Click here to close now.

Welcome!

Cloud Expo Authors: Max Katz, AppDynamics Blog, Plutora Blog, Carmen Gonzalez, Cloud Best Practices Network

Related Topics: Cloud Expo

Cloud Expo: 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.

@CloudExpo Stories
PubNub on Monday has announced that it is partnering with IBM to bring its sophisticated real-time data streaming and messaging capabilities to Bluemix, IBM’s cloud development platform. “Today’s app and connected devices require an always-on connection, but building a secure, scalable solution from the ground up is time consuming, resource intensive, and error-prone,” said Todd Greene, CEO of PubNub. “PubNub enables web, mobile and IoT developers building apps on IBM Bluemix to quickly add sc...
Business and IT leaders today need better application delivery capabilities to support critical new innovation. But how often do you hear objections to improving application delivery like, “I can harden it against attack, but not on this timeline”; “I can make it better, but it will cost more”; “I can deliver faster, but not with these specs”; or “I can stay strong on cost control, but quality will suffer”? In the new application economy, these tradeoffs are no longer acceptable. Customers will ...
The Internet of Things (IoT) is rapidly in the process of breaking from its heretofore relatively obscure enterprise applications (such as plant floor control and supply chain management) and going mainstream into the consumer space. More and more creative folks are interconnecting everyday products such as household items, mobile devices, appliances and cars, and unleashing new and imaginative scenarios. We are seeing a lot of excitement around applications in home automation, personal fitness,...
Data-intensive companies that strive to gain insights from data using Big Data analytics tools can gain tremendous competitive advantage by deploying data-centric storage. Organizations generate large volumes of data, the vast majority of which is unstructured. As the volume and velocity of this unstructured data increases, the costs, risks and usability challenges associated with managing the unstructured data (regardless of file type, size or device) increases simultaneously, including end-to-...
Red Hat has launched the Red Hat Cloud Innovation Practice, a new global team of experts that will assist companies with more quickly on-ramping to the cloud. They will do this by providing solutions and services such as validated designs with reference architectures and agile methodology consulting, training, and support. The Red Hat Cloud Innovation Practice is born out of the integration of technology and engineering expertise gained through the company’s 2014 acquisitions of leading Ceph s...
The excitement around the possibilities enabled by Big Data is being tempered by the daunting task of feeding the analytics engines with high quality data on a continuous basis. As the once distinct fields of data integration and data management increasingly converge, cloud-based data solutions providers have emerged that can buffer your organization from the complexities of this continuous data cleansing and management so that you’re free to focus on the end goal: actionable insight.
With several hundred implementations of IoT-enabled solutions in the past 12 months alone, this session will focus on experience over the art of the possible. Many can only imagine the most advanced telematics platform ever deployed, supporting millions of customers, producing tens of thousands events or GBs per trip, and hundreds of TBs per month. With the ability to support a billion sensor events per second, over 30PB of warm data for analytics, and hundreds of PBs for an data analytics arc...
The Internet of Things (IoT) is causing data centers to become radically decentralized and atomized within a new paradigm known as “fog computing.” To support IoT applications, such as connected cars and smart grids, data centers' core functions will be decentralized out to the network's edges and endpoints (aka “fogs”). As this trend takes hold, Big Data analytics platforms will focus on high-volume log analysis (aka “logs”) and rely heavily on cognitive-computing algorithms (aka “cogs”) to mak...
The free version of KEMP Technologies' LoadMaster™ application load balancer is now available for unlimited use, making it easy for IT developers and open source technology users to benefit from all the features of a full commercial-grade product at no cost. It can be downloaded at FreeLoadBalancer.com. Load balancing, security and traffic optimization are all key enablers for application performance and functionality. Without these, application services will not perform as expected or have the...
The speed of product development has increased massively in the past 10 years. At the same time our formal secure development and SDL methodologies have fallen behind. This forces product developers to choose between rapid release times and security. In his session at DevOps Summit, Michael Murray, Director of Cyber Security Consulting and Assessment at GE Healthcare, examined the problems and presented some solutions for moving security into the DevOps lifecycle to ensure that we get fast AND ...
The Workspace-as-a-Service (WaaS) market will grow to $6.4B by 2018. In his session at 16th Cloud Expo, Seth Bostock, CEO of IndependenceIT, will begin by walking the audience through the evolution of Workspace as-a-Service, where it is now vs. where it going. To look beyond the desktop we must understand exactly what WaaS is, who the users are, and where it is going in the future. IT departments, ISVs and service providers must look to workflow and automation capabilities to adapt to growing ...
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...
The Internet of Things (IoT) promises to evolve the way the world does business; however, understanding how to apply it to your company can be a mystery. Most people struggle with understanding the potential business uses or tend to get caught up in the technology, resulting in solutions that fail to meet even minimum business goals. In his session at @ThingsExpo, Jesse Shiah, CEO / President / Co-Founder of AgilePoint Inc., showed what is needed to leverage the IoT to transform your business. ...
Hadoop as a Service (as offered by handful of niche vendors now) is a cloud computing solution that makes medium and large-scale data processing accessible, easy, fast and inexpensive. In his session at Big Data Expo, Kumar Ramamurthy, Vice President and Chief Technologist, EIM & Big Data, at Virtusa, will discuss how this is achieved by eliminating the operational challenges of running Hadoop, so one can focus on business growth. The fragmented Hadoop distribution world and various PaaS soluti...
Advanced Persistent Threats (APTs) are increasing at an unprecedented rate. The threat landscape of today is drastically different than just a few years ago. Attacks are much more organized and sophisticated. They are harder to detect and even harder to anticipate. In the foreseeable future it's going to get a whole lot harder. Everything you know today will change. Keeping up with this changing landscape is already a daunting task. Your organization needs to use the latest tools, methods and ex...
In his session at DevOps Summit, Tapabrata Pal, Director of Enterprise Architecture at Capital One, will tell a story about how Capital One has embraced Agile and DevOps Security practices across the Enterprise – driven by Enterprise Architecture; bringing in Development, Operations and Information Security organizations together. Capital Ones DevOpsSec practice is based upon three "pillars" – Shift-Left, Automate Everything, Dashboard Everything. Within about three years, from 100% waterfall, C...
Disruptive macro trends in technology are impacting and dramatically changing the "art of the possible" relative to supply chain management practices through the innovative use of IoT, cloud, machine learning and Big Data to enable connected ecosystems of engagement. Enterprise informatics can now move beyond point solutions that merely monitor the past and implement integrated enterprise fabrics that enable end-to-end supply chain visibility to improve customer service delivery and optimize sup...
Even as cloud and managed services grow increasingly central to business strategy and performance, challenges remain. The biggest sticking point for companies seeking to capitalize on the cloud is data security. Keeping data safe is an issue in any computing environment, and it has been a focus since the earliest days of the cloud revolution. Understandably so: a lot can go wrong when you allow valuable information to live outside the firewall. Recent revelations about government snooping, along...
SYS-CON Events announced today that Dyn, the worldwide leader in Internet Performance, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Dyn is a cloud-based Internet Performance company. Dyn helps companies monitor, control, and optimize online infrastructure for an exceptional end-user experience. Through a world-class network and unrivaled, objective intelligence into Internet conditions, Dyn ensures...
VictorOps is making on-call suck less with the only collaborative alert management platform on the market. With easy on-call scheduling management, a real-time incident timeline that gives you contextual relevance around your alerts and powerful reporting features that make post-mortems more effective, VictorOps helps your IT/DevOps team solve problems faster.