incubator

OpenTelemetry Incubator

This artifact contains experimental code related to the trace and metric SDKs.

View File Configuration

Adds support for file based YAML configuration of Metric SDK Views.

For example, suppose /Users/user123/view.yaml has the following content:

- selector:
    instrument_name: my-instrument
    instrument_type: COUNTER
    instrument_unit: ms
    meter_name: my-meter
    meter_version: 1.0.0
    meter_schema_url: http://example.com
  view:
    name: new-instrument-name
    description: new-description
    aggregation: explicit_bucket_histogram
    aggregation_args:
      bucket_boundaries: [1.0, 2.0, 5.0]
    attribute_keys:
      - foo
      - bar

The equivalent view configuration would be:

SdkMeterProvider.builder()
   .registerView(
       InstrumentSelector.builder()
           .setName("my-instrument")
           .setType(InstrumentType.COUNTER)
           .setUnit("ms")
           .setMeterName("my-meter")
           .setMeterVersion("1.0.0")
           .setMeterSchemaUrl("http://example.com")
           .build(),
       View.builder()
           .setName("new-instrument")
           .setDescription("new-description")
           .setAggregation(Aggregation.explicitBucketHistogram(Arrays.asList(1.0, 2.0, 5.0))
           .setAttributesFilter(key -> new HashSet<>(Arrays.asList("foo", "bar")).contains(key))
           .build());

If using autoconfigure with this artifact on your classpath, it will automatically load a list of view config files specified via environment variable or system property:

System property	Environment variable	Purpose
otel.experimental.metrics.view-config	OTEL_EXPERIMENTAL_METRICS_VIEW_CONFIG	List of files containing view configuration YAML [1]

[1] In addition to absolute paths, resources on the classpath packaged with a jar can be loaded. For example, otel.experimental.metrics.view-config=classpath:/my-view.yaml loads the resource /my-view.yaml.

If not using autoconfigure, a file can be used to configure views as follows:

SdkMeterProviderBuilder builder = SdkMeterProvider.builder();
try (FileInputStream fileInputStream = new FileInputStream("/Users/user123/view.yaml")) {
  ViewConfig.registerViews(builder, fileInputStream);
}

The following table describes the set of recognized aggregations:

Aggregation	Arguments
default	-
sum	-
last_value	-
drop	-
explicit_bucket_histogram	bucket_boundaries (optional): List of inclusive upper boundaries for the histogram buckets, in order from lowest to highest.
exponential_bucket_histogram	max_buckets (optional): The maximum number of buckets to use for positive or negative recordings.

Additional notes on usage:

• Many view configurations can live in one file. The YAML is parsed as an array of view configurations.
• At least one selection field is required, but including all is not necessary. Any omitted fields will result in the default from InstrumentSelector being used.
• At least one view field is required, but including all is not required. Any omitted fields will result in the default from View being used.
• Instrument name selection supports the following wildcard characters: * matches 0 or more instances of any character; ? matches exactly one instance of any character. No other advanced selection criteria is supported.