Click here to close now.

Welcome!

AJAX & REA Authors: Liz McMillan, Elizabeth White, Carmen Gonzalez, Pat Romanski, Kevin Benedict

Blog Feed Post

Load testing like a developer

Creating highly targeted load tests for your web server doesn’t have to be complicated. And it won’t be, at least not if you know what to look for.

The secret is to approach a load test with the mind of a developer. You’re not going to run a test just to punish your web server. You’re trying to gather valuable data that will aid you in keeping your web applications fast and responsive. To do this, let’s look at two simple steps to create a scientifically sound load test.

1. To plan your test, think like a user.
The first step is to outline exactly what type of web experience you’re testing for. Are you expecting users to log onto your site and remain for hours at a time? Or are a large number of users entering and leaving the site in short spurts? Or, are you expecting your about-to-be-released video to go viral, and you want to be sure your server can handle the load? No two websites are identical, and the same goes for the user experience on your site.

Let’s take a look at an example. An online shop might find it best to define the number of visits and purchases per hour that its servers must be able to handle. With this information, the shop can calculate it down to a value of each new visit and/or purchase per second. An example of this could be an hour-long test configured to send five new visitors to the site per second, simulate them surfing the product catalog, and have them start a new purchase every second.

2. Find the data that really matters.
Now that your load test is up and running, your next step is to comb through the mountain of incoming data to understand what’s happening on the server. During the load test for our hypothetical online shop, new simulated users are coming to the site and old simulated users are leaving the site. To judge the response time of the web server, we need to look at the number of parallel users. If the web server is slow, you’ll have a large number of virtual users, and if it’s fast, that number will be smaller.

When the results of a load test show unacceptable response times, it is often assumed that the network is the cause of the problem. In reality, this is seldom the case. Fortunately, it is quite easy to check this using test measurement data. Simply compare the response time for a static image (such as JPEG, GIF, or PNG) with the response time for a dynamically created HTML page of approximately the same size.

Consider this example:
A) The response time for a static GIF image of 200 kB is measured at 60 milliseconds.
B) The response time for a dynamically created HTML page with a size of 400 kB is measured at three seconds.

Assuming the response time of the static image depends solely on the network bandwidth (which is not always the case, but is useful for our purposes in this example), the dynamically created HTML page should have a response time of 120 milliseconds since it is only twice the size of the image. Since the actual response time of the HTML page is three seconds, the web application uses at least 2880 milliseconds (3000 minus 120) to produce and send the page.

However, one successful test does not guarantee a perfect application. You should be running load tests after any modification is made to the web server or application (i.e. new software release, upgrading database, etc.). These tests should run for at least 30 minutes, because often a web server does not crash instantly when it’s overloaded. Many can handle a large load for a few minutes, but might crash later after 15 or 20.

With these tips in mind, you’ll be on track to pinpointing your application’s performance issues. Perfection takes time, but as you tweak your tests to emulate your real-world traffic, your response times should gradually improve.

Read the original blog entry...

More Stories By Sven Hammar

Sven Hammar is Co-Founder and CEO of Apica. In 2005, he had the vision of starting a new SaaS company focused on application testing and performance. Today, that concept is Apica, the third IT company I’ve helped found in my career.

Before Apica, he co-founded and launched Celo Commuication, a security company built around PKI (e-ID) solutions. He served as CEO for three years and helped grow the company from five people to 85 people in two years. Right before co-founding Apica, he served as the Vice President of Marketing Bank and Finance at the security company Gemplus (GEMP).

Sven received his masters of science in industrial economics from the Institute of Technology (LitH) at Linköping University. When not working, you can find Sven golfing, working out, or with family and friends.

