Documentation Grafana Cloud Instrument and send data Grafana Alloy Reference Components otelcol otelcol.processor.memory_limiter

otelcol.processor.memory_limiter

otelcol.processor.memory_limiter is used to prevent out of memory situations on a telemetry pipeline by performing periodic checks of memory usage. If usage exceeds the defined limits, data is dropped and garbage collections are triggered to reduce it.

The memory_limiter component uses both soft and hard limits, where the hard limit is always equal or larger than the soft limit. When memory usage goes above the soft limit, the processor component drops data and returns errors to the preceding components in the pipeline. When usage exceeds the hard limit, the processor forces a garbage collection in order to try and free memory. When usage is below the soft limit, no data is dropped and no forced garbage collection is performed.

NOTE: otelcol.processor.memory_limiter is a wrapper over the upstream OpenTelemetry Collector memorylimiter processor. Bug reports or feature requests will be redirected to the upstream repository, if necessary.

Multiple otelcol.processor.memory_limiter components can be specified by giving them different labels.

Usage

alloy Copy

otelcol.processor.memory_limiter "LABEL" {
  check_interval = "1s"

  limit = "50MiB" // alternatively, set `limit_percentage` and `spike_limit_percentage`

  output {
    metrics = [...]
    logs    = [...]
    traces  = [...]
  }
}

Arguments

otelcol.processor.memory_limiter supports the following arguments:

The arguments must define either limit or the limit_percentage, spike_limit_percentage pair, but not both.

The configuration options limit and limit_percentage define the hard limits. The soft limits are then calculated as the hard limit minus the spike_limit or spike_limit_percentage values respectively. The recommended value for spike limits is about 20% of the corresponding hard limit.

The recommended check_interval value is 1 second. If the traffic through the component is spiky in nature, it is recommended to either decrease the interval or increase the spike limit to avoid going over the hard limit.

The limit and spike_limit values must be larger than 1 MiB.

Blocks

The following blocks are supported inside the definition of otelcol.processor.memory_limiter:

output block

The output block configures a set of components to forward resulting telemetry data to.

The following arguments are supported:

You must specify the output block, but all its arguments are optional. By default, telemetry data is dropped. Configure the metrics, logs, and traces arguments accordingly to send telemetry data to other components.

debug_metrics block

The debug_metrics block configures the metrics that this component generates to monitor its state.

The following arguments are supported:

disable_high_cardinality_metrics is the Grafana Alloy equivalent to the telemetry.disableHighCardinalityMetrics feature gate in the OpenTelemetry Collector. It removes attributes that could cause high cardinality metrics. For example, attributes with IP addresses and port numbers in metrics about HTTP and gRPC connections are removed.

level is the Alloy equivalent to the telemetry.metrics.level feature gate in the OpenTelemetry Collector. Possible values are "none", "basic", "normal" and "detailed".

Exported fields

The following fields are exported and can be referenced by other components:

input accepts otelcol.Consumer data for any telemetry signal (metrics, logs, or traces).

Component health

otelcol.processor.memory_limiter is only reported as unhealthy if given an invalid configuration.

Debug information

otelcol.processor.memory_limiter does not expose any component-specific debug information.

Compatible components

otelcol.processor.memory_limiter can accept arguments from the following components:

• Components that export OpenTelemetry otelcol.Consumer

otelcol.processor.memory_limiter has exports that can be consumed by the following components:

• Components that consume OpenTelemetry otelcol.Consumer