Bear Den Designs - The Decider's Musings

Fair Balancing for nginx

Thu, 28 Jan 2010 11:59:41 -0600

If you have a busy server running multiple mongrels you probably have noticed how nginx will sometimes queue requests onto already busy mongrels while some mongrels are completely idle.

There is now a fair balancer plugin for nginx that makes it fair rather than round robin. It’s easy to install. Grab the the plugin here and grab the latest stable release of nginx (I’m using 0.7.6) from here

Follow the directions on github:

Installation:

You’ll need to re-compile Nginx from source to include this module.
Modify your compile of Nginx by adding the following directive
(modified to suit your path of course):

./configure —with-http_ssl_module —add-module=/absolute/path/to/nginx-upstream-fair make make install

Usage:

Change your Nginx config file’s upstream block to include the ‘fair’ directive:

upstream mongrel { fair; server 127.0.0.1:5000; server 127.0.0.1:5001; server 127.0.0.1:5002; }

Caution

One issue I ran into was having to change my nginx config files that contained false to off. For example:

proxy_redirect false;

now reads

proxy_redirect off;

De Morgan, Ruby

Thu, 21 Jan 2010 12:46:23 -0600

#De Morgan the Ruby way

[true,false].each do |p|
  [true,false].each do |q|
    puts "p=#{p} q=#{q}"
    if !(p or q) == (!p and !q)
      puts "De Morgan Rules! !(p or q) == (!p and !q)"
    else
      puts "De Morgan is a Liar!"
    end

    # if find yourself writing
    if !p and !q
      print "-"
      # you could be writing 
      unless p or q
        puts "if !p and !q equivalent to unless p or q"
      end
    end


    if !(p and q) == (!p or !q)
      puts "De Morgan Rules! !(p and q) == (!p or !q)"
    else
      puts "De Morgan is a Liar!"
    end

    # if find yourself writing
    if !p or !q
      print "-"
      # you could be writing 
      unless p and q
        puts "if !p or !q equivalent to unless p and q"
      end
    end

  end
end

Run individual shoulda tests

Thu, 29 Oct 2009 18:17:16 -0500

When you run tests of just one model or controller you usually do something like:

ruby test/unit/evaluation_test.rb

If you want to target just one test you can use the -n option

ruby test/unit/evaluation_test.rb -n test_return_pending_evaluatees_from_composite_group

For shoulda users if you want to target just one test the -n option can also take regular expressions.

ruby test/unit/evaluation_test.rb -v -n "/have many/"

The -v lists the test name before every test, aka verbose mode.

Please Spam This Post

Tue, 15 Sep 2009 20:27:50 -0500

Just updated the code to detect the spamming bastards. Let’s see if it works.

Pretty Local Rdoc

Mon, 06 Apr 2009 12:14:30 -0500

From the RubyInside site a couple of gems to make your local rdocs look and behave nicer.

To reap the benefits:

sudo gem install mislav-hanna sudo gem install manalang-bdoc sudo hanna —gems bdoc

Protect Staging Server with Password

Sat, 07 Mar 2009 13:20:50 -0600

When developing a new application and releasing often you may want to protect the site from prying eyes. A simple way to do this when using the nginx web server is to use basic http authentication.

I prefer to do this in the nginx config file so it doesn’t impact local development.

You’ll need to create a password file using htpasswd command line utility. This file should be relative to the install directory of nginx. The default install would place this file in /usr/local/nginx

sudo htpasswd -cb /usr/local/this_hosts_password_file username password

Next, you need to tell nginx to use basic auth for any access to this (virtual) host. I place the 2 relevant lines in the server portion of the config file

server { listen 80;

…
auth_basic “Login to see this alpha site.”;
auth_basic_user_file this_hosts_password_file;
…
}

A login will now be presented for any entry into the site.

Row Restaurant Does Vegetarian!

Sat, 07 Mar 2009 13:04:56 -0600

Great Vegetarian Meal at the Row Restaurant

Please see my huge disclaimer at the bottom

The Row Restaurant has been Jacksonville’s Magazines top 25 restaurants for 6 years straight. I live very close and head to the pub every now and then since they have delicious Rogue Juniper Pale Ale on tap. There’s also some excellent vegetarian appetizers. The artichoke dip comes to mind.

Even though there is no vegetarian options on the menu Chef Eric will whip up some stuffed grilled portabello’s or an extremely rich freshly prepared basil pesto pasta dish with fresh vegetables from the farmer’s market.

