Prometheus Exporter

Output metric events to a Prometheus exporter running on the host

status: stable delivery: best effort acknowledgements: no egress: expose state: stateful previously known as: prometheus
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Alias

This component was previously called the prometheus sink. Make sure to update your Vector configuration to accommodate the name change:

[sinks.my_prometheus_exporter_sink]
+type = "prometheus_exporter"
-type = "prometheus"

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

Example configurations 

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ],
      "address": "0.0.0.0:9598",
      "default_namespace": "service"
    }
  }
}
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]
address = "0.0.0.0:9598"
default_namespace = "service"

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id
    address: 0.0.0.0:9598
    default_namespace: service

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ],
      "address": "0.0.0.0:9598",
      "buckets": [
        0.005
      ],
      "flush_period_secs": 60,
      "default_namespace": "service",
      "quantiles": [
        0.5
      ],
      "buffer": null,
      "tls": null,
      "distributions_as_summaries": null
    }
  }
}
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]
address = "0.0.0.0:9598"
buckets = [ 0.005 ]
flush_period_secs = 60
default_namespace = "service"
quantiles = [ 0.5 ]

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id
    address: 0.0.0.0:9598
    buckets:
      - 0.005
    flush_period_secs: 60
    default_namespace: service
    quantiles:
      - 0.5
    buffer: null
    tls: null
    distributions_as_summaries: null

address

required string literal
The address to expose for scraping. The metrics are exposed at the typical Prometheus exporter path, /metrics
Examples 
"0.0.0.0:9598"

buckets

optional [float]
Default buckets to use for aggregating distribution metrics into histograms.
Array float
Examples 
[
  0.005,
  0.01
]
default: [0.005 0.01 0.025 0.05 0.1 0.25 0.5 1 2.5 5 10]

buffer

optional object
Configures the sink specific buffer behavior.

buffer.max_events

common optional uint
The maximum number of events allowed in the buffer.
Relevant when: type = "memory"
default: 500 (events)

buffer.max_size

required uint

The maximum size of the buffer on the disk. Must be at least 128 megabytes (134217728 bytes).

Note that during normal disk buffer operation, the disk buffer can create one additional 128 megabyte block so the minimum disk space required is actually 256 megabytes.

Relevant when: type = "disk"
Examples 
104900000

buffer.type

common optional string literal enum
The buffer’s type and storage mechanism.
Enum options
OptionDescription
diskStores the sink’s buffer on disk. This is less performant, but durable. Data will not be lost between restarts. Will also hold data in memory to enhance performance. WARNING: This may stall the sink if disk performance isn’t on par with the throughput. For comparison, AWS gp2 volumes are usually too slow for common cases.
memoryStores the sink’s buffer in memory. This is more performant, but less durable. Data will be lost if Vector is restarted forcefully.
default: memory

buffer.when_full

optional string literal enum
The behavior when the buffer becomes full.
Enum options
OptionDescription
blockApplies back pressure when the buffer is full. This prevents data loss, but will cause data to pile up on the edge.
drop_newestDrops new data as it’s received. This data is lost. This should be used when performance is the highest priority.
default: block

default_namespace

common optional string literal
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.
Examples 
"service"

distributions_as_summaries

optional bool
Whether or not to render distributions as a histogram or summary, which map one-to-one with the Prometheus metric types of the same name.
default: false

flush_period_secs

optional uint
Time interval on which metrics are flushed. On the flush interval, if a metric has not been seen since the last flush interval, it is considered expired and is removed. Be sure to configure this value higher than your client’s scrape interval.
default: 60 (seconds)

inputs

required [string]

A list of upstream source or transform IDs. Wildcards (*) are supported.

See configuration for more info.

Array string literal
Examples 
[
  "my-source-or-transform-id",
  "prefix-*"
]

quantiles

optional [float]
Quantiles to use for aggregating distribution metrics into a summary.
Array float
Examples 
[
  0.5,
  0.75,
  0.9,
  0.95,
  0.99
]
default: [0.5 0.75 0.9 0.95 0.99]

tls

optional object
Configures the TLS options for incoming connections.

