The nicely integrated Server Density monitoring does a great job of informing you if a server is down, but it can’t do anything about it. So I’ve created a script that I run on an external server to check all of the servers are up (via HTTP) and reboot those that are not. It’s fairly simple, the process is as follows:

• Get a list of VMs from VPS.NET.
• For each VM, send a GET request to http://{hostname}.{domainname}/ and give it (by default) 5 seconds to respond.
• If the server does not respond, it will check if it is marked as “running” on VPS.NET – by default it will then assume that there is simply a routing issue.
• If it is not, it will check if the server is already in a power change state (i.e. startup, reboot).
• Finally, if neither of the above are true, it will send a power on request to VPS.NET.
• After all of that, it’ll (optionally) send you an email to let you know.

The code is below. You can also download it here. Let me know if you find it useful!

Notes:

• This script needs setting up as a cron job, on an off-site server / computer. I recommend running it every 5 minutes or so.
• I don’t use the VPS.NET API PHP classes because they seem to be out of date.
• This script *will* spam you to oblivion if there is a cloud issue and you set it up to email in all cases.

< ?php

//----
// Set up the monitoring script:
//----

define('MONITOR_MAIL_TO', '');     // Email address to send alerts to.
define('MONITOR_API_EMAIL', ''); // Email address associated with VPS.NET API account.
define('MONITOR_API_KEY', '');     // VPS.NET API key.
define('MONITOR_SEND_EMAILS', true);               // Whether or not to send emails if a server is flagged as down.
define('MONITOR_SEND_EMAILS_ON_NO_ACTION', true);  // Whether or not to send emails if no action is taken.
define('MONITOR_REBOOT_IF_RUNNING', true);         // If HTTP check fails, but VPS.NET says the server is up, reboot?
define('MONITOR_HTTP_TIMEOUT', 5);                 // Number of seconds to allow for a server response. 

//----
// Initialise API Class and get VMs:
//----
$api = new SimpleVpsApi();
$api->setApiEmail(MONITOR_API_EMAIL);
$api->setApiKey(MONITOR_API_KEY);
$vms = $api->getVMs();

//----
// Loop through all the VMs and check their status:
//----
$out     = '';
foreach($vms as $vm)
{
	$server = $vm['virtual_machine']['hostname'] . '.' . $vm['virtual_machine']['domain_name'];
	$id     = $vm['virtual_machine']['id'];

	$get = false;
	$get = @file_get_contents('http://'.$server.'/', false, stream_context_create(array('http' => array('timeout' => MONITOR_HTTP_TIMEOUT))));

	if(!$get)
	{
		$_out .= 'Server ' . $server . ' appears to be DOWN!'.PHP_EOL;

		$vm = $api->getVM($id);

		if($vm['power_action_pending'])
		{
			$_out .= '- VPS.NET is reporting that the server is rebooting already. Taking no action.'.PHP_EOL;

			if(!MONITOR_SEND_EMAILS_ON_NO_ACTION)
			{
				$_out = '';
			}
		}
		elseif($vm['running'] && !MONITOR_REBOOT_IF_RUNNING)
		{
			$_out .= '- VPS.NET is reporting the server as running. Taking no action.'.PHP_EOL;

			if(!MONITOR_SEND_EMAILS_ON_NO_ACTION)
			{
				$_out = '';
			}
		}
		elseif($vm['running'] && MONITOR_REBOOT_IF_RUNNING)
		{
			$api->rebootVM($id);
			$_out .= '- VPS.NET is reporting the server as running. Rebooting.'.PHP_EOL;
		}
		else
		{
			$api->bootVM($id);
			$_out .= '- Submitted an automated power on request to VPS.NET.'.PHP_EOL;
		}

		// If we've logged anything for this VM, append it to the log:
		if($_out)
		{
			if($out != '')
			{
				$out .= PHP_EOL;
			}

			$out .= $_out;
			$_out = '';
		}
	}
}

//----
// Emailing functionality, for notification of server downtime:
//----

$email = '
	

		Server Monitoring Notice

			
		


