Welcome!

Agile Computing Authors: AppNeta Blog, Carmen Gonzalez, Elizabeth White, Jason Bloomberg, Xenia von Wedel

Related Topics: Containers Expo Blog, @CloudExpo

Containers Expo Blog: Article

Cloud Computing and Reliability

The Cloud offers some enticing advantages with respect to reliability

Eric Novikoff's Blog

IT managers and pundits speak of the reliability of a system in "nines." Two nines is the same as 99%, which comes to (100%-99%)*365 or 3.65 days of downtime per year, which is typical for non-redundant hardware if you include the time to reload the operating system and restore backups (if you have them) after a failure. Three nines is about 8 hours of downtime, four nines is about 52 minutes and the holy grail of 5 nines is 7 minutes.

From a users' point of view, downtime is downtime, but for a provider/vendor/web site manager, downtime is divided into planned and unplanned. Cloud computing can offer some benefits for planned downtime, but the place that it can have the largest effect on a business is in reducing unplanned downtime.

Planned downtime is usually the result of having to do some sort of software maintenance or release process, which is usually outside the domain of the cloud vendor, unless that vendor also offers IT operations services. Other sources of planned downtime are upgrades or scheduled equipment repairs. Most cloud vendors have some planned downtime, but because their business is based on providing high uptime, scheduled downtimes are kept to a minimum.

Unplanned downtime is where cloud vendors have the most to offer, and also the most to lose. Recent large outages at Amazon and Google have shown that even the largest cloud vendors can still have glitches that take considerable time to repair and give potential cloud customers a scare (perhaps it is because they didn't take some planned downtime??) On the other hand, cloud vendors have the experienced staff and proven processes that should produce overall hardware and network reliability that meets or exceeds that of the average corporate data center, and far exceeds anything you can achieve with colocated or self-managed servers.

However, despite claims of reliablity, few cloud vendors have tight SLAs (service level agreements) that promise controlled downtime or offer rebates for excess downtime. Amazon goes the opposite direction and doesn't offer any uptime guarantees, even cautioning users that their instance (or server) can disappear at any time and that they should plan accordingly. AppLogic-based clouds, provided by companies such as ENKI, are capable of offering better guarantees of uptime because of its inherent self-healing capabilities that can enable 3-4 nines of uptime. (The exact number depends on how the AppLogic system is set up and administered, which affects the time needed for the system to heal itself.) However, any cloud computing system, even even those based on AppLogic or similar technologies, can experience unplanned downtime for a variety of reasons, including the common culprit of human error. While I believe it is possible to produce a cloud computing service that exceeds 4-9s of uptime, the costs would be so high that few would buy it when they compared the price to the average cloud offering.


When you're purchasing cloud computing, it makes sense to look at the SLA of the vendor as well as the reliability of the underlying technology. But if your needs for uptime exceed that which the vendors and their technology can offer, there are time-honored techniques for improving it, most of which involve doubling the amount of computing nodes in your application. There's an old adage that each additional "9" of uptime you get doubles your cost, and that's because you need backup systems that are in place to take over if the primaries fail. This involves creating a system architecture for your application that allows for either active/passive failover (meaning that the backup nodes are running but not doing anything) or active/active failover (meaning that the backup nodes are normally providing application computing capability).

These solutions can be implemented in any cloud technology but they always require extra design and configuration effort for your application, and they should be tested rigorously to make sure they will work when the chips are down. Failover solutions are generally less expensive to implement in the Cloud because of the on-demand or pay-as-you go nature of cloud services, which means that you can easily size the backup server nodes to meet your needs and save on computing resources.

An important component of reliability is a good backup strategy. With cloud computing systems like AppLogic offering highly reliable storage as part of the package, many customers are tempted to skip backup. But data loss and the resulting unplanned downtime can result not just from failures in the cloud platform, but also software bugs, human error, or malfeasance such as hacking. If you don't have a backup, you'll be down a long time - and this applies equally to cloud and non-cloud solutions. The advantages of cloud solutions is that there is usually an inexpensive and large storage facility coupled with the cloud computing offering which gives you a convenient place to store your backups.

For the truly fanatical, backing up your data from one cloud vendor to another provides that extra measure of security. It pays to think through your backup strategy because most of today's backup software packages or remote backup services were designed for physical servers and not virtual environments having many virtual servers such as you might find in the cloud. This can mean very high software costs for doing backup if your backup software charges on a "per server" basis and your application is spread across many instances. If your cloud vendor has a backup offering, usually they have found a way to make backup affordable even if your application consists of many compute instances.

