You can also make k6 output detailed statistics in JSON format by using the --out/-o option for k6 run, like this:
$ k6 run --out json=my_test_result.json script.jsJSON format
The JSON file will contain lines like these:
{"type":"Metric","data":{"type":"gauge","contains":"default","tainted":null,"thresholds":[],"submetrics":null},"metric":"vus"}
{"type":"Point","data":{"time":"2017-05-09T14:34:45.625742514+02:00","value":5,"tags":null},"metric":"vus"}
{"type":"Metric","data":{"type":"trend","contains":"time","tainted":null,"thresholds":["avg\u003c1000"],"submetrics":null},"metric":"http_req_duration"}
{"type":"Point","data":{"time":"2017-05-09T14:34:45.239531499+02:00","value":459.865729,"tags":{"group":"::my group::json","method":"GET","status":"200","url":"https://httpbin.org/get"}},"metric":"http_req_duration"}Each line will either contain information about a metric, or log a data point (sample) for a metric. Lines consist of three items:
type- can have the values Metric or Point whereMetricmeans the line is declaring a metric, andPointis an actual data point (sample) for a metric.data- is a dictionary that contains lots of stuff, varying depending on the"type"above.metric- the name of the metric.
Metric
This line contains information about the nature of a metric. Here, "data" will contain the following:
"type"- the metric type ("gauge", "rate", "counter" or "trend")"contains"- information on the type of data collected (can e.g. be "time" for timing metrics)"tainted"- has this metric caused a threshold to fail?"threshold"- are there any thresholds attached to this metric?"submetrics"- any derived metrics created as a result of adding a threshold using tags.
Point
This line contains actual data samples. Here, "data" will contain these fields:
"time"- timestamp when the sample was collected"value"- the actual data sample; time values are in milliseconds"tags"- dictionary with tagname-tagvalue pairs that can be used when filtering results data
Processing JSON output
We recommend using jq to process the k6 JSON output. jq is a lightweight and flexible command-line JSON processor.
You can quickly create filters to return a particular metric of the JSON file:
$ jq '. | select(.type=="Point" and .metric == "http_req_duration" and .data.tags.status >= "200")' myscript-output.jsonAnd calculate an aggregated value of any metric:
$ jq '. | select(.type=="Point" and .metric == "http_req_duration" and .data.tags.status >= "200") | .data.value' myscript-output.json | jq -s 'add/length'$ jq '. | select(.type=="Point" and .metric == "http_req_duration" and .data.tags.status >= "200") | .data.value' myscript-output.json | jq -s min$ jq '. | select(.type=="Point" and .metric == "http_req_duration" and .data.tags.status >= "200") | .data.value' myscript-output.json | jq -s maxFor more advanced cases, check out the jq Manual
Summary export
New in v0.26.0
The --summary-export option of the k6 run command can export the end-of-test summary report to a JSON file that includes data for all test metrics, checks and thresholds.
This is useful to get the aggregated test results in a machine-readable format, for integration with dashboards, external alerts, etc.
$ k6 run --summary-export=export.json script.js# you can use the `summary-export` option with other output (Kafka, Datadog, Cloud, InfluxDB, JSON...)
$ k6 run --summary-export=export.json --out datadog script.jsThe format of the summary is like:
{
"metrics": {
"checks": {
"fails": 0,
"passes": 434,
"value": 0
},
"data_received": {
"count": 4267088,
"rate": 213353.42114517145
},
"data_sent": {
"count": 33726,
"rate": 1686.2922633754104
},
"http_req_blocked": {
"avg": 2.2303510806451645,
"max": 466.009823,
"med": 0.006873000000000001,
"min": 0.001265,
"p(90)": 0.0093969,
"p(95)": 0.01104339999999999
},
"http_req_connecting": {
"avg": 1.4719108986175116,
"max": 176.017402,
"med": 0,
"min": 0,
"p(90)": 0,
"p(95)": 0
},
"http_req_duration": {
"avg": 146.13434929493093,
"max": 663.812323,
"med": 115.237707,
"min": 104.336176,
"p(90)": 204.6849077,
"p(95)": 205.27533795
},
"http_req_receiving": {
"avg": 0.32699811981566856,
"max": 5.86652,
"med": 0.135682,
"min": 0.026588,
"p(90)": 1.4118543,
"p(95)": 1.6629313999999984
},
"http_req_sending": {
"avg": 0.031275672811059876,
"max": 0.149365,
"med": 0.028853,
"min": 0.006069,
"p(90)": 0.041769099999999997,
"p(95)": 0.05106769999999998
},
"http_req_tls_handshaking": {
"avg": 0,
"max": 0,
"med": 0,
"min": 0,
"p(90)": 0,
"p(95)": 0
},
"http_req_waiting": {
"avg": 145.77607550230408,
"max": 663.551133,
"med": 114.90324000000001,
"min": 103.389659,
"p(90)": 204.4926965,
"p(95)": 205.02902265
},
"http_reqs": {
"count": 434,
"rate": 21.699900441941768
},
"iteration_duration": {
"avg": 148.59040099078345,
"max": 671.970894,
"med": 115.69334950000001,
"min": 104.558313,
"p(90)": 205.0391277,
"p(95)": 209.87447475000002
},
"iterations": {
"count": 434,
"rate": 21.699900441941768
},
"vus": {
"max": 5,
"min": 1,
"value": 1
},
"vus_max": {
"max": 5,
"min": 5,
"value": 5
}
},
"root_group": {
"name": "",
"path": "",
"id": "d41d8cd98f00b204e9800998ecf8427e",
"groups": {},
"checks": {
"status is 200": {
"name": "status is 200",
"path": "::status is 200",
"id": "6210a8cd14cd70477eba5c5e4cb3fb5f",
"passes": 435,
"fails": 0
}
}
}
}