	
';

if($out != '' && MONITOR_SEND_EMAILS)
{
	$email = str_replace('', nl2br($out), $email);
	mail(MONITOR_MAIL_TO, 'Server Monitoring Notice', $email, 'Content-Type: text/html'."\r\n");
}

//----
// Custom class for interacting with the VPS.NET API:
//----

class SimpleVpsApi
{
	const TYPE_GET  = 1;
	const TYPE_POST = 2;

	protected $apiUrl   = 'api.vps.net/';
	protected $apiEmail = null;
	protected $apiKey   = null;

	/**
	* Set the email address to use in requests:
	*/
	public function setApiEmail($email)
	{
		$this->apiEmail = $email;
	}

	/**
	* Set the API key to use in requests:
	*/
	public function setApiKey($key)
	{
		$this->apiKey = $key;
	}

	/**
	* Get a list of all VMs:
	*/
	public function getVMs()
	{
		$vm = $this->sendApiRequest('virtual_machines', 'GET');

		if($vm)
		{
			return $vm;
		}
		else
		{
			return array();
		}
	}

	/**
	* Sends a request to VPS.NET to load details about a VM:
	*/
	public function getVM($id)
	{
		$vm = $this->sendApiRequest('virtual_machines/'.$id, 'GET');

		if($vm)
		{
			return $vm['virtual_machine'];
		}
		else
		{
			return null;
		}
	}

	/**
	* Sends a request to VPS.NET to reboot a VM:
	*/
	public function rebootVM($id)
	{
		return $this->sendApiRequest('virtual_machines/'.$id.'/reboot', 'POST');
	}

	/**
	* Sends a request to VPS.NET to boot a VM:
	*/
	public function bootVM($id)
	{
		return $this->sendApiRequest('virtual_machines/'.$id.'/power_on', 'POST');
	}

	/**
	* Send an API request to VPS.NET
	*/
	protected function sendApiRequest($uri, $type = 'GET')
	{
		if(!$this->apiEmail || !$this->apiKey)
		{
			throw new Exception('You must set an API key and email address first.');
		}

		$opts = array(
		  'http'=>array(
		    'method'  => $type,
		    'header'  => 'Accept: application/json' . "\r\n" .
		                 'Content-Type: application/json' . "\r\n" .
						 'Authorization: Basic ' . base64_encode($this->apiEmail.':'.$this->apiKey) . "\r\n",

			'timeout' => 3,
		  )
		);

		$url      = 'https://'.$this->apiUrl.$uri.'.api10json';
		$context  = stream_context_create($opts);
		$response = @file_get_contents($url, false, $context);
		return json_decode($response, true);
	}
}

So, with the release of Safari 5 and it’s new extensions system, I thought I’d knock together something that does the same thing for Safari. It uses exactly the same CSS-based method that the Google Chrome extension does.

Want the extension? Download it here. Let me know if you have any problems with it.

Well, the short answer is I’ve just been busy!

Media Wow

Since I started at Media Wow, I’ve been busy there with a few projects. The biggest of which, our first “proper” web site build, is nearing completion and we’re excited to be launching it next Thursday. It’s one we’ve built from the ground up using WordPress, a custom design, some neat integration and we’re going to be hosting it on our in-house hosting platform we’ve set up with VPS.NET.

As soon as that’s done, we’re starting on eight web site builds for our biggest client. Whilst they’re certainly not sexy brands, they’re going to be fun to build, and it’s going to be nice to bring some brand consistency to the group.

Invision Power Services

Outside of that, I’ve also officially joined the Invision Power Services team, to help out on a part time basis. A lot of you will know that I’ve been working with IPS on and off for several years, with everything ranging from support, to skin design, to SEO. I’m very excited to be helping them in a more official role, and have already been pretty busy. Some of what I have been doing includes:

Search Engine Optimisation

I started out a few months ago helping to improve the search-friendliness of the IP.Board product, and we made some huge improvements for version 3.1, which was released last week.

I’m also now helping with optimising the Invision Power Services company web site. We’re aiming initially and primarily to target the term “forum software” (shameless linking, I know) and it is going remarkably well. In less than two months we’ve gone from not ranking at all in the first 150 positions to, as of the time of this post, position fifteen! We’ve even had brief stints in position five. Obviously this is a work in progress, and we’d naturally love to see ourselves hit position one.

