Welcome!

Cloud Expo Authors: Elizabeth White, Lisa Pope, Pat Romanski, Yeshim Deniz, Liz McMillan

Related Topics: Cloud Expo, Java, SOA & WOA, Linux, Security, SDN Journal

Cloud Expo: Article

The Facts About Cloud High Availability and Disaster Recovery

Understanding the facts about HA and DR in the cloud can help you make informed decisions

Enterprises are moving more and more applications to the cloud. Gartner predicts that the bulk of new IT spending by 2016 will be for cloud computing platforms and applications and that nearly half of large enterprises will have cloud deployments by the end of 2017.1

The far-reaching impact of cloud computing is summarized in a recent McKinsey report on disruptive technologies: "Cloud technology has the potential to improve productivity across $3 trillion in global enterprise IT spending, as well as enabling the creation of new online products and services for billions of consumers and millions of businesses alike."2

For many organizations, moving applications that can tolerate brief periods of downtime to the cloud is a straightforward decision with clear benefits. However, concerns about how to provide high availability and disaster protection in the cloud may make this decision more difficult for business-critical applications such as SQL, SAP, and Exchange. Understanding the facts about HA and DR in the cloud can help you make informed decisions about moving applications to the cloud, while ensuring the important business operations that depend on them are protected from downtime and data loss.

Fact #1: You need high availability protection in a cloud.
Do not assume that your cloud environment provides high availability protection, unless you have specifically configured it for HA. In fact, according to a recent study: "The average unavailability of cloud services is 10 hours per year or more, while the average availability is estimated to be 99.9% far less than the expected availability of business critical applications."3 That is the equivalent of more than a day of downtime. In fact, in 2014, Microsoft Windows Azure, Google, and Amazon Web Services all had some measure of service interruptions or downtime ranging from 4 minutes to several hours.4

For business critical applications, the redundancy that you can get with some cloud solutions, such as Windows Azure, is not enough. When you consider the cost of a minute of downtime for applications, such as SQL Server, Oracle, and SAP that may run many of your key business processes, it becomes clear that you need true high availability and disaster recovery protection. You need to ensure that end users have immediate access to data and applications in the event of a local failure, a regional disaster or anything in between.

However, the traditional way of providing high availability protection is to build a cluster using two identical servers - a primary server and a standby server -  with shared (typically SAN) storage. If the primary server fails, the application operation is moved to the standby server, which has immediate access to the same storage. The problem is that SANs are not only expensive to buy, manage, and maintain, they are simply not an option in public cloud offerings. There are, however, high availability solutions that can be used in a cloud that do not require a SAN.

Fact #2: You can build a cluster in a cloud.
Even though you cannot have a SAN in a cloud, you can build a cluster for high availability protection. In a Windows cloud, you simply add SANLess cluster software to your Windows Server Failover Cluster (WSFC). The SANLess software uses real time, block level replication to keep local storage in two geographic regions of the cloud synchronized. If there is an outage, the application operation is automatically moved to the remote instance, which has immediate access to current data. The synchronized storage looks to the WSFC like a traditional shared storage so there is no added complexity or specialized skills needed to build or manage a SANLess cluster. In fact, a SANLess cluster is easy to manage and has the added benefit of eliminating the single point of failure risk of a SAN. SANLess clusters also provide complete configuration flexibility, allowing you to replicate between physical, virtual, cloud, and hybrid cloud environment as well as between SAN and SANLess clusters.

Fact #3: You can have geographically separated nodes for DR in a cloud.
While providing high availability within the cloud will protect you from normal hardware failures and other unexpected outages within an availability zone (Amazon) or fault domain (Azure), you still need to protect against regional disasters. The easiest solution is to configure a multisite (geographically separated) cluster.

One effective method is to build a SANLess cluster within a cloud and extend it for disaster recovery by adding another node(s) in an alternate data center or a different geographic region within the cloud. Unlike traditional clusters that require you to have identical hardware and software in every node, a SANLess cluster allows you to mix physical, cloud and hybrid cloud configurations. The benefits of a DR configuration are clear. For example, simply adding a third, geographically separated node to your SANLess cluster in a Windows Azure cloud can give you a recovery point objective (RPO) of near zero data loss and a recovery time objective (RTO) of just about one minute.

Fact #4: You can create a cluster that mixes cloud and on-premises nodes.
You can use your on-premises data center as your primary location with a failover cluster to provide high availability protection and use the cloud as your hot standby DR site. This is a very cost-effective alternative to building out your own DR site, or renting rack space in a business continuity facility. In this case, the on-premises servers can be your choice of traditional SAN-based clusters, SANLess clusters, or even single servers not currently participating in a cluster.

