|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".
I’ve been thinking a bit about microservices (μServices) recently. My immediate reaction is to think: “Isn’t this just yet another new term for the same stuff, Web Services->SOA->APIs->Microservices?” Followed shortly by the thought, “well yes it is, but there are some important differences/distinguishing factors.” Microservices is an evolutionary paradigm born out of the need for simplicity (i.e., get away from the ESB) and alignment with agile (think DevOps) and scalable (think Containerizati...
May. 27, 2015 03:00 PM EDT Reads: 1,687
In her General Session at 15th Cloud Expo, Anne Plese, Senior Consultant, Cloud Product Marketing, at Verizon Enterprise, focused on finding the right mix of renting vs. buying Oracle capacity to scale to meet business demands, and offer validated Oracle database TCO models for Oracle development and testing environments. Anne Plese is a marketing and technology enthusiast/realist with over 19+ years in high tech. At Verizon Enterprise, she focuses on driving growth for the Verizon Cloud platfo...
May. 27, 2015 03:00 PM EDT Reads: 5,628
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 at launch. DevOps may be disruptive, but it is essential. The DevOps Summit at Cloud Expo – to be held June 3-5, 2015, at the Javits Center in New York City – will expand the DevOps community, enable a wide...
May. 27, 2015 03:00 PM EDT Reads: 2,744
I read an insightful article this morning from Bernard Golden on DZone discussing the DevOps conundrum facing many enterprises today – is it better to build your own DevOps tools or go commercial? For Golden, the question arose from his observations at a number of DevOps Days events he has attended, where typically the audience is composed of startup professionals: “I have to say, though, that a typical feature of most presentations is a recitation of the various open source products and compo...
May. 27, 2015 02:45 PM EDT Reads: 919
Many people recognize DevOps as an enormous benefit – faster application deployment, automated toolchains, support of more granular updates, better cooperation across groups. However, less appreciated is the journey enterprise IT groups need to make to achieve this outcome. The plain fact is that established IT processes reflect a very different set of goals: stability, infrequent change, hands-on administration, and alignment with ITIL. So how does an enterprise IT organization implement change...
May. 27, 2015 02:30 PM EDT Reads: 907
Cloud Expo, Inc. has announced today that Andi Mann returns to DevOps Summit 2015 as Conference Chair. The 4th International DevOps Summit will take place on June 9-11, 2015, at the Javits Center in New York City. "DevOps is set to be one of the most profound disruptions to hit IT in decades," said Andi Mann. "It is a natural extension of cloud computing, and I have seen both firsthand and in independent research the fantastic results DevOps delivers. So I am excited to help the great team at ...
May. 27, 2015 02:00 PM EDT Reads: 2,279
Software is eating the world. Companies that were not previously in the technology space now find themselves competing with Google and Amazon on speed of innovation. As the innovation cycle accelerates, companies must embrace rapid and constant change to both applications and their infrastructure, and find a way to deliver speed and agility of development without sacrificing reliability or efficiency of operations. In her Day 2 Keynote DevOps Summit, Victoria Livschitz, CEO of Qubell, discussed...
May. 27, 2015 02:00 PM EDT Reads: 5,812
SYS-CON Events announced today that MetraTech, now part of Ericsson, has been named “Silver Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9–11, 2015, at the Javits Center in New York, NY. Ericsson is the driving force behind the Networked Society- a world leader in communications infrastructure, software and services. Some 40% of the world’s mobile traffic runs through networks Ericsson has supplied, serving more than 2.5 billion subscribers.
May. 27, 2015 02:00 PM EDT Reads: 2,110
The 5th International DevOps Summit, co-located with 17th International Cloud Expo – being held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA – announces that its Call for Papers is 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...
May. 27, 2015 02:00 PM EDT Reads: 4,675
How does one bridge the gap between traditional enterprise storage infrastructures and the private, hybrid, and public cloud? In his session at 15th Cloud Expo, Dan Pollack, Chief Architect of Storage Operations at AOL Inc., examed the workload differences and required changes to reuse existing knowledge and components when building and using a cloud infrastructure. He also looked into the operational considerations, tool requirements, and behavioral changes required for private cloud storage s...
