|By Lori MacVittie||
|November 16, 2012 10:00 AM EST||
Choice of load balancing algorithms is critical to ensuring consistent and acceptable performance
One of the primary reasons folks use a Load balancer is scalability with a secondary driver of maintaining performance. We all know the data exists to prove that "seconds matter" and current users of the web have itchy fingers, ready to head for the competition the microsecond they experience any kind of delay.
Similarly, we know that productivity is inherently tied to performance. With more and more critical business functions "webified", the longer it takes to load a page the longer the delay a customer or help desk service representative experiences, reducing the number of calls or customers that can be serviced in any given measurable period.
So performance is paramount, I see no reason to persuade you further to come to that conclusion.
Ensuring performance then is a vital operational directive. One of the ways operations tries to meet that objective is through load balancing. Distributing load ensures available and can be used to offset any latency introduced by increasing capacity (again, I don't think there's anyone who'll argue against the premise that load and performance degradation are inherently tied together).
But just adding a load balancing service isn't enough. The algorithm used to distribute load will invariably impact performance – for better or for worse.
Consider the industry standard "fastest response time" algorithm. This algorithm distributes load based on the historical performance of each instance in the pool (farm). On the surface, this seems like a good choice. After all, what you want is the fastest response time, so why not base load balancing decisions on the metric against which you are going to be measured?
The answer is simple: "fastest" is relative. With very light load on a pool of, say, three servers, "fastest" might mean sub-second responses. But as load increases and performance decreases, "fastest" might start creeping up into the seconds – if not more. Sure, you're still automagically choosing the fastest of the three servers, but "fastest" is absolutely relative to the measurements of all three servers.
Thus, "fastest response time" is probably a poor choice if one of your goals is measured in response time to the ultimate customer – unless you combine it with an upper connection limit.
HOW TO USE "FASTEST RESPONSE TIME" ALGORITHMS CORRECTLY
One of the negatives of adopting a cloud computing paradigm with a nearly religious-like zeal is that you buy into the notion that utilization is the most important metric in the data center. You simply do not want to be wasting CPU cycles, because that means you're inefficient and not leveraging cloud to its fullest potential.
Well, horse-puckey. The reality is that 100% utilization and consistently well-performing applications do not go hand in hand. Period. You can have one, but not the other. You're going to have to choose which is more important a measurement – fast applications or full utilization.
In the six years I spent load testing everything from web applications to web application firewalls to load balancers to XML gateways one axiom always, always, remained true:
As load increases performance decreases.
You're welcome to test and retest and retest again to prove that wrong, but good luck. I've never seen performance increase or even stay the same as utilization approaches 100%.
Now, once you accept that reality you can use it to your advantage. You know that performance is going to decrease as load increases, you just don't know at what point the degradation will become unacceptable to your users. So you need to test to find that breaking point. You want to stress the application and measure the degradation, noting the number of concurrent connections at which performance starts to degrade into unacceptable territory. That is your connection limit.
Keep track of that limit (for the application, specifically, because not all applications will have the same limits). When you configure your load balancing service you can now select fastest response time but you also need to input hard connection limits on a per-instance basis. This prevents each instance from passing through the load-performance confluence that causes end-users to start calling up the help desk or sighing "the computer is slow" while on the phone with their customers.
This means testing. Not once, not twice, but at least three runs. Make sure you've found the right load-performance confluence point and write it down. On your hand, in permanent marker.
While cloud computing and virtualization have certainly simplified load balancing services in terms of deployment, it's still up to you to figure out the right settings and configuration options to ensure that your applications are performing with the appropriate levels of "fast".
Leysin American School is an exclusive, private boarding school located in Leysin, Switzerland. Leysin selected an OpenStack-powered, private cloud as a service to manage multiple applications and provide development environments for students across the institution. Seeking to meet rigid data sovereignty and data integrity requirements while offering flexible, on-demand cloud resources to users, Leysin identified OpenStack as the clear choice to round out the school's cloud strategy. Additional...
