Request Log

Goose can optionally log details about all the requests made during the load test to a file. This log file contains the running metrics Goose generates as the load test runs. To enable, add the --request-log <request.log> command line option, where <request.log> is either a relative or absolute path of the log file to create. Any existing file that may already exist will be overwritten.

If --request-body is also enabled, the request log will include the entire body of any client requests, in the body field of the raw request.

Logs include the entire GooseRequestMetric object which also includes the entire GooseRawRequest object, both created for all client requests.

The headers field of the GooseRawRequest lists the headers set on the individual request (for example by .header(), .bearer_auth(), .json() or .form()); headers that Reqwest adds when it sends the request are not included: the client’s default headers (those set with .default_headers(), the User-Agent and Accept: */*), the Cookie header from the cookie store, Accept-Encoding when compression is enabled, and the Host and Content-Length headers. Reqwest offers no way to read them: https://github.com/tag1consulting/goose/issues/336. Request headers are only captured when the request log, the debug log or the error log is enabled, otherwise headers is empty.

Log Format

By default, logs are written in JSON Lines format. For example, from the simple example with --request-body also enabled:

{"elapsed":505,"scenario_index":0,"scenario_name":"websiteuser","transaction_index":0,"transaction_name":{"TransactionOnly":""},"raw":{"method":"Post","url":"http://127.0.0.1:8080/login","headers":["(\"content-type\", \"application/x-www-form-urlencoded\")"],"body":"username=test_user&password=","custom_method":""},"name":"/login","final_url":"http://127.0.0.1:8080/login","redirected":false,"response_time":1,"status_code":200,"success":true,"update":false,"user":3,"error":"","coordinated_omission_elapsed":0,"user_cadence":0,"response_time_fraction_us":221}
{"elapsed":506,"scenario_index":0,"scenario_name":"websiteuser","transaction_index":1,"transaction_name":{"TransactionOnly":""},"raw":{"method":"Get","url":"http://127.0.0.1:8080/","headers":[],"body":"","custom_method":""},"name":"/","final_url":"http://127.0.0.1:8080/","redirected":false,"response_time":1,"status_code":200,"success":true,"update":false,"user":3,"error":"","coordinated_omission_elapsed":0,"user_cadence":0,"response_time_fraction_us":202}
{"elapsed":6875,"scenario_index":0,"scenario_name":"websiteuser","transaction_index":2,"transaction_name":{"TransactionOnly":""},"raw":{"method":"Get","url":"http://127.0.0.1:8080/about/","headers":[],"body":"","custom_method":""},"name":"/about/","final_url":"http://127.0.0.1:8080/about/","redirected":false,"response_time":0,"status_code":200,"success":true,"update":false,"user":2,"error":"","coordinated_omission_elapsed":0,"user_cadence":0,"response_time_fraction_us":632}

The --request-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 GooseRequestMetric object, one per line, and pretty is the same output spread over several indented lines per request.

The csv format starts with a header row. Its transaction_name column holds the transaction’s name only when it was set with set_name_for_transaction_and_requests; a name set with set_name, or no name as in this example, leaves it empty, and its raw column holds the debug output of the GooseRawRequest. The first two requests of the same example look like:

elapsed,scenario_index,scenario_name,transaction_index,transaction_name,raw,name,final_url,redirected,response_time,status_code,success,update,user,error,coordinated_omission_elapsed,user_cadence,response_time_us
0,0,websiteuser,0,,"GooseRawRequest { method: Post, url: ""http://127.0.0.1:8080/login"", headers: [""(\""content-type\"", \""application/x-www-form-urlencoded\"")""], body: ""username=test_user&password="", custom_method: """" }",/login,http://127.0.0.1:8080/login,false,0,200,true,false,0,,0,0,756
0,0,websiteuser,1,,"GooseRawRequest { method: Get, url: ""http://127.0.0.1:8080/"", headers: [], body: """", custom_method: """" }",/,http://127.0.0.1:8080/,false,0,200,true,false,0,,0,0,188

The transaction_name field is an object naming how the transaction was named: {"TransactionOnly":"..."} for a name set with set_name, which only the transaction carries, or {"InheritNameByRequests":"..."} for a name set with set_name_for_transaction_and_requests, which its requests take too. Goose 0.18 wrote it as a plain string, and wrote the transaction’s name in the CSV column however it was set.

response_time is in whole milliseconds, truncated. The json, raw and pretty formats also carry response_time_fraction_us, the microseconds past those milliseconds (0 to 999), and the csv format ends with a response_time_us column holding the whole time in microseconds. In the first JSON line above the /login request took 1.221 milliseconds, and in the third the /about/ request took 632 microseconds. In the first CSV row the /login request took 756 microseconds.