The objective of having a "hot" standby DR site is to have standby servers up and running as quickly as possible in the DR site with access to a copy of the most recent application data. In the event of a disaster, recovery is automatic and immediate. A multisite cluster is an effective way to implement a hot standby DR site. In this case, the SANLess date. In the event of a forecasted disaster, such as a storm or a flood, applications can be moved to the cloud before potential disaster strikes. In the event of an unexpected disaster, applications can be recovered manually or in some cases automatically, depending upon the quorum configuration. This mix of cloud and on-premises nodes gives you an excellent RTO and RPO with minimal investment in infrastructure.

Fact #5: HA and DR in a cloud can be easy and highly cost-effective.
If you choose a SANLess software that provides an intuitive configuration interface, you can create a standard WSFC in a cloud in minutes without specialized skills. A SANLess cluster can help you realize significant cost savings in several ways. First, in a Microsoft SQL Server environment a SANLess cluster can give you high availability with SQL Server Standard Edition software licenses without requiring you to upgrade to costly SQL Server Enterprise Edition.

Second, you can realize hundreds of thousands of dollars in savings with a SANLess by eliminating the total cost of ownership (TCO) associated with a SAN. The savings in TCO include the SAN hardware acquisition costs; the power, cooling, and data center floor space costs; and the ongoing labor cost of specialized SAN administration.

If you are thinking about moving your important applications to the cloud, you need to consider how you will protect those applications from downtime and data loss. While traditional SAN-based clusters are not possible in these environments, SANLess clusters can provide an easy, cost-efficient alternative. These clusters not only provide high availability protection, but also enable significantly greater configuration flexibility and potentially dramatic savings in both licensing costs and SAN TCO.

Notes

1"Gartner Says Cloud Computing Will Become the Bulk of New IT Spend by 2016."

2 Manyika, James and Michael Chui, et al, "Disruptive technologies: Advances that will transform life, business, and the global economy," McKinsey Global Institute (May 2013) 

3Whittaker, Josh, "Amazon Web Services Suffers Outage, Takes Out Vine, Instagram, Others with it," ZDNet, (August 26, 2013)

4Mackay, Martin, "Downtime Report: Top Ten Outages in 2013," Business2Community.com, (December 2013)

More Stories By Jerry Melnick

Jerry Melnick ([email protected]) is responsible for defining corporate strategy and operations at SIOS Technology Corp. (www.us.sios.com), maker of SIOS SAN and #SANLess cluster software (www.clustersyourway.com). He more than 25 years of experience in the enterprise and high availability software industries. He holds a Bachelor of Science degree from Beloit College with graduate work in Computer Engineering and Computer Science at Boston University.

Comments (0)

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.


@CloudExpo Stories
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Ar...
Leysin American School is an exclusive, private boarding school located in Leysin, Switzerland. Leysin selected an OpenStack-powered, private cloud as a service to manage multiple applications and provide development environments for students across the institution. Seeking to meet rigid data sovereignty and data integrity requirements while offering flexible, on-demand cloud resources to users, Leysin identified OpenStack as the clear choice to round out the school's cloud strategy. Additional...
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, a...
The major cloud platforms defy a simple, side-by-side analysis. Each of the major IaaS public-cloud platforms offers their own unique strengths and functionality. Options for on-site private cloud are diverse as well, and must be designed and deployed while taking existing legacy architecture and infrastructure into account. Then the reality is that most enterprises are embarking on a hybrid cloud strategy and programs. In this Power Panel at 15th Cloud Expo (http://www.CloudComputingExpo.com...
Technology is enabling a new approach to collecting and using data. This approach, commonly referred to as the "Internet of Things" (IoT), enables businesses to use real-time data from all sorts of things including machines, devices and sensors to make better decisions, improve customer service, and lower the risk in the creation of new revenue opportunities. In his General Session at Internet of @ThingsExpo, Dave Wagstaff, Vice President and Chief Architect at BSQUARE Corporation, discuss the ...
"BSQUARE is in the business of selling software solutions for smart connected devices. It's obvious that IoT has moved from being a technology to being a fundamental part of business, and in the last 18 months people have said let's figure out how to do it and let's put some focus on it, " explained Dave Wagstaff, VP & Chief Architect, at BSQUARE Corporation, in this SYS-CON.tv interview at @ThingsExpo, held Nov 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
The 4th International DevOps Summit, co-located with16th International Cloud Expo – being held June 9-11, 2015, at the Javits Center in New York City, NY – announces that its Call for Papers is now open. Born out of proven success in agile development, cloud computing, and process automation, DevOps is a macro trend you cannot afford to miss. From showcase success stories from early adopters and web-scale businesses, DevOps is expanding to organizations of all sizes, including the world's large...
Verizon Enterprise Solutions is simplifying the cloud-purchasing experience for its clients, with the launch of Verizon Cloud Marketplace, a key foundational component of the company's robust ecosystem of enterprise-class technologies. The online storefront will initially feature pre-built cloud-based services from AppDynamics, Hitachi Data Systems, Juniper Networks, PfSense and Tervela. Available globally to enterprises using Verizon Cloud, Verizon Cloud Marketplace provides a one-stop shop fo...
Software-driven innovation is becoming a primary approach to how businesses create and deliver new value to customers. A survey of 400 business and IT executives by the IBM Institute for Business Value showed businesses that are more effective at software delivery are also more profitable than their peers nearly 70 percent of the time (1). DevOps provides a way for businesses to remain competitive, applying lean and agile principles to software development to speed the delivery of software that ...