Nov. 21, 2014 08:45 PM EST Reads: 859
Explosive growth in connected devices. Enormous amounts of data for collection and analysis. Critical use of data for split-second decision making and actionable information. All three are factors in making the Internet of Things a reality. Yet, any one factor would have an IT organization pondering its infrastructure strategy. How should your organization enhance its IT framework to enable an Internet of Things implementation? In his session at Internet of @ThingsExpo, James Kirkland, Chief Ar...
Nov. 21, 2014 08:45 PM EST Reads: 781
The major cloud platforms defy a simple, side-by-side analysis. Each of the major IaaS public-cloud platforms offers their own unique strengths and functionality. Options for on-site private cloud are diverse as well, and must be designed and deployed while taking existing legacy architecture and infrastructure into account. Then the reality is that most enterprises are embarking on a hybrid cloud strategy and programs. In this Power Panel at 15th Cloud Expo (http://www.CloudComputingExpo.com...
Nov. 21, 2014 08:00 PM EST Reads: 1,039
Technology is enabling a new approach to collecting and using data. This approach, commonly referred to as the "Internet of Things" (IoT), enables businesses to use real-time data from all sorts of things including machines, devices and sensors to make better decisions, improve customer service, and lower the risk in the creation of new revenue opportunities. In his General Session at Internet of @ThingsExpo, Dave Wagstaff, Vice President and Chief Architect at BSQUARE Corporation, discuss the ...
Nov. 21, 2014 08:00 PM EST Reads: 1,040
The security devil is always in the details of the attack: the ones you've endured, the ones you prepare yourself to fend off, and the ones that, you fear, will catch you completely unaware and defenseless. The Internet of Things (IoT) is nothing if not an endless proliferation of details. It's the vision of a world in which continuous Internet connectivity and addressability is embedded into a growing range of human artifacts, into the natural world, and even into our smartphones, appliances, a...
Nov. 21, 2014 08:00 PM EST Reads: 894
"BSQUARE is in the business of selling software solutions for smart connected devices. It's obvious that IoT has moved from being a technology to being a fundamental part of business, and in the last 18 months people have said let's figure out how to do it and let's put some focus on it, " explained Dave Wagstaff, VP & Chief Architect, at BSQUARE Corporation, in this SYS-CON.tv interview at @ThingsExpo, held Nov 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Nov. 21, 2014 07:00 PM EST Reads: 922
The 4th International DevOps Summit, co-located with16th International Cloud Expo – being held June 9-11, 2015, at the Javits Center in New York City, NY – announces that its Call for Papers is now 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 world's large...
Nov. 21, 2014 06:45 PM EST Reads: 879
Verizon Enterprise Solutions is simplifying the cloud-purchasing experience for its clients, with the launch of Verizon Cloud Marketplace, a key foundational component of the company's robust ecosystem of enterprise-class technologies. The online storefront will initially feature pre-built cloud-based services from AppDynamics, Hitachi Data Systems, Juniper Networks, PfSense and Tervela. Available globally to enterprises using Verizon Cloud, Verizon Cloud Marketplace provides a one-stop shop fo...
Nov. 21, 2014 05:30 PM EST Reads: 954
Software-driven innovation is becoming a primary approach to how businesses create and deliver new value to customers. A survey of 400 business and IT executives by the IBM Institute for Business Value showed businesses that are more effective at software delivery are also more profitable than their peers nearly 70 percent of the time (1). DevOps provides a way for businesses to remain competitive, applying lean and agile principles to software development to speed the delivery of software that ...
