{"id":111,"date":"2004-03-21T12:57:32","date_gmt":"2004-03-21T18:57:32","guid":{"rendered":"http:\/\/www.mooreds.com\/wordpress\/?p=111"},"modified":"2004-03-21T12:57:32","modified_gmt":"2004-03-21T18:57:32","slug":"the-grinder","status":"publish","type":"post","link":"https:\/\/www.mooreds.com\/wordpress\/archives\/111","title":{"rendered":"The Grinder"},"content":{"rendered":"

I did some performance testing against a web application that I helped write this weekend. I used The Grinder<\/a> and was quite happy with the beta version. This lets you write scripts in Jython<\/a> and uses the quite nice HTTPClient<\/a> library. The Grinder, like most other performance tools, has an admin interface (the console) and a set up distributed agents that are given tasks and communicate results back via the network to the console. I used the HTTP client, but it looks like you can ‘grind’ anything you can talk to via java, from databases<\/a> to email servers<\/a>.<\/p>\n

I did run into a few problems. I’m using cygwin<\/a> on WinXP, and had some difficulties running java from the command line. The fix was to use the cygpath command, like so:<\/p>\n

#!\/bin\/sh
\n# to start the agent
\nJAVA=\/cygdrive\/c\/j2sdk1.4.2_03\/bin\/java
\nCLASSPATH=`cygpath -p -w \/home\/Owner\/work\/grinder\/grinder-3.0-beta20\/lib\/grinder.jar:\\
\n\/home\/Owner\/work\/grinder\/grinder-3.0-beta20\/lib\/jakarta-oro-2.0.6.jar:\\
\n\/home\/Owner\/work\/grinder\/grinder-3.0-beta20\/lib\/jython.jar`
\n$JAVA -cp $CLASSPATH net.grinder.Grinder
\n<\/code><\/p>\n

The client application that I was testing doesn’t use cookies (it’s a J2ME application, and the MIDP spec<\/a> doesn’t support cookies out of the box<\/a>). Or rather, it uses cookies, but only to grab the first one that the server sends, store it off, and then pass it back as a query parameter. This type of configuration isn’t The Grinder’s sweet spot, and I had to do a bit of hacking to make sure the appropriate cookie value was sent with the appropriate client request. It would have been nice to use contexts<\/a> but The Grinder wraps the HTTPConnection in its own class. Apparently, if you are simulating use by a browser, cookies are apparently handled correctly<\/a>. One gripe–there’s no javadoc for the main classes available on The Grinder’s website<\/a>, so you have to grab the source<\/a> if you want to see interactions between pieces (for example, how net.grinder.plugin.http.HTTPRequest<\/code> interacts with HTTPClient.HTTPConnection<\/a><\/code>).<\/p>\n

I also mucked with some of the properties, primarily initialSleepTime<\/a>. You’ll want to make sure that you read about these properties–I blithely uncommented what was in the sample grinder.properties and ended up with an obscene value for grinder.sleepTimeFactor<\/a>.<\/p>\n

After all the setup, I was able to hammer our server. I discovered two useful things: an error in our logout code, which threw exceptions around 10% of the time, and also discovered that our connection timeout <\/a> between Apache and Tomcat was set incorrectly. Changing this from 0 to 1000 fixed the dreaded SEVERE: All threads are busy, waiting. Please increase maxThreads or check the servlet status<\/code> error that I was getting. In addition to these two useful bugs, by making some assumptions about how the application will be used, I was able to gimmick up<\/a> some interesting numbers about supportable users.<\/p>\n

I like The Grinder a fair bit. It’s got a nice GUI. It’s still under active development. I’m a bit leery of using beta software (especially open source beta software), but a poll<\/a> on the homepage convinced me to try the beta. By using this, I was also able to pick up snatches of python<\/a> which is a new language to me (finally got to consult my long unused copy of Learning Python<\/a>). I considered looking at JMeter<\/a>, but The Grinder appears to be a bit more recently maintained<\/a>. It’s no LoadRunner<\/a>, but then again, it doesn’t pretend to be<\/a>. All in all, if you’re in the market for a cheap, quick performance tool, The Grinder is worth a look.<\/p>\n","protected":false},"excerpt":{"rendered":"

I did some performance testing against a web application that I helped write this weekend. I used The Grinder and was quite happy with the beta version. This lets you […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,6],"tags":[],"class_list":["post-111","post","type-post","status-publish","format-standard","hentry","category-java","category-programming"],"_links":{"self":[{"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/posts\/111","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/comments?post=111"}],"version-history":[{"count":1,"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/posts\/111\/revisions"}],"predecessor-version":[{"id":631,"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/posts\/111\/revisions\/631"}],"wp:attachment":[{"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/media?parent=111"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/categories?post=111"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mooreds.com\/wordpress\/wp-json\/wp\/v2\/tags?post=111"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}