Caution
Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.
Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
prometheus.scrape
prometheus.scrape
configures a Prometheus scraping job for a given set of
targets
. The scraped metrics are forwarded to the list of receivers passed in
forward_to
.
Multiple prometheus.scrape
components can be specified by giving them
different labels.
Usage
prometheus.scrape "LABEL" {
targets = TARGET_LIST
forward_to = RECEIVER_LIST
}
Arguments
The component configures and starts a new scrape job to scrape all the input targets. The list of arguments that can be used to configure the block is presented below.
The scrape job name defaults to the component’s unique identifier.
Any omitted fields take on their default values. In case that conflicting attributes are being passed (e.g. defining both a BearerToken and BearerTokenFile or configuring both Basic Authorization and OAuth2 at the same time), the component reports an error.
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
targets | list(map(string)) | List of targets to scrape. | yes | |
forward_to | list(MetricsReceiver) | List of receivers to send scraped metrics to. | yes | |
job_name | string | The value to use for the job label if not already set. | component name | no |
extra_metrics | bool | Whether extra metrics should be generated for scrape targets. | false | no |
enable_protobuf_negotiation | bool | Whether to enable protobuf negotiation with the client. | false | no |
honor_labels | bool | Indicator whether the scraped metrics should remain unmodified. | false | no |
honor_timestamps | bool | Indicator whether the scraped timestamps should be respected. | true | no |
track_timestamps_staleness | bool | Indicator whether to track the staleness of the scraped timestamps. | false | no |
params | map(list(string)) | A set of query parameters with which the target is scraped. | no | |
scrape_classic_histograms | bool | Whether to scrape a classic histogram that is also exposed as a native histogram. | false | no |
scrape_interval | duration | How frequently to scrape the targets of this scrape configuration. | "60s" | no |
scrape_timeout | duration | The timeout for scraping targets of this configuration. | "10s" | no |
metrics_path | string | The HTTP resource path on which to fetch metrics from targets. | /metrics | no |
scheme | string | The URL scheme with which to fetch metrics from targets. | no | |
body_size_limit | int | An uncompressed response body larger than this many bytes causes the scrape to fail. 0 means no limit. | no | |
sample_limit | uint | More than this many samples post metric-relabeling causes the scrape to fail | no | |
target_limit | uint | More than this many targets after the target relabeling causes the scrapes to fail. | no | |
label_limit | uint | More than this many labels post metric-relabeling causes the scrape to fail. | no | |
label_name_length_limit | uint | More than this label name length post metric-relabeling causes the scrape to fail. | no | |
label_value_length_limit | uint | More than this label value length post metric-relabeling causes the scrape to fail. | no | |
bearer_token_file | string | File containing a bearer token to authenticate with. | no | |
bearer_token | secret | Bearer token to authenticate with. | no | |
enable_http2 | bool | Whether HTTP2 is supported for requests. | true | no |
follow_redirects | bool | Whether redirects returned by the server should be followed. | true | no |
proxy_url | string | HTTP proxy to send requests through. | no | |
no_proxy | string | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. | no | |
proxy_from_environment | bool | Use the proxy URL indicated by environment variables. | false | no |
proxy_connect_header | map(list(secret)) | Specifies headers to send to proxies during CONNECT requests. | no |
At most, one of the following can be provided:
no_proxy
can contain IPs, CIDR notations, and domain names. IP and domain
names can contain port numbers. proxy_url
must be configured if no_proxy
is configured.
proxy_from_environment
uses the environment variables HTTP_PROXY, HTTPS_PROXY
and NO_PROXY (or the lowercase versions thereof). Requests use the proxy from
the environment variable matching their scheme, unless excluded by NO_PROXY.
proxy_url
and no_proxy
must not be configured if proxy_from_environment
is configured.
proxy_connect_header
should only be configured if proxy_url
or proxy_from_environment
are configured.
track_timestamps_staleness
controls whether Prometheus tracks staleness of metrics which with an explicit timestamp present in scraped data.
