Tip 5 – Logging made easy

Generally speaking it is useful to write your logs to file when running tests. This will help reproduce your results later on, make life easy with comparing results of different tests and will serve as a useful audit log for your load report later on.
The easy way to save the log is to add a filename string in the “Write results to file” box of your listener like this:

As you can see in this example I generally specify the logname to be at least a bit meaningful, e.g. which Listener did I use and how many threads did I start (the latter is not visible in this sample).

You do however quite regularly run the same amount of threads more than once, so how do you make clear which run this was? Updating the filename very quickly becomes an nuisance. So why not automate that?

I generally use the ${__time()} function. Making the filename something like this:

${__time(yyyyMMdd-HHmmss)}-LISTENERNAME-NUMBEROFTHREADS.jtl

This kind of logging results in a set of files which is easily sortable on filename and easily readable based on the amount of threads started for this particular test:

20160404-103706-resultsInTable-10threads.jtl