Click here to close now.

Welcome!

SDN Journal Authors: Yeshim Deniz, Pat Romanski, Carmen Gonzalez, Liz McMillan, Elizabeth White

Related Topics: Cloud Expo, Java, Microservices Journal, 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
You often hear the two titles of "DevOps" and "Immutable Infrastructure" used independently. In his session at DevOps Summit, John Willis, Technical Evangelist for Docker, will cover the union between the two topics and why this is important. He will cover an overview of Immutable Infrastructure then show how an Immutable Continuous Delivery pipeline can be applied as a best practice for "DevOps." He will end the session with some interesting case study examples.
Docker is becoming very popular--we are seeing every major private and public cloud vendor racing to adopt it. It promises portability and interoperability, and is quickly becoming the currency of the Cloud. In his session at DevOps Summit, Bart Copeland, CEO of ActiveState, discussed why Docker is so important to the future of the cloud, but will also take a step back and show that Docker is actually only one piece of the puzzle. Copeland will outline the bigger picture of where Docker fits a...
SYS-CON Media named Andi Mann editor of DevOps Journal. DevOps Journal is focused on this critical enterprise IT topic in the world of cloud computing. DevOps Journal brings valuable information to DevOps professionals who are transforming the way enterprise IT is done. Andi Mann, Vice President, Strategic Solutions, at CA Technologies, is an accomplished digital business executive with extensive global expertise as a strategist, technologist, innovator, marketer, communicator, and thought lea...
Even though it’s now Microservices Journal, long-time fans of SOA World Magazine can take comfort in the fact that the URL – soa.sys-con.com – remains unchanged. And that’s no mistake, as microservices are really nothing more than a new and improved take on the Service-Oriented Architecture (SOA) best practices we struggled to hammer out over the last decade. Skeptics, however, might say that this change is nothing more than an exercise in buzzword-hopping. SOA is passé, and now that people are ...
There is little doubt that Big Data solutions will have an increasing role in the Enterprise IT mainstream over time. 8th International Big Data Expo, co-located with 17th International Cloud Expo - to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA - has announced its Call for Papers is open. As advanced data storage, access and analytics technologies aimed at handling high-volume and/or fast moving data all move center stage, aided by the cloud computing bo...
"People are a lot more knowledgeable about APIs now. There are two types of people who work with APIs - IT people who want to use APIs for something internal and the product managers who want to do something outside APIs for people to connect to them," explained Roberto Medrano, Executive Vice President at SOA Software, in this SYS-CON.tv interview at Cloud Expo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
The 5th International DevOps Summit, co-located with 17th International Cloud Expo – being held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is 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...
Discussions about cloud computing are evolving into discussions about enterprise IT in general. As enterprises increasingly migrate toward their own unique clouds, new issues such as the use of containers and microservices emerge to keep things interesting. In this Power Panel at 16th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists will address the state of cloud computing today, and what enterprise IT professionals need to know about how the latest topics and trends affec...
The 17th International Cloud Expo has announced that its Call for Papers is open. 17th International Cloud Expo, to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, brings together Cloud Computing, APM, APIs, Microservices, Security, Big Data, Internet of Things, DevOps 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 bu...
Compute virtualization has been transformational, yet security policy implementation and enforcement has lagged behind in agility and automation. There are a number of key considerations when implementing policy in private and hybrid clouds. In his session at 15th Cloud Expo, Malcolm Rieke, the Director of Product Management at Catbird, discussed the impact of this new paradigm and what organizations can do today to safely move to software-defined network and compute architectures, including: ...
An effective way of thinking in Big Data is composed of a methodical framework for dealing with the predicted shortage of 50-60% of the qualified Big Data resources in the U.S. This holistic model comprises the scientific and engineering steps that are involved in accelerating Big Data solutions: problem, diagnosis, facts, analysis, hypothesis, solution, prototype and implementation. In his session at Big Data Expo®, Tony Shan focused on the concept, importance, and considerations for each of t...
There has been a lot of discussion recently in the DevOps space over whether there is a unique form of DevOps for large enterprises or is it just vendors looking to sell services and tools. In his session at DevOps Summit, Chris Riley, a technologist, discussed whether Enterprise DevOps is a unique species or not. What makes DevOps adoption in the enterprise unique or what doesn’t? Unique or not, what does this mean for adopting DevOps in enterprise size organizations? He also explored differe...
Cloud Foundry open Platform as a Service makes it easy to operate, scale and deploy application for your dedicated cloud environments. It enables developers and operators to be significantly more agile, writing great applications and deliver them in days instead of months. Cloud Foundry takes care of all the infrastructure and network plumbing that you need to build, run and operate your applications and can do this while patching and updating systems and services without any downtime.
Cloud and Big Data present unique dilemmas: embracing the benefits of these new technologies while maintaining the security of your organization's assets. When an outside party owns, controls and manages your infrastructure and computational resources, how can you be assured that sensitive data remains private and secure? How do you best protect data in mixed use cloud and big data infrastructure sets? Can you still satisfy the full range of reporting, compliance and regulatory requirements? In...
T-Mobile has been transforming the wireless industry with its “Uncarrier” initiatives. Today as T-Mobile’s IT organization works to transform itself in a like manner, technical foundations built over the last couple of years are now key to their drive for more Agile delivery practices. In his session at DevOps Summit, Martin Krienke, Sr Development Manager at T-Mobile, will discuss where they started their Continuous Delivery journey, where they are today, and where they are going in an effort ...
Big Data is amazing, it's life changing and yes it is changing how we see our world. Big Data, however, can sometimes be too big. Organizations that are not amassing massive amounts of information and feeding into their decision buckets, smaller data that feeds in from customer buying patterns, buying decisions and buying influences can be more useful when used in the right way. In their session at Big Data Expo, Ermanno Bonifazi, CEO & Founder of Solgenia, and Ian Khan, Global Strategic Positi...
Storage administrators find themselves walking a line between meeting employees’ demands to use public cloud storage services, and their organizations’ need to store information on-premises for security, performance, cost and compliance reasons. However, as file sharing protocols like CIFS and NFS continue to lose their relevance, simply relying only on a NAS-based environment creates inefficiencies that hurt productivity and the bottom line. IT wants to implement cloud storage it can purchase a...
The cloud is everywhere and growing, and with it SaaS has become an accepted means for software delivery. SaaS is more than just a technology, it is a thriving business model estimated to be worth around $53 billion dollars by 2015, according to IDC. The question is - how do you build and scale a profitable SaaS business model? In his session at 15th Cloud Expo, Jason Cumberland, Vice President, SaaS Solutions at Dimension Data, discussed the common mistakes businesses make when transitioning t...
Are your Big Data initiatives resulting in Big Impact or Big Mess? In her session at Big Data Expo, Penelope Everall Gordon, Emerging Technology Strategist at 1Plug Corporation, shared her successes in improving Big Decision outcomes by building stories compelling to the target audience – and her failures when she lost sight of the plotline, distracted by the glitter of technology and the lure of buried insights. The cast of characters includes the agency head [city official? elected official?...
In their session at @ThingsExpo, Shyam Varan Nath, Principal Architect at GE, and Ibrahim Gokcen, who leads GE's advanced IoT analytics, focused on the Internet of Things / Industrial Internet and how to make it operational for business end-users. Learn about the challenges posed by machine and sensor data and how to marry it with enterprise data. They also discussed the tips and tricks to provide the Industrial Internet as an end-user consumable service using Big Data Analytics and Industrial C...