Welcome!

Weblogic Authors: Yeshim Deniz, Elizabeth White, Michael Meiner, Michael Bushong, Avi Rosenthal

Related Topics: @CloudExpo, Java IoT, Microservices Expo, Containers Expo Blog

@CloudExpo: Blog Post

High Availability, Fault Tolerance and Disaster Recovery in AWS

Introducing elastic cloud computing for Disaster Recovery, Fault Tolerance and High Availability

Amazon Web Services – Disaster Recovery, High Availability and Fault Tolerance

Abbreviations used:

  • AWS - Amazon Web Services
  • AMI - Amazon Machine Instance
  • DR - Disaster Recovery
  • FT - Fault Tolerance
  • HA - High Availability

Non-technical introduction.
H
igh Availability and Fault Tolerance – the requirement that a computer application be seemlessly available to users without interruption, literally “no (or very little) fault will be tolerated”. In simple speak, this means that I am able to use a computer application even though in the background there may be outages, for example hardware failure, network congestion or maximum CPU utilization.  The application is “highly available”, it  is available “(almost) all the time.”

Disaster Recovery – what it takes for your organization to recover from a computer disaster and be operational again. Simple example: suppose a hard-drive fails, do you need a duplicate hard-drive with an identical copy of the data available  within micro-seconds? Or can your application be unavailable to end-users while a new hard-drive is installed and data restored from a backup, knowing that there will be data missing between the time of the last backup and the failure of the hard-drive?

Organizations such as an “online auction company” and a “major search engine” cannot tolerate down-time nor data loss. Your personal computer, though, can likely tolerate some downtime and even data loss. Sometimes DR is automatic, when the primary hardware/software fails, the secondary automatically takes over; other times DR requires manual intervention.  Whichever you configure, depends on your tolerance for downtime. When considering FT and DR, there are two important terms:

  • Recovery Time Objective: how long it takes your organization to recover from an outage.
  • Recovery Point Objective:how much data can you afford to lose.

What does Fault Tolerance, High Availability and Disaster Recovery cost?
Organizations that require almost 100% availability and fractional if any data loss,  build redundant datacenters. Entire datacenters with hardware and software and identical copies of the appliction and data. Sometimes these extra datacenter(s) are used to offload traffic from the primary datacenter(s) during times of peak usage. Example, during the November/December shopping season or March/April tax season, companies like an “online auction company” and an “online tax company”, will offload some traffic from their primary servers to secondary servers. Other times, these extra datacenter(s) are simply sitting idle waiting for a disaster to occur at the primary datacenter. Hardware, software, electric power, air conditioning,  building rent and physical security all “just in case” or “when we need it. The invesment in the secondary datacenter(s) is up-front capital expenditure. Secondary datacenters are expensive for computing power that is often idle!

Introducing elastic cloud computing for Disaster Recovery, Fault Tolerance and High Availability.
What is an elastic band? A thin strip of rubber that stretches or contracts. If I need to bind three DVDs together before loaning them to a friend, the elastic band may stretch to perhaps 50% of capacity. If I  am loaning six or seven DVDs, the elastic band may stretch to maximum capacity, but either way I only need one elastic band, I don’t need to buy two. This concept illustrates the elasticity of cloud computing:  use and pay for computing services only when you need it.

In my above example, when tax season begins, “online tax company” can request and purchase computing services from a provider, such as Amazon Web Services,  and then at the end of tax season cease using and paying for those computing services. Thus “online tax company” can provide a HA tax processing service to their customers, because their primary datacenter(s) will not be overloaded. “Online tax company” will automatically scale out to a cloud provider such as Amazon as needed.  Secondly, the extra computing services provide FT, in case there is a disaster at their physical site during peak tax season.

High Availability, Fault Tolerance and Disaster Recovery in the Cloud
What about an organization that does not own a physical datacenter, but instead runs their entire operation in the cloud. How does their cloud provider provide FT, HA and DR? How does this compare to HA, FT and DR in physical datacenters?

What follows is a precis of two white-papers from Amazon Web Services, Building Fault Tolerant Applications on AWS and Using AWS for Disaster Recovery

This table is  a technical overview of AWS’s FT, HA and DR features compared to a physical environment:

Failure or fault

Physical server

Amazon Web Services

Server failure

To provide fault tolerance I need to have a second server on standby, with an identical copy of the application. I also need to re-direct traffic to the second server by changing the IP address of the second server to the IP address of the primary server.

