Nginx – A New Kid in Town

Posted on January 11, 2012 by David_Cowell

Nginx (pronounced Engine-X) is an alternative, open-source web server which is designed to be lightweight and high-performance and since its release in 2004 it has seen a steady increase in uptake. It’s stable, easy to configure and uses an asynchronous architecture to ensure that under heavy load that page requests are returned quickly to the end user.

Having landed $3 million in funding in October, December saw Nginx leapfrog Microsoft’s IIS web server to become the world’s second most popular choice behind Apache. According to Netcraft, Nginx now hosts 22.2 million active sites, a 1.9 million increase on November.

Nginx Performance in cPanel

If you’d like to try out this lightweight hard-hitter please get in touch; we’d be happy to set you up with an Nginx Cloud server for you to test.

UFOs in the Cloud

Posted on December 24, 2011 by David_Cowell

Earlier this week we had some amazing cloud activity in the UK. “Altocumulus Lenticularis” cloud formations are regularly mistaken for UFOs and are very common in the Himalayas and Andes but not here in the UK.

Hope you all have a very Merry Christmas!

Battery potential

Posted on November 21, 2011 by David_Cowell

Incredibly interesting to see that Northwestern University in the USA have released details of a lithium-ion battery that can hold up to 10 times the charge and recharge in 10 times the speed compared to current models. What this can mean for the technology industry is fascinating.

The capabilities of touchscreen tablets, next generation mobile telephones and ultra-portable laptops all rely heavily on the power they can source from slimline batteries but what could we achieve with server equipment? Would it start to make sense to move DC UPS away from mains source and store it onboard the chassis if you could keep it powered for hours rather than minutes in a space-efficient manner? Whereas it used to be that space was the key factor in building out new sites, it is of course power that is the important consideration now. Could we become more frivolous with our rack usage to get onboard per-server power resilience?

What about individual components? Maybe volatile storage would benefit from extended power sources in much the same way as DRAM performs now?

Bill Gates released the stat that we currently have enough batteries in globally to provide 10 minutes of the world’s power. I’ve not seen how that was calculated but it’s a lovely stat if it’s even vaguely accurate. Maybe the electric car will be able to get us all the way home soon!

Bangkok Flooding Causes World Shortage of Hard Drives

Posted on November 2, 2011 by David_Cowell

The tragic scenes in Thailand of relentless flooding have hit all of our screens this week. Reports today suggest that the flood waters are continuing to rise outside of the flood defences that new Prime Minister Yingluck Shinawatra is using to keep the heart of Bangkok (home to 12 million) mostly dry.

Over 400 Thai residents have lost their lives in the flooding but so far none of those reported have been in Bangkok itself, suggesting that the Prime Minister’s efforts are being successful.

However, the water levels along the Chao Phraya (the river that flows straight through Bangkok) are at their highest levels in days and some of the largest manufacturing plants in the world are based alongside it. Some have already suffered flooding, those that haven’t have closed because it is not safe, or even possible, for their employees to travel to work. The Thai Government has put out an official recommendation that those living in Bangkok escape the dangers of the rising water and go on holiday.

One such manufacturing plant affected by the floods is responsible for producing around 25% of the world’s hard disk drives every year; Western Digital have two Manufacturing Centres in Thailand, and in the last 24 months have increased their workforce by more than 20% to over 40,000 employees.

One of the Western Digital Manufacturing plants has already suffered from flooding

Companies such as Nidec (who manufacture more than 70% of all hard drive motors) have also been forced to temporarily suspend operations at all three of its plants in Thailand.

Not only does this massively impact Western Digital and Nidec as businesses, but the knock-on effects are already being seen here in the UK and Europe with stocks of Hard Drives thinning and restock timeframes becoming longer and vaguer. For those companies such as us who rely on the timely availability of computing components to be able to expand and grow their infrastructure in keeping with client demand, it has been essential to almost “hedge” on disk drives, stocking up before the “drought”!