Mobile Skin

Rikki did a great job designing the first iteration of the mobile skin for IP.Board 3.1. It was a vast improvement from previous light skins used for this purpose, but we decided that we wanted to target modern smart phones and give them a truly mobile experience. So Josh set to work on a native iPhone application, and I started to build upon Rikki’s mobile skin.

We’ve made it feel like a more native app, by replacing most of the links with touch-friendly buttons, making entire rows clickable instead of just the links within them, adding a loading indicator to give the impression it’s not simply a web page. These simple things have been very well received by regular users, and when coupled with the iPhone application, it looks and feels great.

Affiliate Banners

I noticed some time ago that a lot of the people in the affiliate pilot program are either using text links, or banners they have designed themselves. We’d never offered affiliates an official set of graphics to use on their sites and as a result, I felt we were missing the mark. So, I set out to create some official ones and they seem to have been very well received.

Support

Whilst this is not part of my role, since the release of IP.Board 3.1, I’ve even been helping out with support whenever I can. The sheer number of queries has been phenomenal, but the support team have been doing a truly amazing job at keeping up!

Outside Work

Guess what? My car broke again! This time, however, it needs an entirely new engine. I went through quite a bit of stress with Evans Halshaw trying to arrange for this work to be done on warranty, but thanks once more go to Ian McCandlish at Pendragon PLC for ensuring that the full cost of a new engine (£2,800~) was covered by my warranty, even if that did mean voiding the warranty going forward.

I also bought a red Rover 220 SDI as a temporary replacement car, which lasted me a week before an oil leak brought it to its knees. That car is now stuck at work until I’m brave enough to try and move it home, or I call the RAC to collect it. I’m going to try and sell it for spares or something, otherwise it’ll be a scrap job. It’s a bit of a shame, because the car itself is in good shape, it just seems a bit pointless trying to repair it now.

So, much to Charles Warner’s amusement, I’m spending a huge amount of time on trains back and forth to Durham, Manchester, and today, Denbigh in Wales. I’m almost starting to enjoy it, as it gives me a chance to think about things, write blog posts, make banners, etc.

When I started looking at it, I realised that my own blog site not only ranks for a lot of curious terms, but it gets a reasonable number of impressions even when it ranks poorly (page 3+, for example.) Here are a couple to demonstrate:

1,300 impressions for my site on page 3+ for the term ‘blackpool tower’? What does that imply? I’d hazard a guess that it could be people seeking out a cheap rate for getting into the tower, a freebie perhaps… otherwise some people must be really desperate to read a lot about places they visit.

We’re hoping to use this new dataset give us a better insight into how changes to page titles and meta descriptions affect click through rate, with the ability to ensure that fluctuations in search volume are not the actual cuase. I’d be intrigued to know how other people are using this and whether they’re finding it useful.

The move over has been incredibly positive so far. I feel better about the company, the work is interesting and the people are great. I had my first client meeting this week and it went exceptionally well, we’re now starting to build their new web site, which I hope is going to be a vast improvement on their current one.

I’ve also been getting some things set up here for us as a company, including our new hosting environment, rebuilding the company site in WordPress, and a few other bits and bobs. The office itself and the area it’s in is pretty cool too, I’ve included a couple of pictures – one of the office building and one of my desk.

It’s an exciting time and I think I’m going to be busy for quite some time, but I’m feeling good about it and looking forward to the challenge.

The lead singer of the band was awesome, and his hair was quite immense. Though I can’t compare the gig to any others, if ever you want a fun gig with great music, definitely check out Motion City Soundtrack.

On Thursday I start my new job at Media Wow and it promises to be an exciting experience. The work is already lining up, I know what I am going to be doing on my first day, I’ve picked up and configured my shiny new Macbook Pro and I’m raring to go. I’ll make sure to write about my first day on Thursday evening.

If you’re interested and haven’t done already, check out the web site or follow Media Wow on Twitter. I’m sure I’ll be posting to both when I’ve settled in.

