Java IoT Authors: Liz McMillan, Pat Romanski, Carmen Gonzalez, Elizabeth White, TJ Randall

Related Topics: @CloudExpo, Microservices Expo, Containers Expo Blog

@CloudExpo: Article

Challenges and Best Practices for Load Testing with the Cloud

Part 2: The key is to think of cloud testing as the delivery mechanism

In Part 1 I described how the cloud is revolutionizing load testing and the advantages it provides to ensure that your web applications perform well in production. We also looked at what capabilities you should seek out when selecting a load testing solution.

In Part 2, I will offer the limitations of a test strategy that relies solely on cloud-based testing, highlighting the need for a complementary internal load testing solution. I will also discuss several best practices for load testing in the cloud. Understanding how to apply the right tools and practices to make the most of the cloud is fundamental to cloud-based testing and vital to ultimately going live with total peace of mind.

The advantages to load testing with the cloud are clear, but internal testing still has its place in the overall test plan, particularly when testing from outside the firewall is not feasible. Internal testing also helps you to isolate effects that are due to your own application or infrastructure from those that are outside your firewall and potentially beyond your control.

The advantages to load testing with the cloud are clear, but internal testing still has its place in the overall test plan, particularly when testing from outside the firewall is not feasible. Internal testing also helps you to isolate effects that are due to your own application or infrastructure from those that are outside your firewall and potentially beyond your control.

Isolating Root Cause
When load testing uncovers a problem, the next step is identifying which layer in the delivery chain is causing the problem. You can use monitors to check performance metrics such has hits, average response time per request, and average bandwidth for each layer or piece of equipment in the chain. You can also employ application performance management (APM) solutions to identify bottlenecks in the code. These techniques work reasonably well when there is a single source for the performance slow-down.

When there are multiple problems, both inside and outside the firewall, it can be difficult to sort out the root causes because the symptoms are often commingled, making them difficult to isolate and resolve individually. For this reason it's important to have a cloud load testing solution that you can also apply within the firewall. You can then separate the problems that exist within the firewall from those caused by layers outside it. The ability to test a subset of the delivery chain in this way makes it much easier to find the root causes of performance problems.

Reproducing Tests
Often, you need to precisely measure the effect of changes made to the application code or settings. For example, you may need to determine the performance improvement that results from resolving a specific defect or evaluate performance for a range of cache sizes and other settings.

With cloud load testing, such precise measurements are difficult because of variations in Internet traffic and bandwidth availability at the data center level. Such variations can make it almost impossible to duplicate conditions from day to day or even within the same day.

As with isolating root causes, this situation also highlights the need for internal testing, in which you can better manage the conditions of the test, stabilize the testing environment, and take precise measurements to get more reliable performance metrics for comparison.

Conducting Small Scale Tests
Not all load testing requires hundreds of load generators. Even applications that anticipate many thousands of concurrent users are initially tested with a small population. These smaller scale tests require only a few machines may be easier and less expensive to conduct internally if the machines have already been purchased and are available for use. These tests can be carried out within the firewall to conduct tests that don't require a heavy load or the full delivery chain. To keep cloud expenses down, use available real machines when they can provide the information you need, and employ load testing with the cloud when necessary for larger scale, more realistic tests.

Testing Inside the Firewall
Of course, some testing use cases preclude the use of the cloud. If you're developing an enterprise web application that was not designed to be accessed from the Internet, then it's not a good idea to expose it outside the firewall solely for the purpose of load testing with the cloud. Likewise, if your pre-production environment is not set up to be accessed from the Internet, you'll want to have an internal testing solution that can be used within the firewall. Ideally, you want to use the same load testing solution for both internal testing and testing with the cloud, so that the scripts you developed for internal pre-production testing can be reused in production cloud-based testing. Using different tools for internal and cloud testing would not only require a rewrite of the scripts, it would also increase licensing and training costs.

Best Practices
The following best practices can help you maximize the advantages - and minimize the challenges - of load testing with the cloud.

