Dusty Reagan

Cassandra is a highly scalable, eventually consistent, distributed, structured key-value store. It’s an alternative to SQL if you don’t need relational data structures. The best part is it’s super fast, and distributed. The worst part is there’s not much documentation or community, at least compared to MySQL. So, I’m doing my small part to contribute to Cassandra. Here’s how I installed Cassandra on Ubuntu 8.04.2 LTS (hardy), but these directions should work on pretty much any Linux distro.

1. First upgrade your software as is with the following two commands (just for good measure):

sudo apt-get update
sudo apt-get upgrade

2. Now, open up your Debian package sources list with Nano for editing using the following command:

sudo nano /etc/apt/sources.list

3. Next, add the following sources to your /etc/apt/sources.list file.

deb http://www.apache.org/dist/incubator/cassandra/debian unstable main
deb-src http://www.apache.org/dist/incubator/cassandra/debian unstable main

After you add these two lines, press cntrl+X to close Nano. It’ll ask “Save modified buffer?” Press Y. Press Enter when Nano asks “File Name to Write.”

4. Run the update to install Casandra with this command:

sudo apt-get update

5. ERROR! At this point you receive an error similar to this:

W: GPG error: http://www.apache.org unstable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY F758CE318D77295D

6. Use the following three commands to ignore the signature error, and continue installing:

NOTE: You must replace the key value ‘F758CE318D77295D’ with the key value you received in your error message.

gpg --keyserver wwwkeys.eu.pgp.net --recv-keys F758CE318D77295D
sudo apt-key add ~/.gnupg/pubring.gpg
sudo apt-get update

7. Install Cassandra:

sudo apt-get install cassandra

8. Next you need to change Cassandra’s default port number from 8080 to something else, because the 8080 port typically conflicts with SSH terminal connections. Use Nano to open up the Cassandra configuration file using the following command:

sudo nano /usr/share/cassandra/cassandra.in.sh

9. Then change the port number 8080 on the following line to 10036, and save the file:

-Dcom.sun.management.jmxremote.port=10036 \

10. Start Cassandra with the command:

/etc/init.d/cassandra start

Once you have Cassandra running, test it with Cassandra’s command line tool CLI. Use the example found on the Cassandra Wiki.

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On November 1st I shaved my face clean for a friendly bet amongst my friends on who could grow their mustache the longest before their significant other gave them ultimatum to shave it. As it turns out, our little bet coincided exactly the same day Movember started. What is Movember? Movember is an annual, month-long celebration of the moustache, highlighting men’s health issues – specifically prostate and testicular cancer. This of course is brilliant, and I couldn’t help but join the cause.

You can help fight against prostate and testicular cancer by becoming a sponsor of my mustache. “Ridiculous” you say? Ok, sponsoring a mustache is a little silly, but this Movember, the money raised in the U.S. will be split between the Prostate Cancer Foundation and the Lance Armstrong Foundation to fund research to find better treatments and a cure for prostate cancer, and there’s nothing silly about that.

DONATE HERE
The link so nice, some times you have to click it twice [to make it work].

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I’m writing a book for the popular “For Dummies” brand by Wiley, Twitter Application Development for Dummies, #TADD for short.

While doing research for the book I compiled a brief timeline of Twitter’s company history. I was about to remove it from my notes when I realized it was kind of interesting, and I might like to refer to it later. So, I’m throwing it up on the blog for you to enjoy.

• March 21, 2006 – 1st Tweet – http://en.wikipedia.org/wiki/Twitter#History
• July 2006 – Twitter.com goes public – http://en.wikipedia.org/wiki/Twitter#History
• Oct 2006 – Ev, Biz, others aquire Odeo & Twitter as Obvious Corp – http://en.wikipedia.org/wiki/Twitter#History
• February 19, 2007 – Odeo sold – http://en.wikipedia.org/wiki/Odeo
• March 2007 – SXSW hype fest - http://en.wikipedia.org/wiki/Twitter#History
• April 2007 – Twitter spun off into its own company – http://en.wikipedia.org/wiki/Twitter#History
• July 2007 – $5M Funding – http://www.crunchbase.com/company/twitter
• Aug 2008 – $15M Funding – http://www.crunchbase.com/company/twitter
• March 2009 – $35M Funding – http://www.crunchbase.com/company/twitter

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First upgrade your software as is.