My alternator broke, completely, at 6AM one morning driving back from Durham. When I bought the car, I was told it came with breakdown cover which I thought was with the RAC, so I called them, to find they had no record of me or my car. Same result with the AA. So I had to sign up to the RAC at a cost of £130, who came out and got me to a local garage, Fred Henderson Ltd (who were great, by the way!) My car was repaired before lunch time, but it cost me a further £275. As I was assured by the Evans Halshaw salesman that the warranty allowed such claims, I dutifully collected a full invoice with a detailed description of the work done.

I then contacted Evans Halshaw and was told that these kind of claims are not allowed, but that they’d contact the warranty company to “see what they could do.” Some weeks later, I got a definitive “no” response. I requested contact details for the warranty company, but never received a response.

Last week, I got frustrated and sent an email to both the branch manager in Leeds, and to Trevor Finn, the Chief Executive of Pendragon PLC, the company that own Evans Halshaw. I received two very different responses.

The branch manager called me to say that the policies are in place for a reason and that I should have read my documentation properly. As I told him on the phone, that’s all well and good, but when you’re 90 miles away from your warranty documentation in a broken down car in -4 degree cold, at 6am, three hours before Evans Halshaw open, you can’t be expected to follow policies.

Luckily, I was also called by Ian McCandlish, Pendragon PLC’s Divisional Managing Director of Group Finance and Insurance – the man in charge of the warranty division. Ian took a far more sensible and customer friendly approach to dealing with my complaint. Firstly, he read my email – which I’m not convinced the branch manager really did. Secondly, he set the policies aside and dealt with the problem using his own logic and a bit of empathy. Ian explained that there are policies in place, but that the priority is clearly the customer and sometimes you have to think outside of the box when dealing with it.

It’s a real shame I had to take the steps I did, to get the service I should have received in the first place, but Ian has now offered to reimburse the full cost of repair, plus the RAC sign up cost as a good faith gesture, for which I am very appreciative. His attitude may well be enough to convince me to at least consider using Evans Halshaw again in the future.

My sister had her second child on Saturday 20th February, baby Nathan. He weighed in at exactly eight pounds, with blond hair and apparently, big hands and feet!

So I’m “Uncle Dan” for a fourth time! It doesn’t matter how many times that happens, it’s still just as amazing and exciting as the first.

One thing I’ve thought about before is turning off the “nofollow” attribute in my comments to allow people to get a link that counts for something when they post on my blog. Obviously I’d need to monitor my comments more closely, but I can only see that as being a good thing. It could also spark “shallow” commenting that is designed purely to get a link out from the blog, rather than to promote actual discussion, which is definitely not what I’m looking for.

What sparked this post is a video Matt Cutts just posted, here’s what he has to say about the idea:

I’d really appreciate some feedback on this one, what do you think about the idea? Is it a bad way to encourage commenting? Would it work? Have you done the same or done it and changed back?

This is a bit of a strange post to write, as I’m naturally very excited about the challenge I’m going to be facing, but also sad to be leaving behind the great development team I’ve been working with at Stickyeyes. I’ve worked through some great challenges with the guys and learned a lot, I’m looking forward to doing the same and more in my new role.

Naturally, as with all my other posts, if anyone has any wisdom or advice they’d like to give, it would of course be greatly appreciated.

Whilst I understand that this is a less than ideal solution, as if a user can install a plugin, they can probably replace the browser anyway. However, they released an interesting update today that makes implementation a little more feasible for site owners. You can now issue the “X-UA-Compatible” string as a HTTP response header instead of a meta tag, meaning your Chrome Frame enabled pages can validate again! It also means you can, to clients that support it, serve appropriate MIME type headers that IE does not support, such as application/xhtml+xml.

The Apache configuration snippet to enable this functionality is as follows, you’ll need mod_setenvif and mod_headers enabled to use it:

<IfModule mod_setenvif.c>
<IfModule mod_headers.c>
BrowserMatch chromeframe gcf
Header append X-UA-Compatible "chrome=1" env=gcf
</IfModule>
</IfModule>

I’ve implemented it on this server, so now any Internet Explorer visitors with Chrome Frame installed going to any of my sites, will see them as I designed them originally – in Webkit.