- An “explicit timestamp” is an optional timestamp in the Prometheus metrics exposition format. For example, this sample has a timestamp of
1395066363000
:http_requests_total{method="post",code="200"} 1027 1395066363000
- If
track_timestamps_staleness
is set totrue
, a staleness marker will be inserted when a metric is no longer present or the target is down. - A “staleness marker” is just a sample with a specific NaN value which is reserved for internal use by Prometheus.
- It is recommended to set
track_timestamps_staleness
totrue
if the database where metrics are written to has enabled out of order ingestion. - If
track_timestamps_staleness
is set tofalse
, samples with explicit timestamps will only be labeled as stale after a certain time period, which in Prometheus is 5 minutes by default.
Blocks
The following blocks are supported inside the definition of prometheus.scrape
:
Hierarchy | Block | Description | Required |
---|---|---|---|
basic_auth | basic_auth | Configure basic_auth for authenticating to targets. | no |
authorization | authorization | Configure generic authorization to targets. | no |
oauth2 | oauth2 | Configure OAuth2 for authenticating to targets. | no |
oauth2 > tls_config | tls_config | Configure TLS settings for connecting to targets via OAuth2. | no |
tls_config | tls_config | Configure TLS settings for connecting to targets. | no |
clustering | clustering | Configure the component for when the Agent is running in clustered mode. | no |
The >
symbol indicates deeper levels of nesting. For example,
oauth2 > tls_config
refers to a tls_config
block defined inside
an oauth2
block.
basic_auth block
Name | Type | Description | Default | Required |
---|---|---|---|---|
password_file | string | File containing the basic auth password. | no | |
password | secret | Basic auth password. | no | |
username | string | Basic auth username. | no |
password
and password_file
are mutually exclusive, and only one can be provided inside a basic_auth
block.
authorization block
Name | Type | Description | Default | Required |
---|---|---|---|---|
credentials_file | string | File containing the secret value. | no | |
credentials | secret | Secret value. | no | |
type | string | Authorization type, for example, “Bearer”. | no |
credential
and credentials_file
are mutually exclusive, and only one can be provided inside an authorization
block.
oauth2 block
Name | Type | Description | Default | Required |
---|---|---|---|---|
client_id | string | OAuth2 client ID. | no | |
client_secret_file | string | File containing the OAuth2 client secret. | no | |
client_secret | secret | OAuth2 client secret. | no | |
endpoint_params | map(string) | Optional parameters to append to the token URL. | no | |
proxy_url | string | HTTP proxy to send requests through. | no | |
no_proxy | string | Comma-separated list of IP addresses, CIDR notations, and domain names to exclude from proxying. | no | |
proxy_from_environment | bool | Use the proxy URL indicated by environment variables. | false | no |
proxy_connect_header | map(list(secret)) | Specifies headers to send to proxies during CONNECT requests. | no | |
scopes | list(string) | List of scopes to authenticate with. | no | |
token_url | string | URL to fetch the token from. | no |
client_secret
and client_secret_file
are mutually exclusive, and only one can be provided inside an oauth2
block.
The oauth2
block may also contain a separate tls_config
sub-block.
no_proxy
can contain IPs, CIDR notations, and domain names. IP and domain
names can contain port numbers. proxy_url
must be configured if no_proxy
is configured.
proxy_from_environment
uses the environment variables HTTP_PROXY, HTTPS_PROXY
and NO_PROXY (or the lowercase versions thereof). Requests use the proxy from
the environment variable matching their scheme, unless excluded by NO_PROXY.
proxy_url
and no_proxy
must not be configured if proxy_from_environment
is configured.
proxy_connect_header
should only be configured if proxy_url
or proxy_from_environment
are configured.
