Module io.helidon.metrics
Package io.helidon.metrics

Class MetricsSupport

java.lang.Object
io.helidon.servicecommon.rest.HelidonRestServiceSupport
io.helidon.metrics.MetricsSupport
All Implemented Interfaces:
MetricsSupport, RestServiceSupport, Service
public final class MetricsSupport extends HelidonRestServiceSupport implements MetricsSupport
Support for metrics for Helidon Web Server.

By defaults creates the /metrics endpoint with three sub-paths: application, vendor and base.

To register with web server: 


 Routing.builder()
        .register(MetricsSupport.create())

This class supports finer grained configuration using Helidon Config: create(Config). The following configuration parameters can be used:

Configuration parameters
keydefault valuedescription
helidon.metrics.context/metricsContext root under which the rest endpoints are available
helidon.metrics.base.${metricName}.enabledtrueCan control which base metrics are exposed, set to false to disable a base metric

The application metrics registry is then available as follows: 


  req.context().get(MetricRegistry.class).ifPresent(reg -> reg.counter("myCounter").inc());

  • Constructor Details

    • MetricsSupport

      protected MetricsSupport(MetricsSupport.Builder builder)
      Creates a new MetricsSupport instance from the provided builder.
      Parameters:
      builder - the builder for preparing the new instance

    • MetricsSupport

      protected MetricsSupport(MetricsSettings metricsSettings, RestServiceSettings restServiceSettings)
      Creates a new MetricsSupport instance from the provides settings.
      Parameters:
      metricsSettings - the metrics settings to use in preparing the MetricsSupport instance
      restServiceSettings - rest services settings to use in preparing the MetricsSupport instance

  • Method Details

    • create

      public static MetricsSupport create()
      Create an instance to be registered with Web Server with all defaults.
      Returns:
      a new instance built with default values (for context, base metrics enabled)

    • create

      public static MetricsSupport create(MetricsSettings metricsSettings, RestServiceSettings restServiceSettings)
      Create an instance to be registered with Web Server with the specific metrics settings.
      Parameters:
      metricsSettings - metrics settings to use for initializing metrics
      restServiceSettings - REST service settings for managing the endpoint
      Returns:
      a new instance built with the specified metrics settings

    • create

      public static MetricsSupport create(Config config)
      Create an instance to be registered with Web Server maybe overriding default values with configured values.
      Parameters:
      config - Config instance to use to (maybe) override configuration of this component. See class javadoc for supported configuration keys.
      Returns:
      a new instance configured withe config provided

    • builder

      @Deprecated(since="2.5.2", forRemoval=true) public static MetricsSupport.Builder builder()
      Deprecated, for removal: This API element is subject to removal in a future version.
      Use MetricsSupport.builder() instead.
      Create a new builder to construct an instance.
      Returns:
      A new builder instance

    • toPrometheusData

      public static String toPrometheusData(MetricID metricID, Metric metric, boolean withHelpType)
      Formats a metric in Prometheus format.
      Parameters:
      metricID - the MetricID for the metric to be formatted
      metric - the Metric containing the data to be formatted
      withHelpType - flag controlling serialization of HELP and TYPE
      Returns:
      metric info in Prometheus format

    • toPrometheusData

      public static String toPrometheusData(String name, Metric metric, boolean withHelpType)
      Formats a metric in Prometheus format.
      Parameters:
      name - the name of the metric
      metric - the Metric containing the data to be formatted
      withHelpType - flag controlling serialization of HELP and TYPE
      Returns:
      metric info in Prometheus format

    • configureVendorMetrics

      public void configureVendorMetrics(String routingName, Routing.Rules rules)
      Configure vendor metrics on the provided routing. This method is exclusive to update(io.helidon.webserver.Routing.Rules) (e.g. you should not use both, as otherwise you would duplicate the metrics)
      Specified by:
      configureVendorMetrics in interface MetricsSupport
      Parameters:
      routingName - name of the routing (may be null)
      rules - routing builder or routing rules

    • postConfigureEndpoint

      protected void postConfigureEndpoint(Routing.Rules defaultRules, Routing.Rules serviceEndpointRoutingRules)
      Finish configuring metrics endpoint on the provided routing rules. This method just adds the endpoint /metrics (or appropriate one as configured). For simple routings, just register MetricsSupport instance. This method is exclusive to update(io.helidon.webserver.Routing.Rules) (e.g. you should not use both, as otherwise you would register the endpoint twice)
      Specified by:
      postConfigureEndpoint in class HelidonRestServiceSupport
      Parameters:
      defaultRules - routing rules for default routing (also accepts Routing.Builder)
      serviceEndpointRoutingRules - possibly different rules for the metrics endpoint routing

    • prepareMetricsEndpoints

      public void prepareMetricsEndpoints(String endpointContext, Routing.Rules serviceEndpointRoutingRules)
      Description copied from interface: MetricsSupport
      Prepares the family of /metrics endpoints.

      By default, requests to the metrics endpoints trigger a 404 response with an explanatory message that metrics are disabled. Implementations of this interface can provide more informative endpoints.

      Specified by:
      prepareMetricsEndpoints in interface MetricsSupport
      Parameters:
      endpointContext - context (typically /metrics)
      serviceEndpointRoutingRules - routing rules to update with the disabled metrics endpoints

    • update

      public void update(Routing.Rules rules)
      Method invoked by the web server to update routing rules. Register this instance with webserver through Routing.Builder.register(io.helidon.webserver.Service...) rather than calling this method directly. If multiple sockets (and routings) should be supported, you can use the HelidonRestServiceSupport.configureEndpoint(io.helidon.webserver.Routing.Rules, io.helidon.webserver.Routing.Rules), and configureVendorMetrics(String, io.helidon.webserver.Routing.Rules) methods.
      Specified by:
      update in interface MetricsSupport
      Specified by:
      update in interface Service
      Parameters:
      rules - a routing rules to update

    • onShutdown

      protected void onShutdown()
      Description copied from class: HelidonRestServiceSupport
      Logic to run when the service is shut down.
      Overrides:
      onShutdown in class HelidonRestServiceSupport