Welcome!

IoT User Interface Authors: Elizabeth White, Donald Meyer, Liz McMillan, AppDynamics Blog, Yakov Fain

Related Topics: @CloudExpo, Microservices Expo, Microsoft Cloud, Containers Expo Blog, IoT User Interface, Apache

@CloudExpo: Blog Feed Post

Load Balancing 101: Scale versus Fail

Elasticity is a design pattern for scalability, not necessarily failability.

One of the phrases you hear associated with cloud computing is "architecting for failure." Rather than build in a lot of hardware-level redundancy – power, disk, network, etc… – the idea is that you expect it to fail and can simply replace the application (which is what you care about anyway, right?) with a clone running on the same cheap hardware somewhere else in the data center.

Awesome idea, right?

But when it comes down to it, cloud computing environments are architected for scale, not fail.

lb-scale-vs-fail

SCALE versus FAIL

Most enterprise-class data centers have been architected with failure in mind; we call these high-availability (HA) architectures. The goal is to ensure that if any element in the data path fails that another can almost immediately take its place. Within a hardware platform, this implies dual power supplies, a high RAID level, and lights-out management. At the network and higher level, this requires redundant network elements – from load balancers to switches to routers to firewalls to servers, all elements must be duplicated to ensure a (near) immediate failover in the event of a failure. This generally requires configurations and support for floating (shared) IP addresses across redundant elements, allowing for immediate redirection upon detection of a failure upstream.

At the application/server tier, the shared address concept is still applied but it is done so at the load balancing layer, where VIP (virtual IP addresses) act as a virtual instance of the application. A primary node (server) is designated that is active with a secondary being designated as the "backup" instance which remains idle in "standby" mode*.

If the primary instance fails – whether due to hardware or software or network failure – the secondary immediately becomes active, and continuity of service is assured by virtue of the fact that existing sessions are managed by the load balancing service, not the server. In the event a network element fails, continuity (high-availability) is achieved due to the mirroring (replication) of those same sessions between the active (primary) and standby (secondary) elements. inoneminute1

Is it perfect? No, but it does provide sub-second response to failure, which means very high levels of availability (or as I like to call it, failability).

That's architected for "FAIL".

Now, most cloud computing environments are architected not with failure in mind but with scale in mind – that is, they are designed to enable elasticity (scale out, scale in) that is, in part, based on the ability to rapidly provision the resources required.

A load balancing instance is required and it works in much the same way as a high-availability architecture (minus the redundancy). The load balancing service acts as the virtual application, with at least one instance behind it. As demand increases, new instances are provisioned and added to the service to ensure that performance and availability are not adversely impacted. When this process is also capable of scaling back in by automatically eliminating instances when demand contracts it's called "elasticity".

If the only instance available fails, this architecture is not going to provide high availability of the application because it takes time to launch an instance to replace it. Even if there are ten active instances and one fails, performance and/or availability for some clients may be impacted because, as noted already, it takes time to launch an instance to replace it.

Similarly, if an upstream element fails, such as the load balancing service, availability may be adversely impacted – because it takes time to replace it.

But when considering how well the system responds to changes in demand for resources, it works well. That's scalability.

That's architected for "SCALE".

SCALE and FAIL are NOT INTERCHANGEABLE

These two are not interchangeable, they cannot be conflated with the expectation that either architecture is able to meet both goals equally well. They are designed to resolve two different problems.

The two can be combined to achieve a scalable, high-availability architecture where redundancy is used to assure availability while elasticity is leveraged to realize scale while reducing the time to provision and investment costs by implementing a virtual, flexible resource model.

It's important to understand the difference in these architectures especially when looking to public cloud as an option because they are primarily designed to enable scalability, not failability. If you absolutely need failability, you'll need to do some legwork of your own (scripts or manual intervention – perhaps both) to ensure a more seamless failover in the event of failure or specifically seek out cloud providers that recognize the inherent differences between the two architectures and support either the one you need, or both.

Relying on an elastic architecture to provide high-availability – or vice-versa – is likely to end poorly.


Downtime cost source: IT Downtime Costs $26.5 Billion In Lost Revenue

Read the original blog entry...

More Stories By Lori MacVittie

Lori MacVittie is responsible for education and evangelism of application services available across F5’s entire product suite. Her role includes authorship of technical materials and participation in a number of community-based forums and industry standards organizations, among other efforts. MacVittie has extensive programming experience as an application architect, as well as network and systems development and administration expertise. Prior to joining F5, MacVittie was an award-winning Senior Technology Editor at Network Computing Magazine, where she conducted product research and evaluation focused on integration with application and network architectures, and authored articles on a variety of topics aimed at IT professionals. Her most recent area of focus included SOA-related products and architectures. She holds a B.S. in Information and Computing Science from the University of Wisconsin at Green Bay, and an M.S. in Computer Science from Nova Southeastern University.

