Both GitHub and 37 Signals use nginx + unicorn.

https://github.com/blog/517-unicorn

[Passenger](http://www.modrails.com/) running on Apache. Easy to set up, low memory usage, and well supported.

[Passenger][1] is becoming the norm. It has more configuration options and [is faster][2].


  [1]: http://www.modrails.com/
  [2]: http://izumi.plan99.net/blog/index.php/2008/03/31/benchmark-passenger-mod_rails-vs-mongrel-vs-thin/

Additionally, for something very quick/easy on dev, try http://pow.cx/

In python, a module doesn&#39;t *have* to have a main function, but it is common practice to use the following idiom:

    def my_main_function():
        ... # some code

    if __name__==&quot;__main__&quot;:  # program&#39;s entry point
        my_main_function()

I know Ruby doesn&#39;t *have* to have a `main` method either, but is there some sort of best practice I should follow?  Should I name my method `main` or something?

The [Wikipedia page about main methods][1] doesn&#39;t really help me.

----------
As a side-note, I have also seen the following idiom in python:

    def my_main_function(args=[]):
        ... # some code

    if __name__==&quot;__main__&quot;:  # program&#39;s entry point
        import sys
        sys.exit(my_main_function(sys.argv))

  [1]: http://en.wikipedia.org/wiki/Main_function_(programming)#Ruby

Should I define a main method in my ruby scripts?

Does somebody know how &quot;modular&quot; is Django? Can I use just the ORM part, to get classes that map to DB tables and know how to read/write from these tables?

If not, what would you recommend as &quot;the Python equivalent of Hibernate&quot;?

Using only the DB part of Django

What is the best web server for ruby on rails application? Why?

What is the best web server for Ruby on Rails application?

<p>What is the best web server for ruby on rails application? Why?</p>


The will_paginate gem is broken on my version of Oracle. The default `paginate_by_sql` method in the WillPaginate module is inserting an extra &#39;AS&#39; into a query and causing it to fail.

The code itself is easily fixed, but I&#39;m not sure of the best way to get Rails to pick up my change.

I don&#39;t want to change the code in the gem itself, as that will leave my code broken on other machines.

I tried creating an lib/test.rb file containing:

    module WillPaginate
      def paginate_by_sql
        (my code goes here)
      end
    end

and requiring it from environment.rb, but it&#39;s not picking up my changes.
I also tried requiring it from controllers/application.rb, but again, not picking up my changes.

Temporarily, I got it to work by overriding the method within the specific model itself, but this is a bit of a hack, and means I can&#39;t use it on any of the other models in this project.

I&#39;m sure there&#39;s an easy way to do this, but I&#39;m not having any luck tracking it down using Google.

Overriding a module method from a gem in Rails

I&#39;m trying to optimize some of the database queries in my Rails app and I have several that have got me stumped.  They are all using an `IN` in the `WHERE` clause and are all doing full table scans even though an appropriate index appears to be in place.

For example:

    SELECT `user_metrics`.* FROM `user_metrics` WHERE (`user_metrics`.user_id IN (N,N,N,N,N,N,N,N,N,N,N,N))

performs a full table scan and `EXPLAIN` says:

    select_type: simple
    type: all
    extra: using where
    possible_keys: index_user_metrics_on_user_id  (which is an index on the user_id column)
    key: (none)
    key_length: (none)
    ref: (none)
    rows: 208

Are indexes not used when an `IN` statement is used or do I need to do something differently?  The queries here are being generated by Rails so I could revisit how my relationships are defined, but I thought I&#39;d start with potential fixes at the DB level first.

MySQL not using indexes with WHERE IN clause?

For *ad hoc* Rails tasks we have a few implementation alternatives, chief among which would seem to be:

    script/runner some_useful_thing

and:

    rake some:other_useful_thing

Which option should I prefer? If there&#39;s a clear favourite then when, if ever, should I consider using the other? If never, then why would you suppose it&#39;s still present in the framework without deprecation warnings?


I have a Rails task: should I use script/runner or rake?

I need to create one config option for my Rails application. It can be the same for all environments. I found that if I set it in `environment.rb`, it&#39;s available in my views, which is exactly what I want...

    environment.rb

    AUDIOCAST_URI_FORMAT = http://blablalba/blabbitybla/yadda

Works great.

However, I&#39;m a little uneasy. Is this a good way to do it? Is there a way that&#39;s more hip?

Best way to create custom config options for my Rails app?

I want to validate a date in my model in Ruby on Rails, however, the day, month and year values are already converted into an incorrect date by the time they reach my model.