@CloudExpo Stories
SYS-CON Events announced today that ActiveState, the leading independent Cloud Foundry and Docker-based PaaS provider, has been named “Silver Sponsor” of SYS-CON's DevOps Summit New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. ActiveState believes that enterprises gain a competitive advantage when they are able to quickly create, deploy and efficiently manage software solutions that immediately create business value, but they face many challenges that ...
SYS-CON Events announced today that Vitria Technology, Inc. will exhibit at SYS-CON’s @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Vitria will showcase the company’s new IoT Analytics Platform through live demonstrations at booth #330. Vitria’s IoT Analytics Platform, fully integrated and powered by an operational intelligence engine, enables customers to rapidly build and operationalize advanced analytics to deliver timely business outcomes ...
SYS-CON Events announced today that Alert Logic, the leading provider of Security-as-a-Service solutions for the cloud, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® and DevOps Summit 2015 New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY, and the 17th International Cloud Expo® and DevOps Summit 2015 Silicon Valley, which will take place November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Plutora, Inc., the leading global provider of enterprise release management and test environment management SaaS solutions, will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Headquartered in Mountain View, California, Plutora provides enterprise release management and test environment SaaS solutions to clients in North America, Europe and Asia Pacific. Leading companies ...
SYS-CON Events announced today that kintone has been named “Bronze 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 City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. kintone promotes cloud-based workgroup productivity, transparency and profitability with a seamless collaboration space, build your own business applic...
SYS-CON Events announced today that Akana, formerly SOA Software, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Akana’s comprehensive suite of API Management, API Security, Integrated SOA Governance, and Cloud Integration solutions helps businesses accelerate digital transformation by securely extending their reach across multiple channels – mobile, cloud and Internet of Thi...
SYS-CON Events announced today that CommVault has been named “Bronze 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 City, NY, and the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. A singular vision – a belief in a better way to address current and future data management needs – guides CommVault in the development of Singular In...
SYS-CON Events announced today that SafeLogic has been named “Bag Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. SafeLogic provides security products for applications in mobile and server/appliance environments. SafeLogic’s flagship product CryptoComply is a FIPS 140-2 validated cryptographic engine designed to secure data on servers, workstations, appliances, mobile devices, and in the Cloud....
SYS-CON Events announced today that FierceDevOps 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. FierceDevOps keeps software developers and IT operations personnel updated on the latest news and trends around the rapidly evolving role of the traditional IT worker.
SYS-CON Events announced today that QTS Realty Trust, one of the nation’s largest and fastest-growing providers of data center facilities and cloud services and a leader in security and compliance, 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. QTS Realty Trust, Inc. (NYSE: QTS) is a leading national provider of data center solutions and fully managed services, and a leader in security and compliance...
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...
SYS-CON Events announced today that IndependenceIT, a leading software provider of simplified IT management solutions for workspaces, applications and desktops-as-a-service, 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. IndependenceIT's Cloud Workspace® Suite combines application, end-user and infrastructure management into a seamless, easy-to-manage platform, with a unified management interface an...
SYS-CON Events announced today that WSM International (WSM), the world’s leading cloud and server migration services provider, 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. WSM is a solutions integrator with a core focus on cloud and server migration, transformation and DevOps services.
SYS-CON Events announced today that that Innodisk, the service-driven provider of industrial embedded flash and DRAM storage products and technologies, 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. Innodisk is a service-driven provider of industrial embedded flash and DRAM storage products and technologies. With satisfied customers across the embedded, aerospace and defense, cloud storage markets an...
SYS-CON Events announced today that StorPool Storage 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. StorPool is distributed storage software that allows service providers, enterprises and other cloud builders to run data storage on standard x86 servers, instead of using expensive and inefficient storage arrays (SAN).
SYS-CON Events announced today that Site24x7, the cloud infrastructure monitoring service, 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. Site24x7 is a cloud infrastructure monitoring service that helps monitor the uptime and performance of websites, online applications, servers, mobile websites and custom APIs. The monitoring is done from 50+ locations across the world and from various wireless carr...
SYS-CON Events announced today that B2Cloud, a provider of enterprise resource planning software, 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. B2cloud develops the software you need. They have the ideal tools to help you work with your clients. B2Cloud’s main solutions include AGIS – ERP, CLOHC, AGIS – Invoice, and IZUM
SYS-CON Events announced today that Intelligent Systems Services 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. Established in 1994, Intelligent Systems Services Inc. is located near Washington, DC, with representatives and partners nationwide. ISS’s well-established track record is based on the continuous pursuit of excellence in designing, implementing and supporting nationwide clients’ mission-cri...
While DevOps most critically and famously fosters collaboration, communication, and integration through cultural change, culture is more of an output than an input. In order to actively drive cultural evolution, organizations must make substantial organizational and process changes, and adopt new technologies, to encourage a DevOps culture. Moderated by Andi Mann, panelists will discuss how to balance these three pillars of DevOps, where to focus attention (and resources), where organizations m...
How do you securely enable access to your applications in AWS without exposing any attack surfaces? The answer is usually very complicated because application environments morph over time in response to growing requirements from your employee base, your partners and your customers. In his session at 16th Cloud Expo, Haseeb Budhani, CEO and Co-founder of Soha, will share five common approaches that DevOps teams follow to secure access to applications deployed in AWS, Azure, etc., and the frict...