One night while I was there I had heard another table raving over his Chicken Marsala. Well, I don’t eat chicken but I had an idea. I asked Chef Eric if I could bring in a fake chicken patty and asked if he could prepare the dish completely vegetarian. He was up for the challenge! I ran home and grabbed some Quorn patties.

In about 15 minutes Chef Eric presented a wonderful meal for me and wife complete with fresh French green beans sauteed in a light butter sauce and roasted potatoes lightly spiced. The marsala wine gave a sweet hint while the capers rounded it out with a salty finish. We finished off with a special Chocolate cake dessert. The chicken marsala was fabulous.

I asked Chef Eric if he would be willing to do this for others and he gave an enthusiastic YES.

One thing to note, if you want to dine on Thursday, Friday or Saturday reservations are highly recommended.

Huge disclaimer
- My family owns and runs the The Riverdale Inn and The Row Restaurant
- My brother Eric is the Executive Chef
- I’m vegetarian and rarely eat there but love my brother’s cooking.

Best Vegetarian Restaurant in Jacksonville FL

Thu, 19 Feb 2009 17:42:13 -0600

The new Whole Foods Supermarket is probably the best all around vegetarian restaurant in Jacksonville. While visiting there on last Saturday they had 6 vegetarian main entrees. The selection ranged from Asian, kung pow tofu to Bar-B-Q Seitan.

The hot bar was very fresh and was constantly being monitored by several chefs and staff. There was traditional sides like mashed potatoes, sweet potatoes, macaroni and cheese….you name it.

In addition, they have a gelato bar, coffee/expresso, brick hearth pizza oven (slices available!) and a dessert bar.

The food is all $7.99 per pound and there is indoor and outdoor seating with free WI-FI.

Rotating Rails Logs via logrotate

Tue, 17 Feb 2009 23:12:12 -0600

No need to repeat the excellent article NullisLove

If you are doing this on a ubuntu or debian based system make sure that logrotate is actually installed. It’s easy to be fooled since apache and mysql install rotate scripts in /etc/logrotate.d

To install:

sudo apt-get install logrotate

Add your new config file to: /etc/logrotate.d

/home/my_server/www/shared/log/*.log { daily missingok rotate 7 compress delaycompress notifempty copytruncate }

Test:

sudo logrotate -d /etc/logrotate.c/my_servers_rotate_script

Force a rotate:

sudo logrotate -f /etc/logrotate.c/my_servers_rotate_script

Sometimes the easy things can just be-fuddle you!

Awesome Nested Set Revealed!

Mon, 16 Feb 2009 15:06:37 -0600

Ok, there’s nothing new with nested sets in rails but I crawled through the Awsome Nested Set Code from CollectiveIdea on GitHub code and made a quick and dirty cheat sheet. Here you go.

Awesome Nested Set Cheat Sheet:

Basic Usage

Create a root node:

my_root = Category.create! :name => ‘root’

Put a new thing inside this root node:

my_new_thing = Category.create! :name => ‘Chair’ my_new_thing.move_to_child_of my_root

Put a “new” new thing inside this “new_thing” node:

my_2nd_new_thing = Category.create! :name => ‘Chair’ my_2nd_new_thing.move_to_child_of my_new_thing

Now you should have something that resembles this:

+ root |_____ my_new_thing |_____________ my_2nd_new_thing

Gratuitous picture of my dog Ella.

Accessing the data:

Class methods:

Category.root – returns the first root node
Category.roots – returns all root nodes

Instance methods:

my_cat.root? – true if this is a root node
my_cat.leaf? – true if this is a leaf node. It has no children.
my_cat.leaves – returns array of all nodes without children.
my_cat.child? – true if this is a child node. It has a parent.
my_cat.root – root for this node.
my_cat.parent – returns the immediate parent
my_cat.self_and_ancestors – returns array of all parents and self
my_cat.ancestors – returns array of all parents. Not including self.
my_cat.self_and_siblings – returns array of brothers and sisters and self. All at that level.
my_cat.siblings – returns array of brothers and sisters. Not including self.
my_cat.level – returns the level of this object in the tree. root = 0
my_cat.self_and_descendants – returns array of all children and self
my_cat.descendants – returns array of all children. Not including self.
my_cat.children – returns array of immediate children. Just those in the next level.
my_cat.is_descendent_of?(obj) – returns true if self is nested under obj
my_cat.is_or_is_descendent_of?(obj) – returns true if self is nested under obj or self is obj
my_cat.is_ancestor_of?(obj) – returns true if nested by any obj
my_cat.is_or_is_ancestor_of?(obj) – returns true if nested by any obj or self is obj