For example, if I enter February 31st 2009 in my view, when I use `Model.new(params[:model])` in my controller, it converts it to &quot;March 3rd 2009&quot;, which my model then sees as a valid date, which it is, but it is incorrect.

I would like to be able to do this validation in my model. Is there any way that I can, or am I going about this completely wrong?

I found this &quot;[Date validation][1]&quot; that discusses the problem but it never was resolved.


  [1]: http://www.ruby-forum.com/topic/53191


How do I validate a date in rails?

What is the difference between application server and web server?

I am using Nginx in front of 10 mongrels.

When I make a request with size larger then 2900 I get back an:

&gt; error code 414: uri too large

Does anyone know the setting in the nginx configuration file which determines the allowed uri length ?

How to set the allowed url length for a nginx request (error code: 414, uri too large)

How do I test if [memcache][1] or [memcached][2] (for PHP) is installed on my Apache webserver?

&gt; **Memcache** is a caching daemon designed especially for
dynamic web applications to decrease database load by
storing objects in memory.


  [1]: http://pecl.php.net/package/memcache
  [2]: http://pecl.php.net/package/memcached

How to check if memcache or memcached is installed for PHP?

I&#39;ve developed some web-based applications till now using PHP, Python and Java. But some fundamental but very important questions are still beyond my knowledge, so I made this post to  get help and clarification from you guys.

Say I use some programming language as my backend language(PHP/Python/.Net/Java, etc), and I deploy my application with a web server(apache/lighttpd/nginx/IIS, etc). And suppose at time T, one of my page got 100 simultaneous requests from different users. So my questions are:

 1. How does my web server handle such 100 simultaneous requests? Will web server generate one process/thread for each request? (if yes, process or thread?)
 2. How does the interpreter of the backend language do? How will it handle the request and generate the proper html? Will the interpreter generate a process/thread for each request?(if yes, process or thread?) 
 3. If the interpreter will generate a process/thread for each request, how about these processes(threads)? Will they share some code space? Will they communicate with each other? How to handle the global variables in the backend codes? Or they are independent processes(threads)? How long is the duration of the process/thread? Will they be destroyed when the request is handled and the response is returned?
 4. Suppose the web server can only support 100 simultaneous requests, but now it got 1000 simultaneous requests. How does it handle such situation? Will it handle them like a queue and handle the request when the server is available? Or other approaches?
 5. I read some articles about Comet these days. And I found long connection may be a good way to handle the real-time multi-users usecase. So how about long connection? Is it a feature of some specific web servers or it is available for every web server? Long connection will require a long-existing interpreter process?

---

EDIT: 
Recently I read some articles about CGI and fastcgi, which makes me know the approach of fastcgi should be a typical approach to hanlde request.

&gt; the protocol multiplexes a single transport connection between several independent FastCGI requests. This supports applications that are able to process concurrent requests using event-driven or multi-threaded programming techniques.

Quoted from [fastcgi spec][1], which mentioned *connection* which can handle several requests, and can be implemented in mutli-threaded tech. I&#39;m wondering this *connection* can  be treated as *process* and it can generate several *threads* for each request. If this is true, I become **more** confused about how to handle the shared resource in each thread?

P.S thank Thomas for the advice of splitting the post to several posts, but I think the questions are related and it&#39;s better to group them together.

Thank S.Lott for your great answer, but some answers to each question are too brief or not covered at all. 

Thank everyone&#39;s answer, which makes me closer to the truth.

  [1]: http://www.fastcgi.com/devkit/doc/fcgi-spec.html &quot;fastcgi spec&quot;

Some fundamental but important questions about web development?

Is Tomcat a web server or an application server?

Content Type	Original Author	Original Content on Stackoverflow
Question	ecleel	View Question on Stackoverflow
Solution 1 - Ruby on-Rails	Sai Perchard	View Answer on Stackoverflow
Solution 2 - Ruby on-Rails	Luke	View Answer on Stackoverflow
Solution 3 - Ruby on-Rails	ryeguy	View Answer on Stackoverflow
Solution 4 - Ruby on-Rails	Sai Perchard	View Answer on Stackoverflow

What is the best web server for Ruby on Rails application?

Ruby on-Rails Problem Overview

Ruby on-Rails Solutions

Solution 1 - Ruby on-Rails

Solution 2 - Ruby on-Rails

Solution 3 - Ruby on-Rails

Solution 4 - Ruby on-Rails

Using only the DB part of Django

Should I define a main method in my ruby scripts?

Attributions