Employ a Two-Stage Process
A two-stage process for load testing enables engineers to employ internal and cloud testing in the situations for which they are most effective and appropriate. In the first stage of the process you conduct internal tests with a medium load to quickly identify and resolve preliminary performance issues. Then increase the load incrementally with one or more load generators in the test lab. After the performance has been validated internally, proceed to the second stage, cloud-based load testing, for large scale tests that validate the entire delivery chain of the application.

This hybrid approach addresses the key challenges facing organizations that attempt to rely on testing from the cloud only:

  • It enables teams to isolate problems. The source of any performance issue identified in the first stage is clearly within the firewall (because no other systems are involved in the test). It's easier to pinpoint and fix internal problems when they are not being compounded by other issues that originate outside the firewall.
  • It enables earlier testing. With the two-stage process, you don't have to wait for the application to be deployed and accessible from the Internet to test it. You can test internally earlier in the application lifecycle when defects are easier and less expensive to fix.
  • It enables reproducible tests. With internal testing you have much more control over the environment, so you can precisely measure the effect of code or configuration changes on application performance.
  • It provides a better understanding of each major area of the delivery chain. You can compare the results of the same test scenario run internally and from the cloud to get a clearer picture of how the application server and network infrastructure contribute to overall response times.
  • It lowers costs. Cloud testing is based on a pay-per-use model. When you can test internally on hardware you already have, you can reduce the amount of testing that you need to perform from the cloud and cut costs.

Use Different Cloud Providers
There are several advantages to using multiple cloud providers. First, it helps you test from more geographical regions, which provides more realistic results that capture the effects of various third-party servers and content delivery networks. Second, it's more scalable. For exceptionally large scale tests, you can engage multiple providers simultaneously to bypass limitations that a single provider may place on bandwidth or the number of machines in use. Third, it enables you to detect potential network issues at the cloud provider level. If test results from virtually all providers show acceptable performance, but you're seeing significantly worse performance from machines on a particular provider, then you can safely conclude that there is a temporary problem with only that provider, not your application. Load testing solutions that are locked into a single provider limit the test engineer's ability to conduct realistic, reliable, large-scale tests.

Secure Your Data
In internal pre-production testing, the data used is often fake - not actual customer or user information. Further, you can be reasonably assured that any real data used is safe because testing is being conducted within the firewall. This is not the case when testing from the cloud on production data. You'll need to take steps to ensure that any accounts, scenarios, detailed error messages, and other sensitive data involved in your tests are secured.

Encrypt the communication between your controller and load generators. This helps secure data sent to the load generators during the test (including account information) as well as the data that is retrieved (including error messages). If possible, use SSL to secure the communication between the browser and the tested server. Last, ensure your load generators are secured with their own firewalls to protect them from outside threats.

Tune Load Generators
To ensure that your load generator machines in the cloud are capable of generating large loads, you must properly tune the system to support the creation of a high number of sockets and threads per process. In addition, allocate an appropriate heap size for Java-based load generators. The default settings for a typical machine allow all programs to share its resources fairly. In the case of load generators, the machine is dedicated to a single task, so you can improve performance by allocating a significantly larger share of the available resources to the load generation tasks.

Monitor Your Servers
Once you've identified a performance bottleneck, you need information to track down its root cause. This information should be gathered during the test by monitoring each component of the infrastructure including application servers and database servers. Specifically, you want to monitor both the system - including the operating system, disks, and network - and the server software - including connection pools, threads, cache hits, and indexes.

Linking all the information gathered during the tests with the tests themselves is much easier when the monitoring is integrated with your load testing tool. This enables you to correlate the response times and errors generated by load testing with the monitored data to track down the cause of problems quickly. A cloud testing solution that has no ability to monitor activity inside the firewall cannot integrate and correlate the tests it initiates from the outside with what is happening on the inside. With such a setup, test engineers will not have all the information they need to quickly identify the sources of performance problems.

Summing It Up
Even with all its potential benefits, cloud testing cannot meet all the challenges facing performance test engineers. In practice, cloud testing is most effective when combined with internal load testing in a two-stage process that makes use of multiple cloud providers and both internal and external infrastructure. You can be optimistic about using the cloud, but don't get caught up in all the hype. The key is to think of cloud testing as the delivery mechanism that is just one (albeit an important one) part of an overall load and performance test strategy.

