docs-v2/content/flux/v0.x/query-data/prometheus.md

title	list_title	description	menu	weight	list_code_example	draft
Scrape Prometheus metrics	Prometheus	Use [`prometheus.scrape`](/flux/v0.x/stdlib/experimental/prometheus/scrape) to scrape Prometheus-formatted metrics from an HTTP-accessible endpoint using Flux.	flux_0_x name parent Prometheus Query data sources	104	```js import "experimental/prometheus" prometheus.scrape(url: "http://example.com/metrics") ```	true

To scrape Prometheus-formatted metrics from an HTTP-accessible endpoint using Flux:

1. Import the experimental/prometheus package.
2. Use prometheus.scrape. Use the url parameter to provide the URL to scrape metrics from.

{{< keep-url >}}

import "experimental/prometheus"

prometheus.scrape(url: "http://localhost:8086/metrics")

Results structure

prometheus.scrape() returns a stream of tables with the following columns:

• _time: Data timestamp
• _measurement: prometheus
• _field: Prometheus metric name
• _value: Prometheus metric value
• url: URL metrics were scraped from
• Label columns: A column for each Prometheus label. The column label is the label name and the column value is the label value.

Tables are grouped by _measurement, _field, and Label columns.

{{% note %}}

Columns with the underscore prefix

Columns with the underscore (_) prefix are considered "system" columns. Some Flux functions require these columns to function properly. {{% /note %}}

Example Prometheus query results

The following are example Prometheus metrics scraped from the InfluxDB OSS 2.x /metrics endpoint:

# HELP go_goroutines Number of goroutines that currently exist.
# TYPE go_goroutines gauge
go_goroutines 1263
# HELP go_info Information about the Go environment.
# TYPE go_info gauge
go_info{version="go1.16.3"} 1
# HELP go_memstats_alloc_bytes Number of bytes allocated and still in use.
# TYPE go_memstats_alloc_bytes gauge
go_memstats_alloc_bytes 2.6598832e+07
# HELP go_memstats_alloc_bytes_total Total number of bytes allocated, even if freed.
# TYPE go_memstats_alloc_bytes_total counter
go_memstats_alloc_bytes_total 1.42276424e+09
# HELP go_memstats_buck_hash_sys_bytes Number of bytes used by the profiling bucket hash table.
# TYPE go_memstats_buck_hash_sys_bytes gauge
go_memstats_buck_hash_sys_bytes 5.259247e+06

When scraped by Flux, these metrics return the following stream of tables:

_time	_measurement	_field	_value	url
2021-01-01T00:00:00Z	prometheus	go_goroutines	1263	http://localhost:8086/metrics

_time	_measurement	_field	_value	url	version
2021-01-01T00:00:00Z	prometheus	go_info	1	http://localhost:8086/metrics	go1.16.3

_time	_measurement	_field	_value	url
2021-01-01T00:00:00Z	prometheus	go_memstats_alloc_bytes	26598832	http://localhost:8086/metrics

_time	_measurement	_field	_value	url
2021-01-01T00:00:00Z	prometheus	go_memstats_alloc_bytes_total	1422764240	http://localhost:8086/metrics

_time	_measurement	_field	_value	url
2021-01-01T00:00:00Z	prometheus	go_memstats_buck_hash_sys_bytes	5259247	http://localhost:8086/metrics

{{% note %}}

Write Prometheus metrics to InfluxDB

To write scraped Prometheus metrics to InfluxDB:

1. Use prometheus.scrape() to scrape Prometheus metrics.
2. Use to() to write the scraped metrics to InfluxDB.

import "experimental/prometheus"
  
prometheus.scrape(url: "http://example.com/metrics")
  |> to(
    bucket: "example-bucket",
    host: "http://localhost:8086",
    org: "example-org",
    token: "mYsuP3R5eCR37t0K3n"  
  )

To scrape Prometheus metrics and write them to InfluxDB at regular intervals, use the example above to create an InfluxDB task. {{% /note %}}