>> sudo apt-get update

>> sudo apt-get upgrade

Then add the following to your /etc/apt/sources.list file.

>> sudo nano /etc/apt/sources.list

deb http://http.us.debian.org/debian stable all
deb http://security.debian.org/ stable/updates main contrib
deb http://packages.dotdeb.org/ stable all

Finally run the update to install PHP 5.2.9.

>> sudo apt-get update

>> sudo apt-get install php5-cli

>> sudo /etc/init.d/apache2 restart

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Here’s the scenario. You have a WordPress MU site with multiple blogs, but for whatever reason, you want every blog to have the same main navigation and pages. Your main site/blog hosts all of your pages. So how do you go about creating a WordPress MU Theme that will use the navigation and pages from your main site/blog accross all of your blogs? Well, I’m here to tell you how I did it.

The WordPress Codex has a function called ‘wp_list_pages.’ What I wanted to do is create a new function called ‘wp_list_main_pages.’ So I simply searched my WordPress install and copied the ‘get_pages’ and ‘wp_list_pages’ functions and pasted them into my theme’s ‘functions.php’ file. From here I made a few edits to these functions. To start with, I renamed them ‘wp_list_main_pages’ and ‘get_main_pages.’

Below is the final code I’m using to display the main navigation accross blogs. I made notes in bold to help. Hope this is helpful to you Googling coders.

// You can use this function instead of 'wp_list_pages' in your theme
function wp_list_main_pages($args = '') {
	$defaults = array(
		'depth' => 0, 'show_date' => '',
		'date_format' => get_option('date_format'),
		'child_of' => 0, 'exclude' => '',
		'title_li' => __('Pages'), 'echo' => 1,
		'authors' => '', 'sort_column' => 'menu_order, post_title'
	);

	$r = wp_parse_args( $args, $defaults );
	extract( $r, EXTR_SKIP );

	$output = '';
	$current_page = 0;

	// sanitize, mostly to keep spaces out
	$r['exclude'] = preg_replace('[^0-9,]', '', $r['exclude']);

	// Allow plugins to filter an array of excluded pages
	$r['exclude'] = implode(',', apply_filters('wp_list_pages_excludes', explode(',', $r['exclude'])));

	// Query pages.
	$r['hierarchical'] = 0;
	// Right here we call our new 'get_main_pages' function
	$pages = get_main_pages($r);

	if ( !empty($pages) ) {
		if ( $r['title_li'] )
			$output .= '<li class="pagenav">' . $r['title_li'] . '<ul>';

		global $wp_query;
		if ( is_page() || $wp_query->is_posts_page )
			$current_page = $wp_query->get_queried_object_id();
		$output .= walk_page_tree($pages, $r['depth'], $current_page, $r);

		if ( $r['title_li'] )
			$output .= '</ul></li>';
	}

	$output = apply_filters('wp_list_pages', $output);

	// This line is sloppy and needs improvement.
	// You have to remove the name of the blog your currently on from you global navigation.
	// I'm doing this the simplest but least scalable way here.
	$output = str_replace("pressroom/", "", $output);

	if ( $r['echo'] )
		echo $output;
	else
		return $output;
}

// This is essentially a private function
function &get_main_pages($args = '') {
	global $wpdb;

	// This is the magic line.
	// Now when the SQL runs to pull your navigation pages, it'll use your main blogs ID.
	$wpdb->set_blog_id(1);

	// Notice here I call the original get_pages function and return the results
	$pages = get_pages($args);
	return $pages;
}

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