tls.ca_file

optional string literal
Absolute path to an additional CA certificate file, in DER or PEM format (X.509), or an in-line CA certificate in PEM format.
Examples 
"/path/to/certificate_authority.crt"

tls.crt_file

optional string literal
Absolute path to a certificate file used to identify this server, in DER or PEM format (X.509) or PKCS#12, or an in-line certificate in PEM format. If this is set, and is not a PKCS#12 archive, key_file must also be set. This is required if enabled is set to true.
Examples 
"/path/to/host_certificate.crt"

tls.enabled

optional bool
Require TLS for incoming connections. If this is set, an identity certificate is also required.
default: false

tls.key_file

optional string literal
Absolute path to a private key file used to identify this server, in DER or PEM format (PKCS#8), or an in-line private key in PEM format.
Examples 
"/path/to/host_certificate.key"

tls.key_pass

optional string literal
Pass phrase used to unlock the encrypted key file. This has no effect unless key_file is set.
Examples 
"${KEY_PASS_ENV_VAR}"
"PassWord1"

tls.verify_certificate

optional bool
If true, Vector will require a TLS certificate from the connecting host and terminate the connection if the certificate is not valid. If false (the default), Vector will not request a certificate from the client.
default: false

Telemetry

Metrics

link

buffer_byte_size

gauge
The number of bytes current in the buffer.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

buffer_discarded_events_total

counter
The number of events dropped by this non-blocking buffer.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

buffer_events

gauge
The number of events currently in the buffer.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

buffer_received_event_bytes_total

counter
The number of bytes received by this buffer.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

buffer_received_events_total

counter
The number of events received by this buffer.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

buffer_sent_event_bytes_total

counter
The number of bytes sent by this buffer.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

buffer_sent_events_total

counter
The number of events sent by this buffer.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

component_received_event_bytes_total

counter
The number of event bytes accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_events_count

histogram
A histogram of Vector the number of events passed in each internal batch in Vector’s internal topology. Note that this is separate than sink-level batching. It is mostly useful for low level debugging performance issues in Vector due to small internal batches.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

component_received_events_total

counter
The number of events accepted by this component either from tagged origins like file and uri, or cumulatively from other origins.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

events_in_total

counter
The number of events accepted by this component either from tagged origins like file and uri, or cumulatively from other origins. This metric is deprecated and will be removed in a future version. Use component_received_events_total instead.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
container_name optional
The name of the container from which the data originated.
file optional
The file from which the data originated.
host optional
The hostname of the system Vector is running on.
mode optional
The connection mode used by the component.
peer_addr optional
The IP from which the data originated.
peer_path optional
The pathname from which the data originated.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the data originated.
uri optional
The sanitized URI from which the data originated.

utilization

gauge
A ratio from 0 to 1 of the load on a component. A value of 0 would indicate a completely idle component that is simply waiting for input. A value of 1 would indicate a that is never idle. This value is updated every 5 seconds.
component_id required
The Vector component ID.
component_kind required
The Vector component kind.
component_name required
Deprecated, use component_id instead. The value is the same as component_id.
component_type required
The Vector component type.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.

Examples

Counter

Given this event...
{
  "metric": {
    "counter": {
      "value": 1.5
    },
    "kind": "incremental",
    "name": "logins",
    "tags": {
      "host": "my-host.local"
    }
  }
}
...and this configuration...
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]
default_namespace = "service"

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id
    default_namespace: service

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ],
      "default_namespace": "service"
    }
  }
}
...this Vector event is produced:
# HELP service_logins logins
# TYPE service_logins counter
service_logins{host="my-host.local"} 1.5

Gauge

Given this event...
{
  "metric": {
    "gauge": {
      "value": 1.5
    },
    "kind": "absolute",
    "name": "memory_rss",
    "namespace": "app",
    "tags": {
      "host": "my-host.local"
    }
  }
}
...and this configuration...
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ]
    }
  }
}
...this Vector event is produced:
# HELP app_memory_rss memory_rss
# TYPE app_memory_rss gauge
app_memory_rss{host="my-host.local"} 1.5