tls_config block
Name | Type | Description | Default | Required |
---|---|---|---|---|
ca_pem | string | CA PEM-encoded text to validate the server with. | no | |
ca_file | string | CA certificate to validate the server with. | no | |
cert_pem | string | Certificate PEM-encoded text for client authentication. | no | |
cert_file | string | Certificate file for client authentication. | no | |
insecure_skip_verify | bool | Disables validation of the server certificate. | no | |
key_file | string | Key file for client authentication. | no | |
key_pem | secret | Key PEM-encoded text for client authentication. | no | |
min_version | string | Minimum acceptable TLS version. | no | |
server_name | string | ServerName extension to indicate the name of the server. | no |
The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:
ca_pem
andca_file
cert_pem
andcert_file
key_pem
andkey_file
When configuring client authentication, both the client certificate (using
cert_pem
or cert_file
) and the client key (using key_pem
or key_file
)
must be provided.
When min_version
is not provided, the minimum acceptable TLS version is
inherited from Go’s default minimum version, TLS 1.2. If min_version
is
provided, it must be set to one of the following strings:
"TLS10"
(TLS 1.0)"TLS11"
(TLS 1.1)"TLS12"
(TLS 1.2)"TLS13"
(TLS 1.3)
clustering block
Name | Type | Description | Default | Required |
---|---|---|---|---|
enabled | bool | Enables sharing targets with other cluster nodes. | false | yes |
When Grafana Agent Flow is using clustering, and enabled
is set to true,
then this prometheus.scrape
component instance opts-in to participating in
the cluster to distribute scrape load between all cluster nodes.
Clustering assumes that all cluster nodes are running with the same
configuration file, have access to the same service discovery APIs and that all
prometheus.scrape
components that have opted-in to using clustering, over
the course of a scrape interval, are converging on the same target set from
upstream components in their targets
argument.
All prometheus.scrape
components instances opting in to clustering use target
labels and a consistent hashing algorithm to determine ownership for each of
the targets between the cluster peers. Then, each peer only scrapes the subset
of targets that it is responsible for, so that the scrape load is distributed.
When a node joins or leaves the cluster, every peer recalculates ownership and
continues scraping with the new target set. This performs better than hashmod
sharding where all nodes have to be re-distributed, as only 1/N of the
targets ownership is transferred, but is eventually consistent (rather than
fully consistent like hashmod sharding is).
If Grafana Agent Flow is not running in clustered mode, then the block is a no-op and
prometheus.scrape
scrapes every target it receives in its arguments.
Exported fields
prometheus.scrape
does not export any fields that can be referenced by other
components.
Component health
prometheus.scrape
is only reported as unhealthy if given an invalid
configuration.
Debug information
prometheus.scrape
reports the status of the last scrape for each configured
scrape job on the component’s debug endpoint.
Debug metrics
agent_prometheus_fanout_latency
(histogram): Write latency for sending to direct and indirect components.agent_prometheus_scrape_targets_gauge
(gauge): Number of targets this component is configured to scrape.agent_prometheus_forwarded_samples_total
(counter): Total number of samples sent to downstream components.
Scraping behavior
The prometheus.scrape
component borrows the scraping behavior of Prometheus.
Prometheus, and by extent this component, uses a pull model for scraping
metrics from a given set of targets.
Each scrape target is defined as a set of key-value pairs called labels.
The set of targets can either be static, or dynamically provided periodically
by a service discovery component such as discovery.kubernetes
. The special
label __address__
must always be present and corresponds to the
<host>:<port>
that is used for the scrape request.
By default, the scrape job tries to scrape all available targets’ /metrics
endpoints using HTTP, with a scrape interval of 1 minute and scrape timeout of
10 seconds. The metrics path, protocol scheme, scrape interval and timeout,
query parameters, as well as any other settings can be configured using the
component’s arguments.
If a target is hosted at the in-memory traffic address specified by the
run command, prometheus.scrape
will scrape the metrics in-memory,
bypassing the network.
The scrape job expects the metrics exposed by the endpoint to follow the
OpenMetrics format. All metrics are then propagated
to each receiver listed in the component’s forward_to
argument.
Labels coming from targets, that start with a double underscore __
are
treated as internal, and are removed prior to scraping.