May. 27, 2015 02:00 PM EDT Reads: 2,909
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 ...
May. 27, 2015 02:00 PM EDT Reads: 5,090
In the first four parts of this series I presented an introduction to microservices along with a handful of emerging microservices patterns, and a discussion of some of the downsides and challenges to using microservices. The most recent installment of this series looked at ten ways that PaaS facilitates microservices development and adoption. In this post I’ll cover some words of wisdom, advice intended for individuals, teams, and organizations considering a move to microservices. I've gleaned...
May. 27, 2015 01:30 PM EDT Reads: 2,923
Virtualization is everywhere. Enormous and highly profitable companies have been built on nothing but virtualization. And nowhere has virtualization made more of an impact than in Cloud Computing, the rampant and unprecedented adoption of which has been the direct result of the wide availability of virtualization software and techniques that enabled it. But does the cloud actually require virtualization?
May. 27, 2015 01:00 PM EDT Reads: 2,030
Working with Big Data is challenging, especially when decision makers depend on market insights and intelligence from your data but don't have quick access to it or find it unusable. In their session at 6th Big Data Expo, Ian Khan, Global Strategic Positioning & Brand Manager at Solgenia; Zel Bianco, President, CEO and Co-Founder of Interactive Edge of Solgenia; and Ermanno Bonifazi, CEO & Founder at Solgenia, discussed how a revolutionary cloud-based BI along with mobile analytics is already c...
May. 27, 2015 01:00 PM EDT Reads: 5,653
Hardware will never be more valuable than on the day it hits your loading dock. Each day new servers are not deployed to production the business is losing money. While Moore's Law is typically cited to explain the exponential density growth of chips, a critical consequence of this is rapid depreciation of servers. The hardware for clustered systems (e.g., Hadoop, OpenStack) tends to be significant capital expenses. In his session at Big Data Expo, Mason Katz, CTO and co-founder of StackIQ, disc...
May. 27, 2015 12:30 PM EDT Reads: 5,529
Enterprises are fast realizing the importance of integrating SaaS/Cloud applications, API and on-premises data and processes, to unleash hidden value. This webinar explores how managers can use a Microservice-centric approach to aggressively tackle the unexpected new integration challenges posed by proliferation of cloud, mobile, social and big data projects. Industry analyst and SOA expert Jason Bloomberg will strip away the hype from microservices, and clearly identify their advantages and d...
May. 27, 2015 12:00 PM EDT Reads: 2,513
The 4th International Internet of @ThingsExpo, co-located with the 17th International Cloud Expo - to be held November 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA - announces that its Call for Papers is open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
May. 27, 2015 12:00 PM EDT Reads: 2,402
Containers Expo Blog covers the world of containers, as this lightweight alternative to virtual machines enables developers to work with identical dev environments and stacks. Containers Expo Blog offers top articles, news stories, and blog posts from the world's well-known experts and guarantees better exposure for its authors than any other publication. Bookmark Containers Expo Blog ▸ Here Follow new article posts on Twitter at @ContainersExpo
May. 27, 2015 12:00 PM EDT Reads: 1,604
T-Mobile has been transforming the wireless industry with its “Uncarrier” initiatives. Today as T-Mobile’s IT organization works to transform itself in a like manner, technical foundations built over the last couple of years are now key to their drive for more Agile delivery practices. In his session at DevOps Summit, Martin Krienke, Sr Development Manager at T-Mobile, will discuss where they started their Continuous Delivery journey, where they are today, and where they are going in an effort ...
May. 27, 2015 11:00 AM EDT Reads: 2,179
SYS-CON Events announced today that EnterpriseDB (EDB), the leading worldwide provider of enterprise-class Postgres products and database compatibility solutions, 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. EDB is the largest provider of Postgres software and services that provides enterprise-class performance and scalability and the open source freedom to divert budget from more costly traditiona...
May. 27, 2015 11:00 AM EDT Reads: 2,109