I launch a new instance of my failed AMI from an AMI template using a script, an API call or the web console. I then map my elastic IP address to the new instance.  AWS CloudFormation allows me to create a collection of AMIs and resources.

Backups for FT

Physical backups often use tape or other mediume for duplication often stored offsite. Backup and Restore can be time consuming.

AWS backups are snapshots of an AMI that can be easily restored using command line or the web console in near instantaneous time.

Storage

If a physical server uses Network Attached Storage, the data is preserved if the server fails. If the server uses an internal drive, the drive is unavailable and potentially lost if the server fails.

Elastic Block Storage is separate from the AMI and persists even if the AMI does not. EBS is built on highly redundant storage that has a failure rate of 0.1 to 0.5% compared to 4% for a standard hard-drive.

IP addressing

An IP address is bound to a physical server and manual configuration is required to modify the IP address of a server.

AWS IP addresses are bound to an AWS account and separate from the AMI. They can be dynamically associated or disassociated from an AMI.

Scale/Growth for HA

To extend the capacity, while maintaining High Availability, of an application running on physical servers, I have to purchase more hardware, rackspace, electrical power and cooling. When I have excess capacity, these servers are idle, consume space, power and waste money.

To extend the capacity of an application running in an AWS cloud, I can use autoscaling which automatically adds AMIs to my capacity based on rules. Similary, I can terminate instances when no longer needed. This also allows me to refresh instances if they degrade.

Load Balancing for HA and FT

A physical load balancer balances traffic across known physical servers. It can detect a server is overloaded and direct traffic to other less utilized servers.

Elastic Load Balancing distributes traffic across AMIs, detects which AMIs may be less responsive and redirects traffic away from them until they are restored.

Multiple Geographies for HA

Physical servers are stored in datacenters around the world to provide HA.

AWS is distributed across geographic regions with Availability Zones within each region to provide HA.

Guaranteed Failover and FT

An organization that purchases its own physical servers is guaranteed failover to those servers.

An AWS customer can purchase Reserved AMIs that are guaranteed to the customer, regardless of what overall load AWS  may experience.

An AWS customer can purchase Reserved AMIs that are guaranteed to the customer, regardless of what overall load AWS  may experience.

I can maintain a physical data center and use the AWS as needed. There are four configuration options.

  1. AWS as backup - I can back up my physical environment to AWS using DirectConnect or AWS import/export, thus using AWS as for backup.
  2. Minimal AWS - In this scenario I have core services permanently running in AWS, for example copies of my data/databases. In case of failure of my physical datacenter, I need to startup AMIs that contain my applications that then connect to my redundant datastores in AWS and modify DNS settings to route traffic to AWS.
  3. Partial AWS - In this scenario I have a complete duplicate of my services permanently running in AWS, but on a minimal number of AMIs. In case of failure of my physical datacenter, I scale up the configuration of my AMIs to cope with the increased load.
  4. Complete AWS - In this scenario I have a complete duplicated configuration of my physical datacenter in AWS. I can use weighted 53 DNS service from AWS to redirect traffic, application logic to use theAWS datastores and EC2 auto-scaling to grow capacity within AWS.

More Stories By Jonathan Gershater

Jonathan Gershater has lived and worked in Silicon Valley since 1996, primarily doing system and sales engineering specializing in: Web Applications, Identity and Security. At Red Hat, he provides Technical Marketing for Virtualization and Cloud. Prior to joining Red Hat, Jonathan worked at 3Com, Entrust (by acquisition) two startups, Sun Microsystems and Trend Micro.

(The views expressed in this blog are entirely mine and do not represent my employer - Jonathan).

