Welcome!

AJAX & REA Authors: Pat Romanski, Kevin Benedict, Gary Kaiser, Michael Bushong, RealWire News Distribution

Related Topics: Java, XML, SOA & WOA, ColdFusion, .NET, AJAX & REA

Java: Article

Eleven Tips to Becoming a Better Performance Engineer

How to conduct performance testing

The ability to conduct effective performance testing has become a highly desired skillset within the IT industry. Unfortunately, these highly sought-after skills are consistently in short supply. "Front-end testers" can work with a tool to create a realistic load and although this is an important skillset, creating the load is just the beginning of any performance project. Understanding the load patterns and tuning the environment makes the unique talents of a "performance engineer" worth their weight in gold.

Performance engineers require skills in data analysis such as resource usage patterns, modeling, capacity planning, and tuning in order to detect, isolate, and alleviate saturation points within a deployment. Performance testing generates concurrency conditions and exposes resource competition at a server level. When the competition results in a resource (such as a thread pool) becoming over-utilized, this resource becomes a bottleneck or a saturation point. Performance engineers need to first understand the underlying architectures and develop a sense of where to look for potential scalability issues. Much of these "senses" or skills come from experience, working in many multi-tier environments and successfully tuning bottlenecks. Here are some tips to make the challenging but rewarding transition from a front-end tester to a performance engineer.

Wisdom, Determination, Patience, and Communication
Who said there isn't a whole lot of psychology in technology? ;) Whether you are determining the current capacity of a deployment or you are recreating a production problem, it's often a very complex task- so many moving parts within the infrastructure, so many numbers to analyze from so many sources, data sets of raw test results to turn into understandable formats, so many people to keep in the loop, so much technical coordination... I could go on and on. It's your professional soft skills which will keep you on the right course. It requires determination to unpeel the layers of an onion and investigate each tier of the deployment. It requires the wisdom to spot trends instead of pursuing the tangents of anomalies. It requires the dedication to keep an eye on many different metrics and isolate resource saturation. And it requires the patience to reproduce scenarios in order to make conclusions based on proof/evidence. And you need to accomplish all of this while being an excellent communicator!

Methodical Approach - The Constant
Spend your time wisely in the beginning and set up the most realistic test scenarios. Then "set" the performance scenario in stone. This means Do Not change even the most minute details in your test case: All transactions flows, all mixtures, all think times, all behaviors - no variations at this point. This is the "constant" in your experiment and it is the only way you can reproduce and compare results. Any deviation within the test case scenario will result in different throughputs which affect resource patterns. Not following this tip will surely lead you on a collision course with Analysis Paralysis!

Architectural Diagram - Identify Potential Bottlenecks by Visualization
Make sure you ask for and receive an architectural diagram of the entire deployment. Map out business transactions to resources utilized within the environment. Make sure you understand all the transaction flows, from front end load balancers down to the shared resource database. Study the deployment and hook up precise monitors, leaving no blind spots. Visualize where contentions or bottlenecks COULD occur. Each resource of the environment must be monitored for signs of saturation. In reality, it's in the identification of where to look for bottlenecks that is the more difficult task. Alleviating these bottlenecks is the easy (and most rewarding) part. But without an architectural map, your journey will easily end by the frustration of getting lost in the dark.

Tuning Hardware and Software Level Bottlenecks
"Tuning is an Art". "Tuning is a Science". Which is it? Hardware servers are restricted by the physical resources (disk io/memory, cpu). Software servers are much more configurable and this is where expertise in needed for tuning. Performance engineers must understand the workings of a "server" in thread pools, caching policies, memory allocations, connection pooling, etc. Tuning is a balancing act. It's the situation where you tune the software servers in order to take full advantage of hardware resources, without causing a flood. Simply opening up all the gates isn't going to help when the backend is saturated with requests. Tuning must be conservative, weighing all the benefits as well as the consequences.

Proof: Reproducible Results
Typically, a seasoned performance engineer will tune a layer of the environment only when the results are reproducible. Always use trends instead of points in time, mere spikes are not cause for architectural changes. As a rule of thumb, you should reproduce 3 times before you make a change. Sometimes this takes a while... So be prepared to be patient. For example, if you are emulating a production login rate of 3 users per second, but the performance deterioration doesn't occur until you have 2000 active users, it will take a while to see it. Making an unnecessary change simply muddies the waters, keep it clear and recreate those exact conditions.

Tune the First Occurring Bottleneck
Make sure you tune the layer which showed contention earliest in the performance test, not the first identified bottleneck. When monitoring a large complex system, there are many counters to keep in your sights. Don't jump the gun and tune a thread pool when you see it becomes saturated, this could actually be a symptom of the problem, not the root cause. Correlate (using graphing is easiest) the point of time of degradation of performance to the first saturation within the environment. Understandably, there is a ton of information to look at - keep it simpler by just looking at the free resources based on percentages (free threads, free cache, and free file descriptors) and this will allow you to spot a bottleneck quicker. When a free resource runs low, there's a possible bottleneck. Understand the resource utilization and free resources will allow you to understand a bottleneck before it affects the end-user response time. In other words, watch as the resource becomes utilized. When free gets low, keep it on your radar for a cause of performance degradation.

Iterative Tuning Process
Tuning is an iterative process. Know that once you have alleviated one bottleneck, you will surely encounter another one. But do not fret... All aspects of servers are limited and since nothing is infinite you will eventually reach the end. Tuning manipulates the gates, requests which don't have a resource are queued and must wait to be serviced. Tuning becomes a process you must repeat until the workload reaches target capacity with acceptable response times.

Validation
Validate, validate, validate. Just as important as recreating and tuning based upon proof is validating that the tuning change had the desired effect. Did it indeed impact scalability in a positive way? Often, performance engineers test out theories. And sometimes, the validation stage will cause a change to be reverted. It's ok that not every change will make it to production. The key is to use a very scientific approach in which you prove the result as well as the requirement.

I hope you gleaned some pearls of wisdom.

Creating the load and emulating production workload is a means to end - you obviously need to create the load before you can capacity plan or understand the scalability of the deployment. But it is the skills in performance analysis that are most valuable. The performance engineer who walks into a project, takes the lead, wastes no time in learning the environment, creates and/or executes the realistic tests, identifies current capacity, isolates and alleviates bottlenecks, documents results, mentors the juniors, and clearly and effectively communicates with everyone from developers on up to the CIO/CTO's, is truly a GOLD MINE.

Becoming a true performance engineer is no easy task, but it's well worth the effort!

More Stories By Rebecca Clinard

Rebecca Clinard is a Senior Performance Engineer at Neotys, a provider of load testing software for Web applications. Previously, she worked as a web application performance engineer for Bowstreet, Fidelity Investments, Bottomline Technologies and Timberland companies, industries spanning retail, financial services, insurance and manufacturing. Her expertise lies in creating realistic load tests and performance tuning multi-tier deployments. She has been orchestrating and conducting performance tests since 2001. Clinard graduated from University of New Hampshire with a BS and also holds a UNIX Certificate from Worcester Polytechnic Institute.

Cloud Expo Breaking News
After a couple of false starts, cloud-based desktop solutions are picking up steam, driven by trends such as BYOD and pervasive high-speed connectivity. In his session at 15th Cloud Expo, Seth Bostock, CEO of IndependenceIT, cuts through the hype and the acronyms, and discusses the emergence of full-featured cloud workspaces that do for the desktop what cloud infrastructure did for the server. He’ll discuss VDI vs DaaS, implementation strategies and evaluation criteria.
There will be 50 billion Internet connected devices by 2020. Today, every manufacturer has a propriety protocol and an app. How do we securely integrate these "things" into our lives and businesses in a way that we can easily control and manage? Even better, how do we integrate these "things" so that they control and manage each other so our lives become more convenient or our businesses become more profitable and/or safe? We have heard that the best interface is no interface. In his session at Internet of @ThingsExpo, Chris Matthieu, Co-Founder & CTO at Octoblu, Inc., will discuss how these devices generate enough data to learn our behaviors and simplify/improve our lives. What if we could connect everything to everything? I'm not only talking about connecting things to things but also systems, cloud services, and people. Add in a little machine learning and artificial intelligence and now we have something interesting...
Cloud computing started a technology revolution; now DevOps is driving that revolution forward. By enabling new approaches to service delivery, cloud and DevOps together are delivering even greater speed, agility, and efficiency. No wonder leading innovators are adopting DevOps and cloud together! In his session at DevOps Summit, Andi Mann, Vice President of Strategic Solutions at CA Technologies, will explore the synergies in these two approaches, with practical tips, techniques, research data, war stories, case studies, and recommendations.
SYS-CON Events announced today that Cloudian, Inc., the leading provider of hybrid cloud storage solutions, has been named “Bronze Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Cloudian is a Foster City, Calif.-based software company specializing in cloud storage. Cloudian HyperStore® is an S3-compatible cloud object storage platform that enables service providers and enterprises to build reliable, affordable and scalable hybrid cloud storage solutions. Cloudian actively partners with leading cloud computing environments including Amazon Web Services, Citrix Cloud Platform, Apache CloudStack, OpenStack and the vast ecosystem of S3 compatible tools and applications. Cloudian's customers include Vodafone, Nextel, NTT, Nifty, and LunaCloud. The company has additional offices in China and Japan.
SYS-CON Events announced today that Esri has been named “Bronze Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Esri inspires and enables people to positively impact the future through a deeper, geographic understanding of the changing world around them. For more information, visit http://www.esri.com.
Cloud Computing is evolving into a Big Three of Amazon Web Services, Google Cloud, and Microsoft Azure. Cloud 360: Multi-Cloud Bootcamp, being held Nov 4–5, 2014, in conjunction with 15th Cloud Expo in Santa Clara, CA, delivers a real-world demonstration of how to deploy and configure a scalable and available web application on all three platforms. The Cloud 360 Bootcamp, led by Janakiram MSV, an analyst with Gigaom Research, is the first bootcamp that introduces the core concepts of Infrastructure as a Service (IaaS) based on the workings of the Big Three platforms – Amazon EC2, Google Compute Engine, and Azure VMs. Bootcamp attendees will get to see the big picture and also receive the knowledge needed to make the best cloud decisions for their business applications and entire enterprise IT organization.
The Internet of Things promises to transform businesses (and lives), but navigating the business and technical path to success can be difficult to understand. In his session at 15th Internet of @ThingsExpo, Chad Jones, Vice President, Product Strategy of LogMeIn's Xively IoT Platform, will show you how to approach creating broadly successful connected customer solutions using real world business transformation studies including New England BioLabs and more.
“Distrix fits into the overall cloud and IoT model around software-defined networking. There’s a broad category around software-defined networking that’s focused on data center, and we focus on the WAN,” explained Jay Friedman, President of Distrix, in this SYS-CON.tv interview at the Internet of @ThingsExpo, held June 10-12, 2014, at the Javits Center in New York City. Internet of @ThingsExpo 2014 Silicon Valley, November 4–6, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading IoT industry players in the world.
Scott Jenson leads a project called The Physical Web within the Chrome team at Google. Project members are working to take the scalability and openness of the web and use it to talk to the exponentially exploding range of smart devices. Nearly every company today working on the IoT comes up with the same basic solution: use my server and you'll be fine. But if we really believe there will be trillions of these devices, that just can't scale. We need a system that is open a scalable and by using the URL as a basic building block, we open this up and get the same resilience that the web enjoys.
“The Internet of Things is a wave that has arrived and it’s growing really fast. The concern at Aria Systems is making sure that people understand the ramifications of their attempts to monetize whatever it is they build on the Internet of Things," explained C Brendan O’Brien, Co-founder and Chief Architect at Aria Systems, in this SYS-CON.tv interview at the Internet of @ThingsExpo, held June 10-12, 2014, at the Javits Center in New York City. Internet of @ThingsExpo 2014 Silicon Valley, November 4–6, at the Santa Clara Convention Center in Santa Clara, CA, will feature technical sessions from a rock star conference faculty and the leading IoT industry players in the world.
The Internet of Things is a natural complement to the cloud and related technologies such as Big Data, analytics, and mobility. In his session at Internet of @ThingsExpo, Joe Weinman will lay out four generic strategies – digital disciplines – to exploit emerging digital technologies for strategic advantage. Joe Weinman has held executive leadership positions at Bell Labs, AT&T, Hewlett-Packard, and Telx, in areas such as corporate strategy, business development, product management, operations, and R&D.
SYS-CON Events announced today that DevOps.com has been named “Media Sponsor” of SYS-CON's “DevOps Summit at Cloud Expo,” which will take place on June 10–12, 2014, at the Javits Center in New York City, New York. DevOps.com is where the world meets DevOps. It is the largest collection of original content relating to DevOps on the web today Featuring up-to-the-minute news, feature stories, blogs, bylined articles and more, DevOps.com is where the thought leaders of the DevOps movement make their ideas known.
There are 182 billion emails sent every day, generating a lot of data about how recipients and ISPs respond. Many marketers take a more-is-better approach to stats, preferring to have the ability to slice and dice their email lists based numerous arbitrary stats. However, fundamentally what really matters is whether or not sending an email to a particular recipient will generate value. Data Scientists can design high-level insights such as engagement prediction models and content clusters that allow marketers to cut through the noise and design their campaigns around strong, predictive signals, rather than arbitrary statistics. SendGrid sends up to half a billion emails a day for customers such as Pinterest and GitHub. All this email adds up to more text than produced in the entire twitterverse. We track events like clicks, opens and deliveries to help improve deliverability for our customers – adding up to over 50 billion useful events every month. While SendGrid data covers only abo...
SYS-CON Events announced today that the Web Host Industry Review has been named “Media Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. Since 2000, The Web Host Industry Review has made a name for itself as the foremost authority of the Web hosting industry providing reliable, insightful and comprehensive news, reviews and resources to the hosting community. TheWHIR Blogs provides a community of expert industry perspectives. The Web Host Industry Review Magazine also offers a business-minded, issue-driven perspective of interest to executives and decision-makers. WHIR TV offers on demand web hosting video interviews and web hosting video features of the key persons and events of the web hosting industry. WHIR Events brings together like-minded hosting industry professionals and decision-makers in local communities. TheWHIR is an iNET Interactive property.
SYS-CON Events announced today that O'Reilly Media has been named “Media Sponsor” of SYS-CON's 15th International Cloud Expo®, which will take place on November 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA. O'Reilly Media spreads the knowledge of innovators through its books, online services, magazines, and conferences. Since 1978, O'Reilly Media has been a chronicler and catalyst of cutting-edge development, homing in on the technology trends that really matter and spurring their adoption by amplifying "faint signals" from the alpha geeks who are creating the future. An active participant in the technology community, the company has a long history of advocacy, meme-making, and evangelism.