More Stories By Steve Weisfeldt

Steve Weisfeldt is a Senior Performance Engineer at Neotys, a provider of load testing software for Web applications. Previously, he has worked as the President of Engine 1 Consulting, a services firm specializing in all facets of test automation. Prior to his involvement at Engine 1 Consulting, he was a Senior Systems Engineer at Aternity. Prior to that, Steve spent seven years at automated testing vendor Segue Software (acquired by Borland). While spending most of his time at Segue delivering professional services and training, he was also involved in pre-sales and product marketing efforts.

Being in the load and performance testing space since 1999, Steve has been involved in load and performance testing projects of all sizes, in industries that span the retail, financial services, insurance and manufacturing sectors. His expertise lies in enabling organizations to optimize their ability to develop, test and launch high-quality applications efficiently, on-time and on-budget. Steve graduated from the University of Massachusetts-Lowell with a BS in Electrical Engineering and an MS in Computer Engineering.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.

@ThingsExpo Stories
November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Penta Security is a leading vendor for data security solutions, including its encryption solution, D’Amo. By using FPE technology, D’Amo allows for the implementation of encryption technology to sensitive data fields without modification to schema in the database environment. With businesses having their data become increasingly more complicated in their mission-critical applications (such as ERP, CRM, HRM), continued ...
SYS-CON Events announced today that Enzu will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Enzu’s mission is to be the leading provider of enterprise cloud solutions worldwide. Enzu enables online businesses to use its IT infrastructure to their competitive advantage. By offering a suite of proven hosting and management services, Enzu wants companies to focus on the core of their online busine...
For basic one-to-one voice or video calling solutions, WebRTC has proven to be a very powerful technology. Although WebRTC’s core functionality is to provide secure, real-time p2p media streaming, leveraging native platform features and server-side components brings up new communication capabilities for web and native mobile applications, allowing for advanced multi-user use cases such as video broadcasting, conferencing, and media recording.
SYS-CON Events announced today that Cloudbric, a leading website security provider, will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Cloudbric is an elite full service website protection solution specifically designed for IT novices, entrepreneurs, and small and medium businesses. First launched in 2015, Cloudbric is based on the enterprise level Web Application Firewall by Penta Security Sys...
Established in 1998, Calsoft is a leading software product engineering Services Company specializing in Storage, Networking, Virtualization and Cloud business verticals. Calsoft provides End-to-End Product Development, Quality Assurance Sustenance, Solution Engineering and Professional Services expertise to assist customers in achieving their product development and business goals. The company's deep domain knowledge of Storage, Virtualization, Networking and Cloud verticals helps in delivering ...
The best way to leverage your Cloud Expo presence as a sponsor and exhibitor is to plan your news announcements around our events. The press covering Cloud Expo and @ThingsExpo will have access to these releases and will amplify your news announcements. More than two dozen Cloud companies either set deals at our shows or have announced their mergers and acquisitions at Cloud Expo. Product announcements during our show provide your company with the most reach through our targeted audiences.
In the next five to ten years, millions, if not billions of things will become smarter. This smartness goes beyond connected things in our homes like the fridge, thermostat and fancy lighting, and into heavily regulated industries including aerospace, pharmaceutical/medical devices and energy. “Smartness” will embed itself within individual products that are part of our daily lives. We will engage with smart products - learning from them, informing them, and communicating with them. Smart produc...
SYS-CON Events announced today that 910Telecom will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Housed in the classic Denver Gas & Electric Building, 910 15th St., 910Telecom is a carrier-neutral telecom hotel located in the heart of Denver. Adjacent to CenturyLink, AT&T, and Denver Main, 910Telecom offers connectivity to all major carriers, Internet service providers, Internet backbones and ...
