Welcome!

AJAX & REA Authors: Elizabeth White, Trevor Parsons, Liz McMillan, Yeshim Deniz, Plutora Blog

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.

@CloudExpo Stories
The 3rd International Internet of @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 its Call for Papers is now open. The Internet of Things (IoT) is the biggest idea since the creation of the Worldwide Web more than 20 years ago.
Want to enable self-service provisioning of application environments in minutes that mirror production? Can you automatically provide rich data with code-level detail back to the developers when issues occur in production? In his session at DevOps Summit, David Tesar, Microsoft Technical Evangelist on Microsoft Azure and DevOps, will discuss how to accomplish this and more utilizing technologies such as Microsoft Azure, Visual Studio online, and Application Insights in this demo-heavy session.
Entuity®, a provider of enterprise-class network management solutions, today announced that it solidifies its position as a market leader through global enterprise customer acquisitions and a refined channel strategy. In 2014, Entuity increased new license revenues in EMEA by over 75 percent, and LATAM by over 125 percent as customers embraced Entuity for its highly automated solution and unified architecture. Entuity’s refined channel strategy focuses on even deeper strategic alignment with ke...
We are all here because we are sold on the transformative promise of The Cloud. But what good is all of this ephemeral, on-demand infrastructure if your usage doesn't actually improve the agility and speed of your business? How must Operations adapt in order to avoid stifling your Cloud initiative? In his session at DevOps Summit, Damon Edwards, co-founder and managing partner of the DTO Solutions, will highlight the successful organizational, process, and tooling patterns of high-performing c...
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...
Cloud Expo 2014 TV commercials will feature @ThingsExpo, which was launched in June, 2014 at New York City's Javits Center as the largest 'Internet of Things' event in the world.
“We help people build clusters, in the classical sense of the cluster. We help people put a full stack on top of every single one of those machines. We do the full bare metal install," explained Greg Bruno, Vice President of Engineering and co-founder of StackIQ, in this SYS-CON.tv interview at 15th Cloud Expo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
"People are a lot more knowledgeable about APIs now. There are two types of people who work with APIs - IT people who want to use APIs for something internal and the product managers who want to do something outside APIs for people to connect to them," explained Roberto Medrano, Executive Vice President at SOA Software, in this SYS-CON.tv interview at Cloud Expo, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
In this demo at 15th Cloud Expo, John Meza, Product Engineer at Esri, showed how Esri products hook into Hadoop cluster to allow you to do spatial analysis on the spatial data within your cluster, and he demonstrated rendering from a data center with ArcGIS Pro, a new product that has a brand new rendering engine.
"Blue Box has been around for 10-11 years, and last year we launched Blue Box Cloud. We like the term 'Private Cloud as a Service' because we think that embodies what we are launching as a product - it's a managed hosted private cloud," explained Giles Frith, Vice President of Customer Operations at Blue Box, in this SYS-CON.tv interview at DevOps Summit, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
The Software Defined Data Center (SDDC), which enables organizations to seamlessly run in a hybrid cloud model (public + private cloud), is here to stay. IDC estimates that the software-defined networking market will be valued at $3.7 billion by 2016. Security is a key component and benefit of the SDDC, and offers an opportunity to build security 'from the ground up' and weave it into the environment from day one. In his session at 16th Cloud Expo, Reuven Harrison, CTO and Co-Founder of Tufin,...
CloudBees, Inc., has announced a $23.5 million financing round, led by longtime CloudBees investor Lightspeed Venture Partners. Existing investors Matrix Partners, Verizon Ventures and Blue Cloud Ventures also participated in the round. The latest funding announcement follows earlier rounds of $4 million, $10.5 million and $10.8 million, bringing the total investment in CloudBees to just under $50 million since the company’s inception in 2010. Previous venture investment rounds were led by Ma...
“We are strong believers in the DevOps movement and our staff has been doing DevOps for large enterprise environments for a number of years. The solution that we build is intended to allow DevOps teams to do security at the speed of DevOps," explained Justin Lundy, Founder & CTO of Evident.io, in this SYS-CON.tv interview at DevOps Summit, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Media announced that Splunk, a provider of the leading software platform for real-time Operational Intelligence, has launched an ad campaign on Big Data Journal. Splunk software and cloud services enable organizations to search, monitor, analyze and visualize machine-generated big data coming from websites, applications, servers, networks, sensors and mobile devices. The ads focus on delivering ROI - how improved uptime delivered $6M in annual ROI, improving customer operations by minin...
The move in recent years to cloud computing services and architectures has added significant pace to the application development and deployment environment. When enterprise IT can spin up large computing instances in just minutes, developers can also design and deploy in small time frames that were unimaginable a few years ago. The consequent move toward lean, agile, and fast development leads to the need for the development and operations sides to work very closely together. Thus, DevOps become...
Puppet Labs on Wednesday released the DevOps Salary Report, based on salary data gathered from Puppet Labs' industry-recognized State of DevOps Report. The data confirms that market demand for DevOps skills is growing, and that DevOps engineers are among the highest paid IT practitioners today. That's because IT organizations today are grappling with how to be more agile and responsive to the business, while maintaining the stability of their infrastructure. DevOps practices, such as continuous ...
The cloud is becoming the de-facto way for enterprises to leverage common infrastructure while innovating and one of the biggest obstacles facing public cloud computing is security. In his session at 15th Cloud Expo, Jeff Aliber, a global marketing executive at Verizon, discussed how the best place for web security is in the cloud. Benefits include: Functions as the first layer of defense Easy operation –CNAME change Implement an integrated solution Best architecture for addressing network-l...
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...
Appcore deploys cloud for service providers based on the Apache Cloud set. In this demo at 15th Cloud Expo, Nate Gordon, Director of Technology at Appcore, shows their new product that's coming out in January - Appcore Atlas, which is focused on deploying private clouds based on CloudStack in 15 minutes or less. Our upcoming June 9-11, 2015, event in New York City will present a total of 10 simultaneous tracks (the largest conference content in the world) by an all-star faculty, over three days...
In this scenarios approach Joe Thykattil, Technology Architect & Sales at TimeWarner / Navisite, presented examples that will allow business-savvy professionals to make informed decisions based on a sound business model. This model covered the technology options in detail as well as a financial analysis. The TCO (Total Cost of Ownership) and ROI (Return on Investment) demonstrated how to start, develop and formulate a business case that will allow both small and large scale projects to achieve...