Another aspect of reliability that often escapes cloud computing customers new to the world of computing services is monitoring. It's very hard to react to unplanned downtime if you don't know your system is down. It's also hard to avoid unplanned downtime if you don't know you're about to run out of disk space or memory, or perhaps your application is complaining about data corruption. A remote monitoring service can scan your servers in the cloud on a regular basis for faults, application problems, or even measure the performance of your application (like how long it takes to buy a widget in your web store) and report to you if anything is out of the ordinary. I say "service" because if you were to install your own monitoring server into your cloud and the cloud went down, so would your monitoring! At ENKI, we solve this problem by having our monitoring service hosted in a separate data center and under a different software environment than our primary cloud hosting service.

The last aspect of reliability is security. However, that would require another entire article to cover, since security in the cloud is a complex and relatively new topic.

To sum up, the Cloud offers some enticing advantages with respect to reliability, perhaps the largest of which is that you can give your data center operations responsibility to someone who theoretically can do a much better job at a lower cost than you can. However, to get very good reliability, you must still apply traditional approaches of redundancy and observability that have been used in physical data centers for decades - or, you have to find a cloud computing services provider that can implement them for you.

More Stories By Eric Novikoff

Eric Novikoff is COO of ENKI, A Cloud Services Vendor. He has over 20 years of experience in the electronics and software industries, over a range of positions from integrated circuit designer to software/hardware project manager, to Director of Development at an Internet Software As A Service startup, Netsuite.com. His technical, project, and financial management skills have been honed in multiple positions at Hewlett-Packard and Agilent Technologies on a variety of product lines, including managing the development and roll-out of a worldwide CRM and sales automation application for Agilent's $350 million Automatic Test Equipment business. Novikoff also has a strong interest in SME (Small/Medium Size Enterprise) management, process development, and operations as a consequence of working at a web based ERP service startup serving SMEs, and through his small-business ERP consulting work.

Comments (1) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
faseidl 09/10/08 11:45:52 AM EDT

Despite what many pundits have to say, reliability issues will not be the downfall of cloud computing. Using cloud computing does not mean neglecting to architect solutions that meet their business requirements, including reliability requirements.

I wrote more about this idea here:

Cloud Computing and Reliability
http://faseidl.com/public/item/212584

@ThingsExpo Stories
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smar...
Internet of @ThingsExpo, taking place June 6-8, 2017 at the Javits Center in New York City, New York, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. @ThingsExpo New York Call for Papers is now open.
"ReadyTalk is an audio and web video conferencing provider. We've really come to embrace WebRTC as the platform for our future of technology," explained Dan Cunningham, CTO of ReadyTalk, in this SYS-CON.tv interview at WebRTC Summit at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
Everyone knows that truly innovative companies learn as they go along, pushing boundaries in response to market changes and demands. What's more of a mystery is how to balance innovation on a fresh platform built from scratch with the legacy tech stack, product suite and customers that continue to serve as the business' foundation. In his General Session at 19th Cloud Expo, Michael Chambliss, Head of Engineering at ReadyTalk, discussed why and how ReadyTalk diverted from healthy revenue and mor...
In an era of historic innovation fueled by unprecedented access to data and technology, the low cost and risk of entering new markets has leveled the playing field for business. Today, any ambitious innovator can easily introduce a new application or product that can reinvent business models and transform the client experience. In their Day 2 Keynote at 19th Cloud Expo, Mercer Rowe, IBM Vice President of Strategic Alliances, and Raejeanne Skillern, Intel Vice President of Data Center Group and G...
Extracting business value from Internet of Things (IoT) data doesn’t happen overnight. There are several requirements that must be satisfied, including IoT device enablement, data analysis, real-time detection of complex events and automated orchestration of actions. Unfortunately, too many companies fall short in achieving their business goals by implementing incomplete solutions or not focusing on tangible use cases. In his general session at @ThingsExpo, Dave McCarthy, Director of Products...
You have great SaaS business app ideas. You want to turn your idea quickly into a functional and engaging proof of concept. You need to be able to modify it to meet customers' needs, and you need to deliver a complete and secure SaaS application. How could you achieve all the above and yet avoid unforeseen IT requirements that add unnecessary cost and complexity? You also want your app to be responsive in any device at any time. In his session at 19th Cloud Expo, Mark Allen, General Manager of...
Data is the fuel that drives the machine learning algorithmic engines and ultimately provides the business value. In his session at Cloud Expo, Ed Featherston, a director and senior enterprise architect at Collaborative Consulting, discussed the key considerations around quality, volume, timeliness, and pedigree that must be dealt with in order to properly fuel that engine.
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
Businesses and business units of all sizes can benefit from cloud computing, but many don't want the cost, performance and security concerns of public cloud nor the complexity of building their own private clouds. Today, some cloud vendors are using artificial intelligence (AI) to simplify cloud deployment and management. In his session at 20th Cloud Expo, Ajay Gulati, Co-founder and CEO of ZeroStack, will discuss how AI can simplify cloud operations. He will cover the following topics: why clou...
As ridesharing competitors and enhanced services increase, notable changes are occurring in the transportation model. Despite the cost-effective means and flexibility of ridesharing, both drivers and users will need to be aware of the connected environment and how it will impact the ridesharing experience. In his session at @ThingsExpo, Timothy Evavold, Executive Director Automotive at Covisint, discussed key challenges and solutions to powering a ride sharing and/or multimodal model in the age ...
The Internet of Things (IoT) promises to simplify and streamline our lives by automating routine tasks that distract us from our goals. This promise is based on the ubiquitous deployment of smart, connected devices that link everything from industrial control systems to automobiles to refrigerators. Unfortunately, comparatively few of the devices currently deployed have been developed with an eye toward security, and as the DDoS attacks of late October 2016 have demonstrated, this oversight can ...
Bert Loomis was a visionary. This general session will highlight how Bert Loomis and people like him inspire us to build great things with small inventions. In their general session at 19th Cloud Expo, Harold Hannon, Architect at IBM Bluemix, and Michael O'Neill, Strategic Business Development at Nvidia, discussed the accelerating pace of AI development and how IBM Cloud and NVIDIA are partnering to bring AI capabilities to "every day," on-demand. They also reviewed two "free infrastructure" pr...
Major trends and emerging technologies – from virtual reality and IoT, to Big Data and algorithms – are helping organizations innovate in the digital era. However, to create real business value, IT must think beyond the ‘what’ of digital transformation to the ‘how’ to harness emerging trends, innovation and disruption. Architecture is the key that underpins and ties all these efforts together. In the digital age, it’s important to invest in architecture, extend the enterprise footprint to the cl...
What happens when the different parts of a vehicle become smarter than the vehicle itself? As we move toward the era of smart everything, hundreds of entities in a vehicle that communicate with each other, the vehicle and external systems create a need for identity orchestration so that all entities work as a conglomerate. Much like an orchestra without a conductor, without the ability to secure, control, and connect the link between a vehicle’s head unit, devices, and systems and to manage the ...
We are always online. We access our data, our finances, work, and various services on the Internet. But we live in a congested world of information in which the roads were built two decades ago. The quest for better, faster Internet routing has been around for a decade, but nobody solved this problem. We’ve seen band-aid approaches like CDNs that attack a niche's slice of static content part of the Internet, but that’s it. It does not address the dynamic services-based Internet of today. It does...
Successful digital transformation requires new organizational competencies and capabilities. Research tells us that the biggest impediment to successful transformation is human; consequently, the biggest enabler is a properly skilled and empowered workforce. In the digital age, new individual and collective competencies are required. In his session at 19th Cloud Expo, Bob Newhouse, CEO and founder of Agilitiv, drew together recent research and lessons learned from emerging and established compa...
Connected devices and the industrial internet are growing exponentially every year with Cisco expecting 50 billion devices to be in operation by 2020. In this period of growth, location-based insights are becoming invaluable to many businesses as they adopt new connected technologies. Knowing when and where these devices connect from is critical for a number of scenarios in supply chain management, disaster management, emergency response, M2M, location marketing and more. In his session at @Th...
"Dice has been around for the last 20 years. We have been helping tech professionals find new jobs and career opportunities," explained Manish Dixit, VP of Product and Engineering at Dice, in this SYS-CON.tv interview at 19th Cloud Expo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.
"We're a cybersecurity firm that specializes in engineering security solutions both at the software and hardware level. Security cannot be an after-the-fact afterthought, which is what it's become," stated Richard Blech, Chief Executive Officer at Secure Channels, in this SYS-CON.tv interview at @ThingsExpo, held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA.