The Grinder – An open source Performance testing alternative

Posted by Arun Shanmugam
February 21st, 2012

Owing to the cut throat competition, IT companies are striving to go one step ahead than their competitors to woo their prospective clients. Cutting down the costs without compromising on the quality has been the effective strategy these days. Open source tools not only promise to cut down the costs drastically, but are also more flexible and provide certain unique features of their own. The huge expense involved in procuring performance testing tools has urged the testing community to look for an open source alternative that would go easy on the budget.

The Grinder is an open source performance testing tool originally developed by Paco Gomez and Peter Zadrozny. The Grinder is a JavaTM load testing framework that makes it easy to run a distributed test using many load injector machines.

1.1          Why Grinder?

  • The Grinder can be a viable open source option for performance testing.It is freely available under a BSD-style open-source license that can be downloaded from
  • The test scripts are written in simple and flexible Jython language which makes it very powerful and flexible. As it is an implementation of the Python programming language written in Java, all of the advantages of Java are also inherent here. No separate plug-ins or libraries are required
  • The Grinder makes use of a powerful distributed Java load testing framework that allows simulation of multiple user loads across different “agents” which can be managed by a centralized controller or “console”. From this console you can edit the test scripts and distribute them to the worker processes as per the requirement
  • It is a surprisingly lightweight tool, fairly easy to set up and run and it takes almost no time at all to get started. The installation simply involves downloading and configuring the recorder, console and agent batch files.The Grinder 3  is distributed as two zip files. The grinder properties file can be customized to suit our requirement, each time we execute a test
  • From a developer’s point of view, Grinder is the preferred load testing tool wherein the developers can opt to test their own application. I.e. The programmers get to test the interior tiers of their own application
  • The Grinder tool has a strong support base in the form of mailing lists i.e.
  • The Grinder tool has excellent compatibility with Grinder Analyzer which is also available as an open source license. The analyzer extracts data from grinder log and generates report and graphs containing response time, transactions per second, and network bandwidth used
  • Other than HTTP and HTTPS, The Grinder does support internet protocols such as POP3, SMTP, FTP, and LDAP

1.2          Difficulties that should be considered before opting for the Grinder

  • No user friendly interface is provided for coding, scripting(parameterization, correlation, Inserting custom functions etc) and other enhancements at the test script preparation level
  • Annoying syntax errors do creep in into the coding part due to the rigid syntax and indentation required at the coding level as Jython scripting is used
  • A lot depends on the tester’s ability to understand the interior tiers of the application unlike other commercial tools  where the tester can blindly follow the standard procedures without any insight into the intricate complexity of the application and can still succeed in completing his job successfully
  • It is dependent on Grinder Analyzer for analysis, report generation etc
  • The protocols supported by the Grinder are limited, whereas commercial tools such as LoadRunner, Silk Performer provides support for all the web based protocols. This is one major limiting factor as the web based applications these days use multi protocols for communication.
  • Unlike LoadRunner and other vendor licensed tools, it does not offer effective monitoring solutions and in-depth diagnostic capabilities. Also there is no separate user friendly interface component dedicated for analyzing the test results
  • More support is required in the form of forums, blogs and user communities

In short Tom Braverman sums it up brilliantly in a post to the Grinder use,

“I don’t try and persuade my clients that The Grinder is a replacement for LoadRunner, etc. I tell them that The Grinder is for use by the developers and that they’ll still want the QA team to generate scalability metrics using LoadRunner or some other tool approved for the purpose by management”

For an open source testing tool, it has to be admitted that the Grinder does have the capabilities feature wise to make a stand amidst other commercial alternatives.

Comments (0)