Welcome!

Linux Containers Authors: Liz McMillan, Elizabeth White, Pat Romanski, Yeshim Deniz, Stackify Blog

Related Topics: @CloudExpo

@CloudExpo: Blog Feed Post

Amazon Makes the Cloud Sticky

Stateless applications may be the long term answer to scalability of applications in the cloud

Stateless applications may be the long term answer to scalability of applications in the cloud, but until then, we need a solution like sticky sessions (persistence)

Amazon recently introduced “stickiness” to its ELB (Elastic Load Balancing) offering. I’ve written a bit about “stickiness”, a.k.a. what we’ve called persistence for oh, nearly ten years now, before so I won’t reiterate again but to say, “it’s about time.” A description of why sticky sessions is necessary was offered in the AWS blog announcing the new feature:

blockquote Up until now each Load balancer had the freedom to forward each incoming HTTP or TCP request to any of the EC2 instances under its purview. This resulted in a reasonably even load on each instance, but it also meant that each instance would have to retrieve, manipulate, and store session data for each request without any possible benefit from locality of reference.

-- New Elastic Load Balancing Feature: Sticky Sessions

What the author is really trying to say is that without “sticky sessions” ELB breaks applications because it does not honor state. Remember that most web applications today rely upon state (session) to store quite a bit of application and user specific data that’s necessary for the application to behave properly. When a load balancer distributes requests across instances without consideration for where that state (session) is stored, the application behavior can become erratic and unpredictable. Hence the need for “stickiness”.


WHY is THIS IMPORTANT?

In addition to web applications relying heavily on state, so too do the APIs used to integrate them with each other and with other Web 2.0 applications like Twitter and Facebook and <insert favorite app here>. So called “REST” APIs today aren’t really REST. We know that. They’re RESTful but they aren’t truly REST according to the definition laid down primarily because they aren’t stateless. It turns out state and application development is not just a concern of application architects and developers these days, but of infrastructure vendors, pundits, analysts, and anyone interested in the evolution of cloud computing and a truly distributed, portable model of application deployment and delivery.

State is, to sum up the viewpoint, a sticking point.

blockquote_thumb1 As I see it there are two major types of workloads that a organisation is going to want to run on an external Cloud. The new breed which are built for the new Cloud model. These will scale out, be light weight, stateless and fit perfectly with a consumption based model. Run a few small VM's, with low RAM and CPU consumption, as demand increases the application dynamically scales itself out to meet demand, whether that be user generated or application generated, such as a month end processing run. -- Rodney Haywood: The Granularity of On-Demand Cloud - Today vs Tomorrow

Stateless. It was something we heard sprinkled throughout conversations at CloudConnect, as well. The best “workload” to run in a cloud is a “stateless” web application. Developers have to change the way they develop applications – they must go stateless. Portability requires (read: would be easier to implement) if applications were stateless.

That’s easy to say but a lot more difficult to implement.


THE NECESSARY EVIL of STATE

The first greatest and most useful hack involving the web was enabling state for HTTP. Prior to the advent of sessions and state, the web was pretty much like interacting with a technicolor mainframe application. Folks even referred to “pages” as “screens”, in reference to the way in which one statically walked through big iron applications in a very linear and image uncompromising fashion. Made a mistake? Not acceptable. “Back” and “previous” were foreign concepts. You had to effectively start over and change the existing transaction, which had likely already been committed to the database (assuming there was one). Sessions provided the ability to allow for mistakes and to allow better navigation options within an application. That’s because the transaction wasn’t committed to the database until the user was ready. Data entered in “step 1” could be modified after “step 4” with little effort on the part of the developer. AJAX has made this even easier, as it makes editing data after the fact (or during the process) able to directly transact with the database on a very granular, i.e. field or column, level basis.

Now, if developers chose to do so, they could certainly employ the ability of web and application servers to leverage a shared session database to remove this sometimes onerous requirement. This would certainly free the infrastructure from needing to worry about persisting connections and make scalable architectures simpler to implement, but it would not make the application stateless. We’d just be moving where the “state” is stored from the web/application server to a database. But that, REST purists would argue, is still not a “stateless” application programming model, which most decidedly states that all “session” data (i.e. state) should be stored on the client. Not in cookies, either, but in the client – as in enclosed in forms or query parameters or in JavaScript object models. From a performance perspective this is not optimal, either, as a “shared” session architecture necessarily requires a heavier load on the data store in which the session is stored. For every request the “state” must be retrieved, which in a cloud computing environment may incur bandwidth utilization and session database instance/row/<insert billing model here> charges.

Storing all state on the client would have an impact on just about the entire infrastructure stack and would also likely negatively impact many mobile applications, an increasingly popular client model that should not be ignored in decisions regarding the amount of data being exchanged between client and server.

Thus it is that “stateless” applications are unlikely to become the norm for some time (if ever). State is a necessary “evil”, though it’s “evilness” is certainly, like beauty, in the eye of the developer. Assuming that stateful applications remain the norm in the cloud means that load balancing services in those clouds must necessarily support the notion of persistence (stickiness) to ensure applications don’t break upon deployment. This also results in making it easier for organizations to migrate non-native “cloud” applications to EC2, because there’s no requirement that the application be rewritten in order to run properly (taking into consideration state/session) in a scalable environment.

Thus, Amazon introducing “sticky sessions” to ELB is a Very Good Thing.

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.

@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.
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.
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...
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 ...
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...
@DevOpsSummit at Cloud Expo, taking place November 12-13 in New York City, NY, is co-located with 22nd international CloudEXPO | first international DXWorldEXPO and will feature technical sessions from a rock star conference faculty and the leading industry players in the world.
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.
In his keynote at 19th Cloud Expo, Sheng Liang, co-founder and CEO of Rancher Labs, discussed the technological advances and new business opportunities created by the rapid adoption of containers. With the success of Amazon Web Services (AWS) and various open source technologies used to build private clouds, cloud computing has become an essential component of IT strategy. However, users continue to face challenges in implementing clouds, as older technologies evolve and newer ones like Docker c...
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 ...
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 ...
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. ...
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.
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.
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...
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...
Charles Araujo is an industry analyst, internationally recognized authority on the Digital Enterprise and author of The Quantum Age of IT: Why Everything You Know About IT is About to Change. As Principal Analyst with Intellyx, he writes, speaks and advises organizations on how to navigate through this time of disruption. He is also the founder of The Institute for Digital Transformation and a sought after keynote speaker. He has been a regular contributor to both InformationWeek and CIO Insight...
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
Michael Maximilien, better known as max or Dr. Max, is a computer scientist with IBM. At IBM Research Triangle Park, he was a principal engineer for the worldwide industry point-of-sale standard: JavaPOS. At IBM Research, some highlights include pioneering research on semantic Web services, mashups, and cloud computing, and platform-as-a-service. He joined the IBM Cloud Labs in 2014 and works closely with Pivotal Inc., to help make the Cloud Found the best PaaS.