Configuring the Metric Registrar

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This topic describes the Metric Registrar for Pivotal Application Service (PAS). It also includes information about enabling and configuring the Metric Registrar.

Overview

The Metric Registrar allows app developers to export custom app metrics in a format that Loggregator can consume. App developers can then use the custom metrics to monitor apps with PCF Metrics and configure autoscaling rules with PCF Autoscaler.

App developers can export custom metrics to Loggregator by configuring their apps in one of the following ways:

  • Metrics Endpoint: Publish and register a Prometheus Exposition metrics endpoint to an app. The Metric Registrar then polls this endpoint every 35 seconds and convert the metrics found in the response to Loggregator metrics.

  • Structured Log: Modify your app to emit metrics using a specific JSON or DogStatsD format. The Metric Registrar then converts all matching log messages into Loggregator metrics or events.

For more information about installing the Metric Registrar Plugin and registering your app, see Emitting Custom App Metrics to the Metric Registrar.

For more information about the components and products mentioned, see:

Architecture

The following diagram illustrates how the Metric Registrar sends your custom app metrics to Loggregator. The components of the Metric Registrar are as follows:

  • The cf CLI plugin

  • The metric_registrar_endpoint_worker and metric_registrar_log_worker jobs running on the Doppler VM of the PAS deployment

  • The metric_registrar_orchestrator and metric_registrar_smoke_test jobs running on the Clock Global VM of the PAS deployment

Metric Registrar Architecture Diagram

Click the image for a larger representation.

Configure the Metric Registrar

Note: The Metric Registrar is bundled with PAS, and you configure it within the PAS tile. You do not install and configure Metric Registrar as a separate product tile.

In the Metric Registrar pane, you configure the Metric Registrar. Metric Registrar allows the conversion of structured logs into metrics. It also scrapes metrics endpoints and forwards the metrics to Loggregator. If enabled, Pivotal recommends also enabling the Metric Registrar Smoke Test errand.

Disable the Metric Registrar

The Metric Registrar is enabled by default.

To disable the Metric Registrar:

  1. Select Metric Registrar.

  2. Clear the Enable Metric Registrar checkbox.

Edit Default Scraping Interval

The scraping interval defines how often the Metric Registrar polls custom metric endpoints. The default is 35 seconds.

To edit the Metric Registrar scraping interval:

  1. Select Metric Registrar.

  2. Edit the Endpoint Scraping Interval field.

Add Blacklisted Tags

To prevent the Metric Registrar from consuming the value of a metric or event tag, you can add the tag to the Blacklisted Tags field. For example, if you tag your metrics with a customer_id, you may want to add customer_id to the list of blacklisted tags.

By default, the following tags are blacklisted to prevent interference with other products like PCF Metrics that use and rely on such tags.

  • deployment
  • job
  • index
  • id

To prevent the Metric Registrar from consuming the value of a metric or event tag:

  1. Select Metric Registrar.

  2. Add the desired tags to the Blacklisted Tags field in a comma-separated list.