Scenario Log

Goose can optionally log details about each time a scenario is run during a load test. To enable, add the --scenario-log <scenario.log> command line option, where <scenario.log> is either a relative or absolute path of the log file to create. Any existing file that may already exist will be overwritten.

Logs include the entire ScenarioMetric object which is created each time any scenario is run.

Log Format

By default, logs are written in JSON Lines format. For example:

{"elapsed":20926,"name":"WebsiteUser","index":0,"run_time":20756,"user":1,"run_time_fraction_us":471}
{"elapsed":21402,"name":"WebsiteUser","index":0,"run_time":21064,"user":2,"run_time_fraction_us":471}
{"elapsed":22791,"name":"WebsiteUser","index":0,"run_time":22285,"user":3,"run_time_fraction_us":334}
{"elapsed":24811,"name":"WebsiteUser","index":0,"run_time":24810,"user":0,"run_time_fraction_us":432}

These lines are from the simple example. In the first line, GooseUser thread 1 ran the complete WebsiteUser scenario in 20,756.471 milliseconds, which includes the wait after each transaction. In the fourth line, GooseUser thread 0 ran it in 24,810.432 milliseconds.

The --scenario-format option can be used to log in csv, json (default), raw or pretty format. The raw format is Rust’s debug output of the entire ScenarioMetric object, one per line, and pretty is the same output spread over several indented lines per scenario run.

For example, csv output of the same example starts with a header row and looks like:

elapsed,name,index,run_time,user,run_time_us
19283,WebsiteUser,0,18945,2,18945361
19724,WebsiteUser,0,18882,5,18882239
20468,WebsiteUser,0,20467,0,20467323
24027,WebsiteUser,0,23857,1,23857874

run_time is in whole milliseconds, truncated. The json, raw and pretty formats also carry run_time_fraction_us, the microseconds past those milliseconds (0 to 999), and the csv format ends with a run_time_us column holding the whole time in microseconds.