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Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.

Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Open source

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

river
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:

NameTypeDescriptionDefaultRequired
check_intervaldurationHow often to check memory usage.yes
limitstringMaximum amount of memory targeted to be allocated by the process heap."0MiB"no
spike_limitstringMaximum spike expected between the measurements of memory usage.20% of limitno
limit_percentageintMaximum amount of total available memory targeted to be allocated by the process heap.0no
spike_limit_percentageintMaximum spike expected between the measurements of memory usage.0no

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:

HierarchyBlockDescriptionRequired
outputoutputConfigures where to send received telemetry data.yes

output block

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

The following arguments are supported:

NameTypeDescriptionDefaultRequired
metricslist(otelcol.Consumer)List of consumers to send metrics to.[]no
logslist(otelcol.Consumer)List of consumers to send logs to.[]no
traceslist(otelcol.Consumer)List of consumers to send traces to.[]no

The output block must be specified, but all of its arguments are optional. By default, telemetry data is dropped. To send telemetry data to other components, configure the metrics, logs, and traces arguments accordingly.

Exported fields

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

NameTypeDescription
inputotelcol.ConsumerA value that other components can use to send telemetry data to.

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.