A k6 extension implements Prometheus HTTP exporter as k6 output extension.
Using xk6-prometheus output extension you can collect metrics from long running k6 process with Prometheus. All custom k6 metrics (Counter,Gauge,Rate,Trend) and build-in metrics will be accessible as appropiate Prometheus metrics on a given HTTP port in Prometheus importable text format.
To build a k6 binary with this extension, first ensure you have the prerequisites:
- Go toolchain
- Git
Then:
- Download
xk6:
$ go get -u github.com/k6io/xk6- Build the binary:
$ xk6 build v0.31.1 --with github.com/szkiba/xk6-prometheusYou should use at least
v0.31.0version because xk6-prometheus extension registers itself as output extension. This feature introduced in thev0.31.0version of k6.
Without parameters the Prometheus HTTP exporter will accessible on port 5656.
$ ./k6 run -d 1m --out prometheus script.js
/\ |‾‾| /‾‾/ /‾‾/
/\ / \ | |/ / / /
/ \/ \ | ( / ‾‾\
/ \ | |\ \ | (‾) |
/ __________ \ |__| \__\ \_____/ .io
execution: local
script: script.js
output: prometheus (:5656)
scenarios: (100.00%) 1 scenario, 1 max VUs, 1m30s max duration (incl. graceful stop):
* default: 1 looping VUs for 1m0s (gracefulStop: 30s)
running (1m00.8s), 0/1 VUs, 54 complete and 0 interrupted iterations
default ✓ [======================================] 1 VUs 1m0s
data_received..................: 611 kB 10 kB/s
data_sent......................: 4.1 kB 67 B/s
http_req_blocked...............: avg=2.55ms min=4.05µs med=8.92µs max=137.67ms p(90)=12.7µs p(95)=13.15µs
http_req_connecting............: avg=2.19ms min=0s med=0s max=118.73ms p(90)=0s p(95)=0s
http_req_duration..............: avg=122.13ms min=119.31ms med=121.19ms max=139.75ms p(90)=123.43ms p(95)=126.27ms
{ expected_response:true }...: avg=122.13ms min=119.31ms med=121.19ms max=139.75ms p(90)=123.43ms p(95)=126.27ms
http_req_failed................: 0.00% ✓ 0 ✗ 54
http_req_receiving.............: avg=839.36µs min=610.96µs med=789.06µs max=3.89ms p(90)=847.57µs p(95)=881.74µs
http_req_sending...............: avg=46.16µs min=14.5µs med=40.56µs max=177.74µs p(90)=60.48µs p(95)=66.41µs
http_req_tls_handshaking.......: avg=0s min=0s med=0s max=0s p(90)=0s p(95)=0s
http_req_waiting...............: avg=121.24ms min=118.48ms med=120.31ms max=137.43ms p(90)=122.64ms p(95)=125.43ms
http_reqs......................: 54 0.888369/s
iteration_duration.............: avg=1.12s min=1.11s med=1.12s max=1.25s p(90)=1.12s p(95)=1.13s
iterations.....................: 54 0.888369/s
vus............................: 1 min=1 max=1
vus_max........................: 1 min=1 max=1
The output extension accept parameters in a standard query string format:
k6 run --out 'prometheus=param1=value1¶m2=value2¶m3=value3'
Note apostrophe (
') characters around the--outparameter! You should use it for escape&characters from shell (or use backslash before&characters).
The following paremeters are recognized:
| parameter | description |
|---|---|
| namespace | Prometheus namespace for exported metrics (default: "", empty) |
| subsystem | Prometheus subsystem for exported metrics (default: "", empty) |
| host | Hostname or IP address for HTTP endpoint (default: "", empty, listen on all interfaces) |
| port | TCP port for HTTP endoint (default: 5656) |
It is recommended to use k6 as either namespace or subsystem to prefix exported metrics names with k6_ string.
