Sample

Sample events from an event stream based on supplied criteria and at a configurable rate

status: beta egress: stream state: stateless
Samples events at a configurable rate.

Configuration

Example configurations

{
  "transforms": {
    "my_transform_id": {
      "type": "sample",
      "inputs": [
        "my-source-or-transform-id"
      ],
      "exclude": null,
      "rate": 10
    }
  }
}
[transforms.my_transform_id]
type = "sample"
inputs = [ "my-source-or-transform-id" ]
rate = 10
---
transforms:
  my_transform_id:
    type: sample
    inputs:
      - my-source-or-transform-id
    exclude: null
    rate: 10
{
  "transforms": {
    "my_transform_id": {
      "type": "sample",
      "inputs": [
        "my-source-or-transform-id"
      ],
      "key_field": "message",
      "exclude": null,
      "rate": 10
    }
  }
}
[transforms.my_transform_id]
type = "sample"
inputs = [ "my-source-or-transform-id" ]
key_field = "message"
rate = 10
---
transforms:
  my_transform_id:
    type: sample
    inputs:
      - my-source-or-transform-id
    key_field: message
    exclude: null
    rate: 10

exclude

common optional condition
The set of logical conditions to exclude events from sampling.

exclude.source

The text of the condition. The syntax of the condition depends on the value of type.

exclude.type

The type of condition to supply. See Available syntaxes below for a list of available types for this transform.

Available syntaxes

SyntaxDescriptionExample
vrlA Vector Remap Language (VRL) Boolean expression..status_code != 200 && !includes(["info", "debug"], .severity)
datadog_searchA Datadog Search query string.*stack

Shorthand for VRL

If you opt for the vrl syntax for this condition, you can set the condition as a string via the condition parameter, without needing to specify both a source and a type. The table below shows some examples:

Config formatExample
TOMLcondition = ".status == 200"
YAMLcondition: .status == 200
JSON"condition": ".status == 200"

Condition config examples

Standard VRL

exclude = { type = "vrl", source = ".status == 500" }
exclude:
  type: "vrl"
  source: ".status == 500"
"exclude": {
  "type": "vrl",
  "source": ".status == 500"
}
exclude = { type = "datadog_search", source = "*stack" }
exclude:
  type: "datadog_search"
  source: "*stack"
"exclude": {
  "type": "datadog_search",
  "source": "*stack"
}

VRL shorthand

exclude = ".status == 500"
exclude: ".status == 500"
"exclude": ".status == 500"

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-*"
]

key_field

optional string literal

The name of the log field whose value will be hashed to determine if the event should be passed.

Consistently samples the same events. Actual rate of sampling may differ from the configured one if values in the field are not uniformly distributed. If left unspecified, or if the event doesn’t have key_field, events will be count rated.

Examples
"message"

rate

required uint
The rate at which events will be forwarded, expressed as 1/N. For example, rate = 10 means 1 out of every 10 events will be forwarded and the rest will be dropped.
Examples
10

Outputs

<component_id>

Default output stream of the component. Use this component’s ID as an input to downstream transforms and sinks.

Telemetry

Metrics

link

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.

component_sent_event_bytes_total

counter
The total number of event bytes emitted by this component.
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.
output optional
The specific output of the component.
pid optional
The process ID of the Vector instance.

component_sent_events_total

counter
The total number of events emitted by this component.
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.
output optional
The specific output of the component.
pid optional
The process ID of the Vector instance.

events_discarded_total

counter
The total number of events discarded by this component.
host optional
The hostname of the system Vector is running on.
pid optional
The process ID of the Vector instance.
reason required
The type of the error

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.

events_out_total

counter
The total number of events emitted by this component. This metric is deprecated and will be removed in a future version. Use component_sent_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.
host optional
The hostname of the system Vector is running on.
output optional
The specific output of the component.
pid optional
The process ID of the Vector instance.

processed_bytes_total

counter
The number of bytes processed by the component.
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 bytes originate.
file optional
The file from which the bytes originate.
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 bytes originate.
peer_path optional
The pathname from which the bytes originate.
pid optional
The process ID of the Vector instance.
pod_name optional
The name of the pod from which the bytes originate.
uri optional
The sanitized URI from which the bytes originate.

processed_events_total

counter
The total number of events processed by this component. This metric is deprecated in place of using component_received_events_total and component_sent_events_total metrics.
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.

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.

How it works

State

This component is stateless, meaning its behavior is consistent across each input.