For more information about this update to Chrome Frame, see this blog post.

Remo’s Bio:

Remo is Head of Research & Development at Stickyeyes, a search marketing agency based in Leeds. The R&D team works on a mixture of client site builds, internal reporting tools and Market Defender a search marketing intelligence tool. His team works mainly with PHP, MySQL and Apache. Remo graduated with an MSc in pure mathematics having covered programming in Fortran, Pascal, Lisp & C; he joined BT’s R&D Labs at Martlesham Heath working on large scale systems (a dozen mainframes, a few hundred Unix servers…) before getting an MBA and leaving to set up his own web development business. Remo sold the business in 2008 and joined Stickyeyes. Remo is passionate about object-orientated coding and can talk for hours about the Liskov Subsitution Principle, test driven development and solid software engineering.

The Talk – Database Optimisation:

A real life example getting more throughput with fewer queries.

Over the last year we’ve grown a database from a few hundred megabytes to just over one terabyte. The database is reported on and populated by a network of servers using PHP. As the database has grown we’ve had to look again our initial assumptions and ways of working. One table has over 2billion rows; 2.5 million rows every day are added to another table. This talk will cover how we use explain, foreign keys, normalising data without sacrificing performance, queuing and using memcache. And, how we’ve made the system run faster now than it did with a much smaller database.

Without going into too much detail, the talk basically centres around the work that myself, Wade and the rest of our team have been doing over the course of the last year and a half.

Much of the content will be familiar to those who read my blog. It’s about scaling MySQL from a couple of hundred megabyte data store in our office, to a two server set up holding over a terabyte of data, fed by tens of servers, all the whileincreasing the speed at which we could store and retrieve data. It’ll cover how we implemented beanstalkd and memcached to lessen database load, and I’d imagine it will also touch on our ongoing implementation of HAProxy load balancing.

If you’re attending the conference and this sounds interesting to you, make sure you get to the talk. Wade and I will be around as well, to answer any questions that might come up throughout the day. As always, you can also ask the questions here, and if the answer is interesting enough, it might make it into the talk (though no promises!)

Why?

Google Buzz has a lot of the hallmarks of Google Wave. It allows you to easily share a message with your friends, or publicly. It allows you to share links and photos easily. It’s got a nice UI and expands well on what the competition, Twitter, provides. However, it’s not as technically cool as Wave. Google Buzz lacks the killer feature of Wave, for me, though I know it’s going to sound incredibly sad – it’s missing the ability to drag and drop pictures from your computer to the internet.

As far as general opinions on Google Buzz go, I like it and think it stands a real chance. If nothing else, it should light some fires under the feet of the Twitter team, which can only be a good thing. Buzz has a few niggles, such alerting me whenever something changes in my stream – but then not highlighting those changes clearly enough on the resulting page, but I’m sure that’ll get sorted quickly enough. Twitter integration is nice, but it’s too slow to be useful – I don’t want to see what people were saying an hour ago.

I’m intrigued how quickly this blog entry will make it into Buzz. This blog is fed to Twitter, pings various sites on posting, and also has PubSubHubBub integrated. The theory is that it should be near-instant.

As soon as I saw this, it reminded me a lot of Google Wave. It strikes me as a way for Google to push a Wave-like service out in a way that users will understand, since many, including me, didn’t have a clue what it was for. I’m hoping that Google have carried over Wave’s best features, like the ability to drag and drop photos from your computer to upload. If they have, I think they will be taking away a key barrier to entry for “normal users” to get started sharing online, as figuring out how to share pictures on Twitter is hardly simple.

The key difference between Buzz and Wave, for me, is that they’re not trying to replace a well established system (i.e. email) with a new protocol. They are trying to compete with the current “trendy” site, perhaps thinking a little too much of their own influence, but sites come in and out of fashion all the time – email does not. They’re also giving it to all GMail users straight away, and allowing you to link it with your Twitter profile, making the potential audience pretty huge.

I’m looking forward to seeing how Google Buzz develops, and whether or not anyone actually uses it after the initial… err, Buzz… has died down. Of course, my first question is, when’s the first Wordpress “Buzz New Posts” plugin coming?