@CloudExpo Stories
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, wh...
The 19th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, 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 y...
SYS-CON Events announced today that MangoApps will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. MangoApps provides modern company intranets and team collaboration software, allowing workers to stay connected and productive from anywhere in the world and from any device. For more information, please visit https://www.mangoapps.com/.
Many banks and financial institutions are experimenting with containers in development environments, but when will they move into production? Containers are seen as the key to achieving the ultimate in information technology flexibility and agility. Containers work on both public and private clouds, and make it easy to build and deploy applications. The challenge for regulated industries is the cost and complexity of container security compliance. VM security compliance is already challenging, ...
Internet of @ThingsExpo, taking place November 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 19th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo New York Call for Papers is now open.
SYS-CON Events announced today that ContentMX, the marketing technology and services company with a singular mission to increase engagement and drive more conversations for enterprise, channel and SMB technology marketers, has been named “Sponsor & Exhibitor Lounge Sponsor” of SYS-CON's 18th Cloud Expo, which will take place on June 7-9, 2016, at the Javits Center in New York City, New York. “CloudExpo is a great opportunity to start a conversation with new prospects, but what happens after the...
The IoT is changing the way enterprises conduct business. In his session at @ThingsExpo, Eric Hoffman, Vice President at EastBanc Technologies, discuss how businesses can gain an edge over competitors by empowering consumers to take control through IoT. We'll cite examples such as a Washington, D.C.-based sports club that leveraged IoT and the cloud to develop a comprehensive booking system. He'll also highlight how IoT can revitalize and restore outdated business models, making them profitable...
Designing IoT applications is complex, but deploying them in a scalable fashion is even more complex. A scalable, API first IaaS cloud is a good start, but in order to understand the various components specific to deploying IoT applications, one needs to understand the architecture of these applications and figure out how to scale these components independently. In his session at @ThingsExpo, Nara Rajagopalan is CEO of Accelerite, will discuss the fundamental architecture of IoT applications, ...
In his session at 18th Cloud Expo, Bruce Swann, Senior Product Marketing Manager at Adobe, will discuss how the Adobe Marketing Cloud can help marketers embrace opportunities for personalized, relevant and real-time customer engagement across offline (direct mail, point of sale, call center) and digital (email, website, SMS, mobile apps, social networks, connected objects). Bruce Swann has more than 15 years of experience working with digital marketing disciplines like web analytics, social med...
SYS-CON Events announced today that Enzu, a leading provider of cloud hosting solutions, will exhibit at SYS-CON's 18th International Cloud Expo®, which will take place on June 7-9, 2016, at the Javits Center in New York City, NY. Enzu’s mission is to be the leading provider of enterprise cloud solutions worldwide. Enzu enables online businesses to use its IT infrastructure to their competitive advantage. By offering a suite of proven hosting and management services, Enzu wants companies to foc...
Customer experience has become a competitive differentiator for companies, and it’s imperative that brands seamlessly connect the customer journey across all platforms. With the continued explosion of IoT, join us for a look at how to build a winning digital foundation in the connected era – today and in the future. In his session at @ThingsExpo, Chris Nguyen, Group Product Marketing Manager at Adobe, will discuss how to successfully leverage mobile, rapidly deploy content, capture real-time d...
IoT generates lots of temporal data. But how do you unlock its value? How do you coordinate the diverse moving parts that must come together when developing your IoT product? What are the key challenges addressed by Data as a Service? How does cloud computing underlie and connect the notions of Digital and DevOps What is the impact of the API economy? What is the business imperative for Cognitive Computing? Get all these questions and hundreds more like them answered at the 18th Cloud Expo...
The cloud market growth today is largely in public clouds. While there is a lot of spend in IT departments in virtualization, these aren’t yet translating into a true “cloud” experience within the enterprise. What is stopping the growth of the “private cloud” market? In his general session at 18th Cloud Expo, Nara Rajagopalan, CEO of Accelerite, will explore the challenges in deploying, managing, and getting adoption for a private cloud within an enterprise. What are the key differences betwee...
As cloud and storage projections continue to rise, the number of organizations moving to the cloud is escalating and it is clear cloud storage is here to stay. However, is it secure? Data is the lifeblood for government entities, countries, cloud service providers and enterprises alike and losing or exposing that data can have disastrous results. There are new concepts for data storage on the horizon that will deliver secure solutions for storing and moving sensitive data around the world. ...
Enterprise networks are complex. Moreover, they were designed and deployed to meet a specific set of business requirements at a specific point in time. But, the adoption of cloud services, new business applications and intensifying security policies, among other factors, require IT organizations to continuously deploy configuration changes. Therefore, enterprises are looking for better ways to automate the management of their networks while still leveraging existing capabilities, optimizing perf...
What a difference a year makes. Organizations aren’t just talking about IoT possibilities, it is now baked into their core business strategy. With IoT, billions of devices generating data from different companies on different networks around the globe need to interact. From efficiency to better customer insights to completely new business models, IoT will turn traditional business models upside down. In the new customer-centric age, the key to success is delivering critical services and apps wit...
The essence of data analysis involves setting up data pipelines that consist of several operations that are chained together – starting from data collection, data quality checks, data integration, data analysis and data visualization (including the setting up of interaction paths in that visualization). In our opinion, the challenges stem from the technology diversity at each stage of the data pipeline as well as the lack of process around the analysis.
Cloud-based NCLC (No-code/low code) application builder platforms empower everyone in the organization to quickly build applications and executable processes that broaden access, deepen collaboration, and enhance transparency for all team members. Line of business owners (LOBO) and operations managers know best their part of the business and their processes. IT departments are beginning to leverage NCLC platforms to empower and enable LOBOs to lead the innovation, transform the organization, an...
@DevOpsSummit taking place June 7-9, 2016 at Javits Center, New York City, and Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 18th International @CloudExpo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world.
SYS-CON Events announced today the Docker Meets Kubernetes – Intro into the Kubernetes World, being held June 9, 2016, in conjunction with 18th Cloud Expo | @ThingsExpo, at the Javits Center in New York, NY. Register for 'Docker Meets Kubernetes Workshop' Here! This workshop led by Sebastian Scheele, co-founder of Loodse, introduces participants to Kubernetes (container orchestration). Through a combination of instructor-led presentations, demonstrations, and hands-on labs, participants learn ...