cache too.

A last way is to serialize some of your data in a single object.

Mysql

Otherwise you can configure your mysql with some optimized configuration (mysql.ini):

skip-name-resolve
query_cache_size = 52428800;
query_cache_type = 1

And in your ActiveRecord object you can use the * parameter.

Filesystem

Optimizing the filesystem, in other sense than choose a good OS, can been done with not overloading the management of files by using some *rules:

max 10K files / subdir
16 top level / 256 sub / 10K per sub dir
use a hasher to manage files

OS

As we have seen, file and memory management are keys of good performances. And these are managed by OS. The two best OSs mentionned are

Sunsolaris
FreeBSD (can be use for a all in one stack), avoid the version 5

And upcoming, last part of this article, some home made benchmarks for my own purpose.

Scaling a Rails app (Part 1 of 3)

stephane — Wed, 10 Oct 2007 20:32:53 +0200

One of the most interesting topic in the RailsConf was Scaling your Rails app. There are 2 ways of doing it:

adapt your code
adapt your servers

But the second one will not help to make your code faster. It will just help to give maximum resources to compute it right.

Summaries from the conference (sorry for the so few litterature it will be only a summarize):

Some theories

These theories are for big websites with millions of hits every month. This can involve thousand of servers, different location, ... BTW some tips can be use to help smaller configurations.

The 7 layers to be considered, a la OSI.

DNS
frontend
proxy
application server
application
backend (Db , filesystem)
OS

DNS

Nice website to check your DNS configuration: dnsstuff.com Good tool to optimize your DNS: speed, dispatching, and so on…: powerdns

DNS can be quite fast to address the right server from a request, scripts allow to manage complex configurations. The tip is to use 1 DNS entry per 1 controller, then managing part of the routing.

Frontend and Proxy

Load balancing is about dispatching requests taking in account the charge of each cluster.

Load balancers: Varnish HAProxy

Both look promising and HAProxy seems to be more and more popular.

Front end with load balancer: Nginx : fast, low memory usage, http server with load balancing, easy configuration, very good in front of mongrel cluster. Apache 2.2 + mod_proxy_balancer, you can find how to setup it in previous post: apapche, mongrel cluster, rails on a load balancer

Application server

mongrel server: enough for a personnal server gem install mongrel mongrel_rails start (more information)
mongrel_cluster: useful to scale up your configuration, need at least a multi-processor or multi server environnment. gem install mongrel_cluster mongrel_rails cluster::configure … mongrel_rails cluster::start
Evented Mongrel (swiftiply): it’s a mongrel based an event triggering
jruby / glassfish: the technology java comes with some good environment to speed up part of your application like connection to database (jdbc, pool connection)

to be continued (application, backend, OS, and some home benchmark)

Nginx and Mongrel cluster on debian

stephane — Sun, 23 Sep 2007 18:24:00 +0200

Nginx is a ‘small’ efficient http, load balancer server. More and more popular in Rails community, it’s a good front end for mongrel clusters. It’s seems to be a good replacement for apache, at least for the memory usage (on my test: 1 process use 1.3M against the more than 9M taken by 1 apache process). Benchmark on one single server are quite similar.

The process has been tested on debian 4.0r1 and should work on Ubuntu.

Installation

apt-get install nginx

or, if you want an up to date product:

1/ Prepare your system

apt-get install zlib1g-dev libgcrypt11-dev libpcre3-dev libssl-dev

2/ Download source

tar xzf nginx-0.6.12.tar.gz
cd nginx-0.6.12

3/ Compile it

./configure --pid-path=/usr/local/nginx/logs/nginx.pid \
    --sbin-path=/usr/local/sbin/nginx \
    --with-md5=/usr/lib \
    --with-sha1=/usr/lib \
    --with-http_ssl_module \
    --with-http_dav_module --prefix=/usr \
    --conf-path=/etc/nginx/nginx.conf \
    --pid-path=/var/run/nginx.pid \
    --lock-path=/var/run/nginx.lock \
    --error-log-path=/var/log/nginx/error.log \
    --http-log-path=/var/log/nginx/access.log 

make

sudo make install

Configuration

The following configuration is for 1 nginx server with load balancing 3 mongrel in cluster:

1/ Mongrel cluster configuration

gem install mongrel_cluster -y

cd /var/www/my-app-path/current/

configures 3 mongrel in cluster, in production mode, starting at port 5000 and listening on localhost

sudo mongrel_rails cluster::configure -e production \
    -p 5000 -N 3 -c /var/www/my-app-path/current/ -a 127.0.0.1 \
    --user www-data

mongrel_rails cluster::start

2/ Nginx

nano /etc/nginx.conf

Use the nginx.conf file from brainspl.at website, change the 2 or 4 (if you use ssl) references to the path of your application (/var/www/my-app-path/current/)

/etc/init.d/nginx start

All these information come from many website (thanks to all), I put them together for my own usage, hope it’s helpfull.