- Advices

Advice

Why load test when you can quickly intervene in the event of a problem?

When a production problem occurs, response time is critical. The time required to identify and resolve the problem should not be underestimated. In fact, with the widespread use of n-tier architecture and multiple layers, the source of a performance glitch is often hard to pinpoint without the necessary tools.

Furthermore, how can you be sure the corrective measures work without a load testing tool that can reproduce the failure conditions?

Doesn't just adding more machines fix everything?

Most performance problems are due to a faulty software or network configuration, or a design fault in the application itself. Therefore, adding more machines isn't going to fix anything.

Let's say a database connection pool has been limited to a maximum size of 10 by mistake. In this case, no more than 10 users will be able to simultaneously access a page using that database, however many machines used and whatever their power.

Remember also that, as today's information systems are more dispersed and interconnected, their technological complexity increases the chances of performance problems occurring.

The real cost of testing

The main item to consider when costing a load testing campaign is manpower. With many load testing tools creating scenarios is a long and complicated affair, due to their outdated or too "techie" design. The manpower cost involved in creating scenarios in these cases quickly can become prohibitive.

Moreover, application development nowadays involves constant updating and fine-tuning, which means tests have to be re calibrated quickly to comply with the latest version. It's therefore important to take into account both the time required for initial development and that required for the -often numerous- updates.

The easier scenarios are to create, the more likely you are to create them; this means you can cover more test situations, thus improving your application's overall performance and reliability. So use your valuable time actually testing your application with NeoLoad, instead of wasting it writing pages and pages of test code with a badly-designed testing tool.

Creating scenarios easily with NeoLoad means you can carry out more tests, faster.

Why should I choose a tool that supports all these technologies (AJAX, Flex, Http/s...)?

An intranet or internet application undergoes several functional or technical upgrades in its lifetime. Thus, an initial version may feature only a selection of basic technologies,with subsequent versions gradually incorporating newer, more advanced technologies to support up-to-date business functions (such as a more ergonomic Flex or AJAX interface, or SSL support for access to secure areas).

So instead of choosing a tool that limits your technology options, choose NeoLoad, the load testing tool that grows with both your company and its applications.

Why use several generators?

Being able to choose the number of generators you use for a test is essential. You really need to use several machines to generate the load, according to the number of users you want to simulate. It's generally recommended to use a machine and network configuration with a generating capacity equal to the load you wish to test for.

Depending on your set-up, you may also need to generate load from a subnet or remote location. In this case, you need to have a generator placed at a strategic point that can be remotely controlled.

NeoLoad ships with unlimited load generators included in the price.

Can I generate more load using faster virtual users?

Contrary to popular belief, a server's load cannot be measured merely in terms of hits per second. This would imply that a small number of fast users uses up the same amount of resources as a large number of slow users. This is untrue, since each user session opened on the server uses up a certain amount of resources (memory, resource pools, network connections).

Artificially limiting the number of virtual users compared to the number of real users in production produces inaccurate results.

Doesn’t monitoring the servers mean installing intrusive elements?

Not with NeoLoad! Thanks to the NeoLoad monitoring modules’ exclusive technology, you don’t have to install anything on the servers you want to monitor! Using the standards already available on each platform, we remotely retrieve data, from basic system information up to detailed JMX data for a J2EE server for example.

This avoids disrupting your on-line system and the analysis of the test data is performed directly in NeoLoad!