@ThingsExpo Stories
Organizations planning enterprise data center consolidation and modernization projects are faced with a challenging, costly reality. Requirements to deploy modern, cloud-native applications simultaneously with traditional client/server applications are almost impossible to achieve with hardware-centric enterprise infrastructure. Compute and network infrastructure are fast moving down a software-defined path, but storage has been a laggard. Until now.
Digital Transformation is much more than a buzzword. The radical shift to digital mechanisms for almost every process is evident across all industries and verticals. This is often especially true in financial services, where the legacy environment is many times unable to keep up with the rapidly shifting demands of the consumer. The constant pressure to provide complete, omnichannel delivery of customer-facing solutions to meet both regulatory and customer demands is putting enormous pressure on...
The best way to leverage your CloudEXPO | DXWorldEXPO presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering CloudEXPO | DXWorldEXPO will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at CloudEXPO. Product announcements during our show provide your company with the most reach through our targeted audienc...
DXWorldEXPO LLC announced today that All in Mobile, a mobile app development company from Poland, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. All In Mobile is a mobile app development company from Poland. Since 2014, they maintain passion for developing mobile applications for enterprises and startups worldwide.
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
JETRO showcased Japan Digital Transformation Pavilion at SYS-CON's 21st International Cloud Expo® at the Santa Clara Convention Center in Santa Clara, CA. The Japan External Trade Organization (JETRO) is a non-profit organization that provides business support services to companies expanding to Japan. With the support of JETRO's dedicated staff, clients can incorporate their business; receive visa, immigration, and HR support; find dedicated office space; identify local government subsidies; get...
The current age of digital transformation means that IT organizations must adapt their toolset to cover all digital experiences, beyond just the end users’. Today’s businesses can no longer focus solely on the digital interactions they manage with employees or customers; they must now contend with non-traditional factors. Whether it's the power of brand to make or break a company, the need to monitor across all locations 24/7, or the ability to proactively resolve issues, companies must adapt to...
"We view the cloud not as a specific technology but as a way of doing business and that way of doing business is transforming the way software, infrastructure and services are being delivered to business," explained Matthew Rosen, CEO and Director at Fusion, in this SYS-CON.tv interview at 18th Cloud Expo (http://www.CloudComputingExpo.com), held June 7-9 at the Javits Center in New York City, NY.
DXWorldEXPO LLC announced today that the upcoming DXWorldEXPO | CloudEXPO New York event will feature 10 companies from Poland to participate at the "Poland Digital Transformation Pavilion" on November 12-13, 2018.
As data explodes in quantity, importance and from new sources, the need for managing and protecting data residing across physical, virtual, and cloud environments grow with it. Managing data includes protecting it, indexing and classifying it for true, long-term management, compliance and E-Discovery. Commvault can ensure this with a single pane of glass solution – whether in a private cloud, a Service Provider delivered public cloud or a hybrid cloud environment – across the heterogeneous enter...
DXWorldEXPO LLC announced today that ICC-USA, a computer systems integrator and server manufacturing company focused on developing products and product appliances, will exhibit at the 22nd International CloudEXPO | DXWorldEXPO. DXWordEXPO New York 2018, colocated with CloudEXPO New York 2018 will be held November 11-13, 2018, in New York City. ICC is a computer systems integrator and server manufacturing company focused on developing products and product appliances to meet a wide range of ...
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 smart...
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...
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
Headquartered in Plainsboro, NJ, Synametrics Technologies has provided IT professionals and computer systems developers since 1997. Based on the success of their initial product offerings (WinSQL and DeltaCopy), the company continues to create and hone innovative products that help its customers get more from their computer applications, databases and infrastructure. To date, over one million users around the world have chosen Synametrics solutions to help power their accelerated business or per...
Dion Hinchcliffe is an internationally recognized digital expert, bestselling book author, frequent keynote speaker, analyst, futurist, and transformation expert based in Washington, DC. He is currently Chief Strategy Officer at the industry-leading digital strategy and online community solutions firm, 7Summits.
We are seeing a major migration of enterprises applications to the cloud. As cloud and business use of real time applications accelerate, legacy networks are no longer able to architecturally support cloud adoption and deliver the performance and security required by highly distributed enterprises. These outdated solutions have become more costly and complicated to implement, install, manage, and maintain.SD-WAN offers unlimited capabilities for accessing the benefits of the cloud and Internet. ...
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 ...
Bill Schmarzo, author of "Big Data: Understanding How Data Powers Big Business" and "Big Data MBA: Driving Business Strategies with Data Science," is responsible for setting the strategy and defining the Big Data service offerings and capabilities for EMC Global Services Big Data Practice. As the CTO for the Big Data Practice, he is responsible for working with organizations to help them identify where and how to start their big data journeys. He's written several white papers, is an avid blogge...
Founded in 2000, Chetu Inc. is a global provider of customized software development solutions and IT staff augmentation services for software technology providers. By providing clients with unparalleled niche technology expertise and industry experience, Chetu has become the premiere long-term, back-end software development partner for start-ups, SMBs, and Fortune 500 companies. Chetu is headquartered in Plantation, Florida, with thirteen offices throughout the U.S. and abroad.