Here is the relevant part of the metrics HTTP response:
# HELP k6_data_received The amount of received data
# TYPE k6_data_received counter
k6_data_received 588452
# HELP k6_data_sent The amount of data sent
# TYPE k6_data_sent counter
k6_data_sent 3952
# HELP k6_http_req_blocked Time spent blocked before initiating the request
# TYPE k6_http_req_blocked summary
k6_http_req_blocked{quantile="0.5"} 0.008816
k6_http_req_blocked{quantile="0.9"} 0.012707
k6_http_req_blocked{quantile="0.95"} 0.012851
k6_http_req_blocked_sum 138.14527600000005
k6_http_req_blocked_count 52
# HELP k6_http_req_blocked_value Time spent blocked before initiating the request (value)
# TYPE k6_http_req_blocked_value gauge
k6_http_req_blocked_value 0.009559
# HELP k6_http_req_connecting Time spent establishing TCP connection
# TYPE k6_http_req_connecting summary
k6_http_req_connecting{quantile="0.5"} 0
k6_http_req_connecting{quantile="0.9"} 0
k6_http_req_connecting{quantile="0.95"} 0
k6_http_req_connecting_sum 118.737106
k6_http_req_connecting_count 52
# HELP k6_http_req_connecting_value Time spent establishing TCP connection (value)
# TYPE k6_http_req_connecting_value gauge
k6_http_req_connecting_value 0
# HELP k6_http_req_duration Total time for the request
# TYPE k6_http_req_duration summary
k6_http_req_duration{quantile="0.5"} 121.216566
k6_http_req_duration{quantile="0.9"} 123.535732
k6_http_req_duration{quantile="0.95"} 127.755531
k6_http_req_duration_sum 6354.830187
k6_http_req_duration_count 52
# HELP k6_http_req_duration_value Total time for the request (value)
# TYPE k6_http_req_duration_value gauge
k6_http_req_duration_value 120.766806
# HELP k6_http_req_failed The rate of failed requests
# TYPE k6_http_req_failed histogram
k6_http_req_failed_bucket{le="0"} 52
k6_http_req_failed_bucket{le="+Inf"} 52
k6_http_req_failed_sum 0
k6_http_req_failed_count 52
# HELP k6_http_req_receiving Time spent receiving response data
# TYPE k6_http_req_receiving summary
k6_http_req_receiving{quantile="0.5"} 0.787394
k6_http_req_receiving{quantile="0.9"} 0.847776
k6_http_req_receiving{quantile="0.95"} 0.882193
k6_http_req_receiving_sum 43.79441599999999
k6_http_req_receiving_count 52
# HELP k6_http_req_receiving_value Time spent receiving response data (value)
# TYPE k6_http_req_receiving_value gauge
k6_http_req_receiving_value 0.725954
# HELP k6_http_req_sending Time spent sending data
# TYPE k6_http_req_sending summary
k6_http_req_sending{quantile="0.5"} 0.040285
k6_http_req_sending{quantile="0.9"} 0.060527
k6_http_req_sending{quantile="0.95"} 0.067514
k6_http_req_sending_sum 2.394856
k6_http_req_sending_count 52
# HELP k6_http_req_sending_value Time spent sending data (value)
# TYPE k6_http_req_sending_value gauge
k6_http_req_sending_value 0.040846
# HELP k6_http_req_tls_handshaking Time spent handshaking TLS session
# TYPE k6_http_req_tls_handshaking summary
k6_http_req_tls_handshaking{quantile="0.5"} 0
k6_http_req_tls_handshaking{quantile="0.9"} 0
k6_http_req_tls_handshaking{quantile="0.95"} 0
k6_http_req_tls_handshaking_sum 0
k6_http_req_tls_handshaking_count 52
# HELP k6_http_req_tls_handshaking_value Time spent handshaking TLS session (value)
# TYPE k6_http_req_tls_handshaking_value gauge
k6_http_req_tls_handshaking_value 0
# HELP k6_http_req_waiting Time spent waiting for response
# TYPE k6_http_req_waiting summary
k6_http_req_waiting{quantile="0.5"} 120.329931
k6_http_req_waiting{quantile="0.9"} 122.741878
k6_http_req_waiting{quantile="0.95"} 126.89048
k6_http_req_waiting_sum 6308.640915000001
k6_http_req_waiting_count 52
# HELP k6_http_req_waiting_value Time spent waiting for response (value)
# TYPE k6_http_req_waiting_value gauge
k6_http_req_waiting_value 120.000006
# HELP k6_http_reqs How many HTTP requests has k6 generated, in total
# TYPE k6_http_reqs counter
k6_http_reqs 52
# HELP k6_iteration_duration The time it took to complete one full iteration
# TYPE k6_iteration_duration summary
k6_iteration_duration{quantile="0.5"} 1122.287172
k6_iteration_duration{quantile="0.9"} 1125.321538
k6_iteration_duration{quantile="0.95"} 1139.260684
k6_iteration_duration_sum 58539.15245099999
k6_iteration_duration_count 52
# HELP k6_iteration_duration_value The time it took to complete one full iteration (value)
# TYPE k6_iteration_duration_value gauge
k6_iteration_duration_value 1121.81436
# HELP k6_iterations The aggregate number of times the VUs in the test have executed
# TYPE k6_iterations counter
k6_iterations 52
# HELP k6_vus Current number of active virtual users
# TYPE k6_vus gauge
k6_vus 1
# HELP k6_vus_max Max possible number of virtual users
# TYPE k6_vus_max gauge
k6_vus_max 1