The Vector prometheus_exporter sink exposes metrics

Warnings

• High cardinality metric names and labels are discouraged by Prometheus as they can provide performance and reliability problems. You should consider alternative strategies to reduce the cardinality. Vector offers a tag_cardinality_limit transform as a way to protect against this.

Configuration

• Common
• Advanced

• vector.toml
• vector.yaml
• vector.json

[sinks.my_sink_id]
  type = "prometheus_exporter" # required
  inputs = ["my-source-or-transform-id", "prefix-*"] # required
  address = "0.0.0.0:9598" # required
  default_namespace = "service" # optional, no default

5 items

commonrequired

• commonrequiredstring

  address

  The address to expose for scraping.

  • Syntax: literal
  • View examples
• optional[float]

  buckets

  Default buckets to use for aggregating distribution metrics into histograms. See Histogram Buckets for more info.

  • Default: [0.005,0.01,0.025,0.05,0.1,0.25,0.5,1,2.5,5,10]
  • View examples
• commonoptionalstring

  default_namespace

  Used as a namespace for metrics that don't have it. Typically namespaces are set during ingestion (sources), but it is optional and when missing, we'll use this value. It should follow Prometheus naming conventions.

  • Syntax: literal
  • View examples
• optionaluint

  flush_period_secs

  Time interval between set values are reset.

  • Default: 60 (seconds)
• optional[float]

  quantiles

  Quantiles to use for aggregating distribution metrics into a summary.

  • Default: [0.5,0.75,0.9,0.95,0.99]
  • View examples

Telemetry

This component provides the following metrics that can be retrieved through the internal_metrics source. See the metrics section in the monitoring page for more info.

• counter

  events_in_total

  The total number of events accepted by this component. This metric includes the following tags:

  • component_kind - The Vector component kind.

  • component_name - The Vector component ID.

  • component_type - The Vector component type.

  • instance - The Vector instance identified by host and port.

  • job - The name of the job producing Vector metrics.

• counter

  events_out_total

  The total number of events emitted by this component. This metric includes the following tags:

  • component_kind - The Vector component kind.

  • component_name - The Vector component ID.

  • component_type - The Vector component type.

  • instance - The Vector instance identified by host and port.

  • job - The name of the job producing Vector metrics.

Examples

Counter

Given the following Vector metric event:

{
  "kind": "incremental",
  "name": "logins",
  "counter": {
    "value": 1.5
  },
  "tags": {
    "host": "my-host.local"
  }
}

And the following configuration:

vector.toml

[sinks.prometheus_exporter]
type = "prometheus_exporter"
default_namespace = "service"

The following output will be produced:

HELP service_logins logins

TYPE service_logins counter

service_logins{host="my-host.local"} 1.5

How It Works

Histogram Buckets

Choosing the appropriate buckets for Prometheus histograms is a complicated point of discussion. The Histograms and Summaries Prometheus guide) provides a good overview of histograms, buckets, summaries, and how you should think about configuring them. The buckets you choose should align with your known range and distribution of values as well as how you plan to report on them. The aforementioned guide provides examples on how you should align them.

Default Buckets

The buckets option defines the global default buckets for histograms. These defaults are tailored to broadly measure the response time (in seconds) of a network service. Most likely, however, you will be required to define buckets customized to your use case.

Memory Usage

Like other Prometheus instances, the prometheus sink aggregates metrics in memory which keeps the memory footprint to a minimum if Prometheus fails to scrape the Vector instance over an extended period of time. The downside is that data will be lost if Vector is restarted. This is by design of Prometheus' pull model approach, but is worth noting if restart Vector frequently.

State

This component is stateful, meaning its behavior changes based on previous inputs (events). State is not preserved across restarts, therefore state-dependent behavior will reset between restarts and depend on the inputs (events) received since the most recent restart.