I imagine that there will be a lot of companies who, in the next 6 to 12 months, find it difficult to provision services with the speed that they would normally do and find that their margins get squeezed as their costs rise. The flooding itself has a massive impact on the communities of Thailand, but the repercussions will be felt globally for a long while to come.

The beauty of ZFS

Posted on October 27, 2011 by David_Cowell

Without the underlying data, nothing else matters. Backing up your data is critical but what about silent data corruption?

The biggest problem with silent data corruption is that it is completely silent. You receive no error notifications or alerts and your systems continue on their merry way having written an erroneous bit of data to your drive. And what’s the downside? Maybe just a lost file or maybe a corrupted operating system. Who knows?

CERN’s Large Hadron Collider creates around 15 million gigabytes (15 petabytes) of data every year. That data is used to make conclusions about how the universe was created. So erroneous data would have a considerable impact on those conclusions. That’s why they ran some considerable tests to check the error rate in their data. When they checked 8.7 TB of user data for corruption – 33,700 files – they found 22 corrupted files, or 1 in every 1500 files.

That’s actually quite a considerable number when you think about it. That means that if you have a 1 TB disk in your home machine that, full with 4MB MP3s (legally purchased of course!), that you could expect 170 of them to be corrupted, unusable, lost forever.

“But surely this isn’t going to be a problem with Raid?” I hear you say? Actually one of the biggest culprits is a very common Raid configuration that we all know and love:

Raid 5
Raid 5 is very good. It creates a parity bit for the data that it writes to disk. It stripes that parity bit across the array. The parity bit value must leave the XOR of all the disks to be zero. That way if a disk is lost, you can recalculate what was on the disk by reversing the calculation.

However, every time you update the data on the disk, you must also update the parity bit. One way that errors occur, is when the data is updated, and power is lost before the parity bit is written. This leaves you with a mismatch between your check data and the real, underlying data. The only way that is going to ever be fixed is if the data is completely written over and the parity bit updated correctly. Otherwise, if you were to recreate the data from the parity check, you’d recreate data that was incorrect and you’d never know. This is called the Raid 5 Write Hole.

Because of the way this all ties together, there is also a significant performance impact to this way of working. If an update is made to the disk that is smaller than the size of a single Raid stripe, the whole stripe must be re-read in order to recalculate the parity bit for that stripe. You were making a very small write and that has incurred a much larger “read” and another, much larger “write”.

There are solutions to these problems but they are all expensive and definitely don’t meet the description of Redundant Array of Inexpensive Disks!

ZFS
ZFS is a transactional filesystem in exactly the same way as most database systems are transactional. All data is committed at once to the disk to prevent “writes” being partially completed. Each block of data has its own checksum which is saved at its pointer. This means that whenever a block of data is accessed it is compared with its checksum. If this is found to differ then the filesystem can heal the block of data so that it is correct before being used.

If ZFS is used with Hardware RAID then it can’t guarantee that at a hardware level you won’t end up with the same “hole” as I outlined for Raid 5. So it needs to be in complete control of underlying disks and the system should only use HBA (Host Bus Adapters) to access the drives.

ZFS isn’t a new technology by any means. We’ve been utilising it for many years. However, it is still relatively unknown and underused for what is effectively a Redundant Array of Inexpensive Disks!

Blackberry eating a Ploughman’s

Posted on October 11, 2011 by David_Cowell

Following Blackberry’s 20 hour blackout yesterday they have suffered further problems today, only hours after restoring service to its EMEA customer base.

The crash in the Slough DC has caused ranging levels of disruption to business and personal Blackberry users alike across Europe, the Middle East and Africa affecting E-mail and SMS messaging facilities.

RIM, who own Blackberry, have given very little information to its customers about the cause of the issues and have merely apologised for the “inconvenience” caused. Given the impact to end users it is a shame that RIM haven’t taken a more adult approach to their communications. Considering their dwindling market share to other smartphone manufacturers it is even more disappointing that the approach taken hasn’t involved greater disclosure.