ARMONK, N.Y., Nov. 20, 2014 /PRNewswire/ --  IBM (NYSE: IBM) today announced that it is bringing a greater level of control, security and flexibility to cloud-based application development and delivery with a single-tenant version of Bluemix, IBM's

"Our premise is Docker is not enough. That's not a bad thing - we actually love Docker. At ActiveState all our products are based on open source technology and Docker is an up-and-coming piece of open source technology," explained Bart Copeland, President & CEO of ActiveState Software, in this SYS-CON.tv interview at DevOps Summit at Cloud Expo®, held Nov 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
DevOps Summit 2015 New York, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that it is now accepting Keynote Proposals. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development cycles that produce software that is obsolete...
Infor has announced a new feature Infor CloudSuite™ Aerospace & Defense (A&D) to aid compliance with International Traffic in Arms Regulations (ITAR). The ITAR function will serve as a complementary function for new or existing Infor CloudSuite A&D customers, to facilitate compliance for Infor customers that are creating a US defense article or performing a US defense service and wish to benefit from cloud-services. The ITAR regulation serves to manage handling and access requirements for dat...
What do a firewall and a fortress have in common? They are no longer strong enough to protect the valuables housed inside. Like the walls of an old fortress, the cracks in the firewall are allowing the bad guys to slip in - unannounced and unnoticed. By the time these thieves get in, the damage is already done and the network is already compromised. Intellectual property is easily slipped out the back door leaving no trace of forced entry. If we want to reign in on these cybercriminals, it's hig...
Bit6 today issued a challenge to the technology community implementing Web Real Time Communication (WebRTC). To leap beyond WebRTC’s significant limitations and fully leverage its underlying value to accelerate innovation, application developers need to consider the entire communications ecosystem.
The 3rd International @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that it is now accepting Keynote Proposals. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - computers, smartphones, tablets, and sensors - connected to th...
The Internet of Things is not new. Historically, smart businesses have used its basic concept of leveraging data to drive better decision making and have capitalized on those insights to realize additional revenue opportunities. So, what has changed to make the Internet of Things one of the hottest topics in tech? In his session at @ThingsExpo, Chris Gray, Director, Embedded and Internet of Things, discussed the underlying factors that are driving the economics of intelligent systems. Discover ...
Cochlear Limited, the global leader in implantable hearing solutions, has selected AppZero for easy migration of its Microsoft Windows Server 2003 applications, a major priority for IT organizations before Microsoft ends support on July 14, 2015. AppZero software enables server application migration from old operating systems to new platforms or clouds and has been proven to be ten times faster, more reliable and efficient than alternative approaches.
Fundamentally, SDN is still mostly about network plumbing. While plumbing may be useful to tinker with, what you can do with your plumbing is far more intriguing. A rigid interpretation of SDN confines it to Layers 2 and 3, and that's reasonable. But SDN opens opportunities for novel constructions in Layers 4 to 7 that solve real operational problems in data centers. "Data center," in fact, might become anachronistic - data is everywhere, constantly on the move, seemingly always overflowing. Net...
SYS-CON Media announced today the IBM, which offers the world’s deepest portfolio of technologies and expertise that are transforming the future of work, has launched ad campaigns on SYS-CON’s numerous online magazines such as Cloud Computing Journal, DevOps Journal, Virtualization Journal, and IoT Journal. IBM's campaigns focus on application testing, improving application development processes, common challenges in testing composite applications, continuous testing as part of the DevOps lifec...