Nov. 20, 2014 11:45 PM EST Reads: 1,314
"Our premise is Docker is not enough. That's not a bad thing - we actually love Docker. At ActiveState all our products are based on open source technology and Docker is an up-and-coming piece of open source technology," explained Bart Copeland, President & CEO of ActiveState Software, in this SYS-CON.tv interview at DevOps Summit at Cloud Expo®, held Nov 4-6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
Nov. 20, 2014 10:30 PM EST Reads: 1,193
DevOps Summit 2015 New York, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that it is now accepting Keynote Proposals. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to wait for long development cycles that produce software that is obsolete...
Nov. 20, 2014 09:00 PM EST Reads: 1,388
What do a firewall and a fortress have in common? They are no longer strong enough to protect the valuables housed inside. Like the walls of an old fortress, the cracks in the firewall are allowing the bad guys to slip in - unannounced and unnoticed. By the time these thieves get in, the damage is already done and the network is already compromised. Intellectual property is easily slipped out the back door leaving no trace of forced entry. If we want to reign in on these cybercriminals, it's hig...
Nov. 20, 2014 07:00 PM EST Reads: 1,109
Infor has announced a new feature Infor CloudSuite™ Aerospace & Defense (A&D) to aid compliance with International Traffic in Arms Regulations (ITAR). The ITAR function will serve as a complementary function for new or existing Infor CloudSuite A&D customers, to facilitate compliance for Infor customers that are creating a US defense article or performing a US defense service and wish to benefit from cloud-services. The ITAR regulation serves to manage handling and access requirements for dat...
Nov. 20, 2014 07:00 PM EST Reads: 1,257
Bit6 today issued a challenge to the technology community implementing Web Real Time Communication (WebRTC). To leap beyond WebRTC’s significant limitations and fully leverage its underlying value to accelerate innovation, application developers need to consider the entire communications ecosystem.
Nov. 20, 2014 04:45 PM EST Reads: 922
The 3rd International @ThingsExpo, co-located with the 16th International Cloud Expo - to be held June 9-11, 2015, at the Javits Center in New York City, NY - announces that it is now accepting Keynote Proposals. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devices - computers, smartphones, tablets, and sensors - connected to th...
Nov. 20, 2014 01:00 PM EST Reads: 1,428
The Internet of Things is not new. Historically, smart businesses have used its basic concept of leveraging data to drive better decision making and have capitalized on those insights to realize additional revenue opportunities. So, what has changed to make the Internet of Things one of the hottest topics in tech? In his session at @ThingsExpo, Chris Gray, Director, Embedded and Internet of Things, discussed the underlying factors that are driving the economics of intelligent systems. Discover ...
Nov. 20, 2014 12:30 PM EST Reads: 1,673
Cochlear Limited, the global leader in implantable hearing solutions, has selected AppZero for easy migration of its Microsoft Windows Server 2003 applications, a major priority for IT organizations before Microsoft ends support on July 14, 2015. AppZero software enables server application migration from old operating systems to new platforms or clouds and has been proven to be ten times faster, more reliable and efficient than alternative approaches.
Nov. 20, 2014 10:24 AM EST Reads: 665
Fundamentally, SDN is still mostly about network plumbing. While plumbing may be useful to tinker with, what you can do with your plumbing is far more intriguing. A rigid interpretation of SDN confines it to Layers 2 and 3, and that's reasonable. But SDN opens opportunities for novel constructions in Layers 4 to 7 that solve real operational problems in data centers. "Data center," in fact, might become anachronistic - data is everywhere, constantly on the move, seemingly always overflowing. Net...
Nov. 20, 2014 07:30 AM EST Reads: 1,249
SYS-CON Media announced today the IBM, which offers the world’s deepest portfolio of technologies and expertise that are transforming the future of work, has launched ad campaigns on SYS-CON’s numerous online magazines such as Cloud Computing Journal, DevOps Journal, Virtualization Journal, and IoT Journal. IBM's campaigns focus on application testing, improving application development processes, common challenges in testing composite applications, continuous testing as part of the DevOps lifec...
Nov. 19, 2014 08:15 PM EST Reads: 1,455