SYS-CON Events announced today that Coalfire will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. Coalfire is the trusted leader in cybersecurity risk management and compliance services. Coalfire integrates advisory and technical assessments and recommendations to the corporate directors, executives, boards, and IT organizations for global brands and organizations in the technology, cloud, health...
SYS-CON Events announced today that Transparent Cloud Computing (T-Cloud) Consortium will exhibit at the 19th International Cloud Expo®, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. The Transparent Cloud Computing Consortium (T-Cloud Consortium) will conduct research activities into changes in the computing model as a result of collaboration between "device" and "cloud" and the creation of new value and markets through organic data proces...
The Internet of Things (IoT), in all its myriad manifestations, has great potential. Much of that potential comes from the evolving data management and analytic (DMA) technologies and processes that allow us to gain insight from all of the IoT data that can be generated and gathered. This potential may never be met as those data sets are tied to specific industry verticals and single markets, with no clear way to use IoT data and sensor analytics to fulfill the hype being given the IoT today.
WebRTC defines no default signaling protocol, causing fragmentation between WebRTC silos. SIP and XMPP provide possibilities, but come with considerable complexity and are not designed for use in a web environment. In his session at @ThingsExpo, Matthew Hodgson, technical co-founder of the Matrix.org, discussed how Matrix is a new non-profit Open Source Project that defines both a new HTTP-based standard for VoIP & IM signaling and provides reference implementations.
In his general session at 18th Cloud Expo, Lee Atchison, Principal Cloud Architect and Advocate at New Relic, discussed cloud as a ‘better data center’ and how it adds new capacity (faster) and improves application availability (redundancy). The cloud is a ‘Dynamic Tool for Dynamic Apps’ and resource allocation is an integral part of your application architecture, so use only the resources you need and allocate /de-allocate resources on the fly.
We're entering the post-smartphone era, where wearable gadgets from watches and fitness bands to glasses and health aids will power the next technological revolution. With mass adoption of wearable devices comes a new data ecosystem that must be protected. Wearables open new pathways that facilitate the tracking, sharing and storing of consumers’ personal health, location and daily activity data. Consumers have some idea of the data these devices capture, but most don’t realize how revealing and...
A completely new computing platform is on the horizon. They’re called Microservers by some, ARM Servers by others, and sometimes even ARM-based Servers. No matter what you call them, Microservers will have a huge impact on the data center and on server computing in general. Although few people are familiar with Microservers today, their impact will be felt very soon. This is a new category of computing platform that is available today and is predicted to have triple-digit growth rates for some ...
SYS-CON Events announced today that MathFreeOn will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. MathFreeOn is Software as a Service (SaaS) used in Engineering and Math education. Write scripts and solve math problems online. MathFreeOn provides online courses for beginners or amateurs who have difficulties in writing scripts. In accordance with various mathematical topics, there are more tha...
In past @ThingsExpo presentations, Joseph di Paolantonio has explored how various Internet of Things (IoT) and data management and analytics (DMA) solution spaces will come together as sensor analytics ecosystems. This year, in his session at @ThingsExpo, Joseph di Paolantonio from DataArchon, will be adding the numerous Transportation areas, from autonomous vehicles to “Uber for containers.” While IoT data in any one area of Transportation will have a huge impact in that area, combining sensor...
SYS-CON Events announced today that SoftNet Solutions will exhibit at the 19th International Cloud Expo, which will take place on November 1–3, 2016, at the Santa Clara Convention Center in Santa Clara, CA. SoftNet Solutions specializes in Enterprise Solutions for Hadoop and Big Data. It offers customers the most open, robust, and value-conscious portfolio of solutions, services, and tools for the shortest route to success with Big Data. The unique differentiator is the ability to architect and ...
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smar...
@ThingsExpo has been named the Top 5 Most Influential Internet of Things Brand by Onalytica in the ‘The Internet of Things Landscape 2015: Top 100 Individuals and Brands.' Onalytica analyzed Twitter conversations around the #IoT debate to uncover the most influential brands and individuals driving the conversation. Onalytica captured data from 56,224 users. The PageRank based methodology they use to extract influencers on a particular topic (tweets mentioning #InternetofThings or #IoT in this ...