By not releasing a clear and explanatory statement they also put all their Customer Service reps into the firing line. It’s one thing to control Comms but quite another to show your own staff such low amounts of respect for something they have no control over.

In my long experience in the hosting industry the problem rarely stems from the service impact but from the way in which it is handle and communicated. If you treat your clients and customers with contempt for wanting to know what’s going on, expect derision, mockery, hearsay, assumption, conjecture, exaggeration and amplification in return.

Right now RIM might as well have turned their whole DC off deliberately and be sitting, eating a Ploughman’s in the Three Tuns for all we know. Set the record straight, be open and let us all know what’s gone wrong and afterwards tell us how you’re going to prevent it happening again. Treat us like the adults that we are and we’ll understand and stop guessing.

BT too reliant on power

Posted on October 4, 2011 by David_Cowell

BT suffered a massive power failure yesterday afternoon after a major exchange in Birmingham went down. The outage affected thousands of business customers’ office connections and left them without internet connectivity for their staff. So what can you do to prevent this happening to you?

“It’s very important to design your infrastructure in proportion to the risks, and the impact of those risks becoming a reality.”

Today, we’ve seen a surge of companies looking to move their hosting into the Cloud and away from their offices. And why wouldn’t you host your services in a site that is designed from the ground up to have multiple power and network connections? Our Data Center, for instance, has multiple power sources, each supported by N+1 UPS and Diesel Generators meaning that even if power were lost on both power feeds, our services would still be live.

In yesterday’s example at least those business customers affected would know that their websites, eCommerce systems and online services were available to their clients. Add in a secondary internet connection such as a 3G dongle and suddenly your staff can still provide personal service as well.

Ultimately, it doesn’t take a lot of planning to beat the problems imposed on your business by the fallout of a power cut and it doesn’t cost much either.

Maybe it’s worth looking at how your business would cope in the event of a power or network outage?

It’s Definitely Not Easy Out There

Posted on September 22, 2011 by David_Cowell

On the day when £64 billion was wiped off the UK’s top 100 companies it’s easy to lose perspective on the quantum of the issue and how it affects small and medium sized businesses.

Large drops in the FTSE 100 are heavily reported and affect consumer confidence in an already tough environment. Expectations of consumers is that with less in their pocket to spend that companies should be keener with their pricing, offering goods and services at a lower rate in the face of rising inflation. According to the Business Inflation Guide (BIG), published by insurer MORE TH>N BUSINESS, there has been a sharp rise in costs incurred by small businesses at a rate of 3.6 per cent in the first quarter of 2011. Businesses are being squeezed from both sides.

Business rates are set to rise in Scotland by around 23% in the next handful of years according to new reports out this week. Credit costs are also on the rise along with energy and fuel prices.

I think we’re really stretching things to hope that the Chinese will come to our aid. As far as I know they’ve only shown interest in investing where there are long-term political gains to support the financial benefits. Going down this route only means we’ll be further mortgaging our futures… Something that got us in today’s mess!

Individuals are also obviously affected. In the States it has just been announced that health insurance is to rise 5.4% next year, this side of the pond, individuals are paying more VAT, and even the price of bad has risen by 38% in the last three years!

However, there are some good stories out there. Easyjet have revised upwards their profit forecasts on the back of an increase in business users indicating a switch in mindset by those that sign off the expenses. This week I tweeted about Forbes magazine’s article professing that Cloud Computing May be a Shot in the Arm our Economy Need and actually I’m very lucky to work in an industry that, despite the economic slump, is very much in a boom. I suppose it makes perfect sense why that would be the case as well. Afterall, outsourcing your hosting has been more economic for companies for over a decade and now, with Cloud, it’s even more cost effective, even more reliable and even simpler to manage! And that has to be the theme for success surely? If you want to make a success of yourself and your business in an economic slump, review your costs and cut wisely. They say that every economic downturn breeds entrepreneurs, but I don’t believe it has to be limited to the few in this way. We can all look at how we’ve run things over the last decade and revise our budgets to meet the changes we face as the economy slowly recovers.