Sample Transform

The Vector sample transform samples events at a configurable rate.

Configuration

[transforms.my_transform_id]
type = "sample" # required
inputs = ["my-source-or-transform-id", "prefix-*"] # required
exclude = '.status_code != 200 && !includes(["info", "debug"], .severity)' # optional, no default
rate = 10 # required
  • commonoptionalstring

    exclude

    The set of logical conditions to exclude events from sampling.

    This field accepts a Vector Remap Language (VRL) comparison expression, it must return a boolean.

    Please refer to the Vector Remap Language reference for a list of expressions, functions, and examples.

    • Syntax: remap_boolean_expression
  • optionalstring

    key_field

    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.

    • Syntax: literal
  • commonrequireduint

    rate

    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.

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_discarded_total

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

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

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

  • 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

    processed_events_total

    The total number of events processed 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.

    • file - The file that produced the error

    • 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.

  • counter

    processed_bytes_total

    The total number of bytes processed by the 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.

How It Works

State

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