The prometheus.scrape
component regards a scrape as successful if it
responded with an HTTP 200 OK
status code and returned a body of valid
metrics.
If the scrape request fails, the component’s debug UI section contains more detailed information about the failure, the last successful scrape, as well as the labels last used for scraping.
The following labels are automatically injected to the scraped time series and can help pin down a scrape target.
Label | Description |
---|---|
job | The configured job name that the target belongs to. Defaults to the fully formed component name. |
instance | The __address__ or <host>:<port> of the scrape target’s URL. |
Similarly, these metrics that record the behavior of the scrape targets are also automatically available.
Metric Name | Description |
---|---|
up | 1 if the instance is healthy and reachable, or 0 if the scrape failed. |
scrape_duration_seconds | Duration of the scrape in seconds. |
scrape_samples_scraped | The number of samples the target exposed. |
scrape_samples_post_metric_relabeling | The number of samples remaining after metric relabeling was applied. |
scrape_series_added | The approximate number of new series in this scrape. |
scrape_timeout_seconds | The configured scrape timeout for a target. Useful for measuring how close a target was to timing out using scrape_duration_seconds / scrape_timeout_seconds |
scrape_sample_limit | The configured sample limit for a target. Useful for measuring how close a target was to reaching the sample limit using scrape_samples_post_metric_relabeling / (scrape_sample_limit > 0) |
scrape_body_size_bytes | The uncompressed size of the most recent scrape response, if successful. Scrapes failing because the body_size_limit is exceeded report -1, other scrape failures report 0. |
The up
metric is particularly useful for monitoring and alerting on the
health of a scrape job. It is set to 0
in case anything goes wrong with the
scrape target, either because it is not reachable, because the connection
times out while scraping, or because the samples from the target could not be
processed. When the target is behaving normally, the up
metric is set to
1
.
To enable scraping of Prometheus’ native histograms over gRPC, the
enable_protobuf_negotiation
must be set to true. The
scrape_classic_histograms
argument controls whether the component should also
scrape the ‘classic’ histogram equivalent of a native histogram, if it is
present.
Example
The following example sets up the scrape job with certain attributes (scrape endpoint, scrape interval, query parameters) and lets it scrape two instances of the blackbox exporter. The exposed metrics are sent over to the provided list of receivers, as defined by other components.
prometheus.scrape "blackbox_scraper" {
targets = [
{"__address__" = "blackbox-exporter:9115", "instance" = "one"},
{"__address__" = "blackbox-exporter:9116", "instance" = "two"},
]
forward_to = [prometheus.remote_write.grafanacloud.receiver, prometheus.remote_write.onprem.receiver]
scrape_interval = "10s"
params = { "target" = ["grafana.com"], "module" = ["http_2xx"] }
metrics_path = "/probe"
}
Here are the endpoints that are being scraped every 10 seconds:
http://blackbox-exporter:9115/probe?target=grafana.com&module=http_2xx
http://blackbox-exporter:9116/probe?target=grafana.com&module=http_2xx
Technical details
prometheus.scrape
supports gzip compression.
The following special labels can change the behavior of prometheus.scrape:
__address__
is the name of the label that holds the<host>:<port>
address of a scrape target.__metrics_path__
is the name of the label that holds the path on which to scrape a target.__scheme__
is the name of the label that holds the scheme (http,https) on which to scrape a target.__scrape_interval__
is the name of the label that holds the scrape interval used to scrape a target.__scrape_timeout__
is the name of the label that holds the scrape timeout used to scrape a target.__param_<name>
is a prefix for labels that provide URL parameters<name>
used to scrape a target.
Special labels added after a scrape
__name__
is the label name indicating the metric name of a timeseries.job
is the label name indicating the job from which a timeseries was scraped.instance
is the label name used for the instance label.
Compatible components
prometheus.scrape
can accept arguments from the following components:
- Components that export Targets
- Components that export Prometheus
MetricsReceiver
Note
Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.