Histogram

Given this event...
{
  "metric": {
    "histogram": {
      "buckets": [
        {
          "count": 0,
          "upper_limit": 0.005
        },
        {
          "count": 1,
          "upper_limit": 0.01
        },
        {
          "count": 0,
          "upper_limit": 0.025
        },
        {
          "count": 1,
          "upper_limit": 0.05
        },
        {
          "count": 0,
          "upper_limit": 0.1
        },
        {
          "count": 0,
          "upper_limit": 0.25
        },
        {
          "count": 0,
          "upper_limit": 0.5
        },
        {
          "count": 0,
          "upper_limit": 1
        },
        {
          "count": 0,
          "upper_limit": 2.5
        },
        {
          "count": 0,
          "upper_limit": 5
        },
        {
          "count": 0,
          "upper_limit": 10
        }
      ],
      "count": 2,
      "sum": 0.789
    },
    "kind": "absolute",
    "name": "response_time_s",
    "tags": {}
  }
}
...and this configuration...
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ]
    }
  }
}
...this Vector event is produced:
# HELP response_time_s response_time_s
# TYPE response_time_s histogram
response_time_s_bucket{le="0.005"} 0
response_time_s_bucket{le="0.01"} 1
response_time_s_bucket{le="0.025"} 0
response_time_s_bucket{le="0.05"} 1
response_time_s_bucket{le="0.1"} 0
response_time_s_bucket{le="0.25"} 0
response_time_s_bucket{le="0.5"} 0
response_time_s_bucket{le="1.0"} 0
response_time_s_bucket{le="2.5"} 0
response_time_s_bucket{le="5.0"} 0
response_time_s_bucket{le="10.0"} 0
response_time_s_bucket{le="+Inf"} 0
response_time_s_sum 0.789
response_time_s_count 2

Distribution to histogram

Given this event...
{
  "metric": {
    "distribution": {
      "samples": [
        {
          "rate": 4,
          "value": 0
        },
        {
          "rate": 2,
          "value": 1
        },
        {
          "rate": 1,
          "value": 4
        }
      ],
      "statistic": "histogram"
    },
    "kind": "incremental",
    "name": "request_retries",
    "tags": {
      "host": "my-host.local"
    }
  }
}
...and this configuration...
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]
buckets = [ 0, 1, 3 ]

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id
    buckets:
      - 0
      - 1
      - 3

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ],
      "buckets": [
        0,
        1,
        3
      ]
    }
  }
}
...this Vector event is produced:
# HELP request_retries request_retries
# TYPE request_retries histogram
request_retries_bucket{host="my-host.local",le="0"} 4
request_retries_bucket{host="my-host.local",le="1"} 6
request_retries_bucket{host="my-host.local",le="3"} 6
request_retries_bucket{host="my-host.local",le="+Inf"} 7
request_retries_sum{host="my-host.local"} 6
request_retries_count{host="my-host.local"} 7

Distribution to summary

Given this event...
{
  "metric": {
    "distribution": {
      "samples": [
        {
          "rate": 3,
          "value": 0
        },
        {
          "rate": 2,
          "value": 1
        },
        {
          "rate": 1,
          "value": 4
        }
      ],
      "statistic": "summary"
    },
    "kind": "incremental",
    "name": "request_retries",
    "tags": {}
  }
}
...and this configuration...
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]
quantiles = [ 0.5, 0.75, 0.95 ]

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id
    quantiles:
      - 0.5
      - 0.75
      - 0.95

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ],
      "quantiles": [
        0.5,
        0.75,
        0.95
      ]
    }
  }
}
...this Vector event is produced:
# HELP request_retries request_retries
# TYPE request_retries summary
request_retries{quantile="0.5"} 0
request_retries{quantile="0.75"} 1
request_retries{quantile="0.95"} 4
request_retries_sum 6
request_retries_count 6
request_retries_min 0
request_retries_max 4
request_retries_avg 1

Summary

Given this event...
{
  "metric": {
    "kind": "absolute",
    "name": "requests",
    "summary": {
      "count": 6,
      "quantiles": [
        {
          "upper_limit": 0.01,
          "value": 1.5
        },
        {
          "upper_limit": 0.5,
          "value": 2
        },
        {
          "upper_limit": 0.99,
          "value": 3
        }
      ],
      "sum": 12
    },
    "tags": {
      "host": "my-host.local"
    }
  }
}
...and this configuration...
[sinks.my_sink_id]
type = "prometheus_exporter"
inputs = [ "my-source-or-transform-id" ]

---
sinks:
  my_sink_id:
    type: prometheus_exporter
    inputs:
      - my-source-or-transform-id

{
  "sinks": {
    "my_sink_id": {
      "type": "prometheus_exporter",
      "inputs": [
        "my-source-or-transform-id"
      ]
    }
  }
}
...this Vector event is produced:
# HELP requests requests
# TYPE requests summary
requests{host="my-host.local",quantile="0.01"} 1.5
requests{host="my-host.local",quantile="0.5"} 2
requests{host="my-host.local",quantile="0.99"} 3
requests_sum{host="my-host.local"} 12
requests_count{host="my-host.local"} 6

How it works

Buffers

This component buffers events as shown in the diagram above. This helps to smooth out data processing if the downstream service applies backpressure. Buffers are controlled via the buffer.* options.

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.
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