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

key	default value	description
helidon.metrics.context	/metrics	Context root under which the rest endpoints are available
helidon.metrics.base.${metricName}.enabled	true	Can 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());
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MetricsSupport.Builder	A fluent API builder to build instances of MetricsSupport.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	MetricsSupport(MetricsSettings metricsSettings, RestServiceSettings restServiceSettings)
protected	MetricsSupport(MetricsSupport.Builder builder)

Method Summary

Modifier and Type	Method	Description
static MetricsSupport.Builder	builder()	Deprecated. Use MetricsSupport.builder() instead.
void	configureVendorMetrics(String routingName, Routing.Rules rules)	Configure vendor metrics on the provided routing.
static MetricsSupport	create()	Create an instance to be registered with Web Server with all defaults.
static MetricsSupport	create(Config config)	Create an instance to be registered with Web Server maybe overriding default values with configured values.
static MetricsSupport	create(MetricsSettings metricsSettings, RestServiceSettings restServiceSettings)	Create an instance to be registered with Web Server with the specific metrics settings.
protected void	onShutdown()
protected void	postConfigureEndpoint(Routing.Rules defaultRules, Routing.Rules serviceEndpointRoutingRules)	Finish configuring metrics endpoint on the provided routing rules.
void	prepareMetricsEndpoints(String endpointContext, Routing.Rules serviceEndpointRoutingRules)	Prepares the family of /metrics endpoints.
static String	toPrometheusData(String name, Metric metric, boolean withHelpType)	Formats a metric in Prometheus format.
static String	toPrometheusData(MetricID metricID, Metric metric, boolean withHelpType)	Formats a metric in Prometheus format.
void	update(Routing.Rules rules)	Method invoked by the web server to update routing rules.

Methods inherited from class io.helidon.servicecommon.rest.HelidonRestServiceSupport

configureEndpoint, configureEndpoint, context, logger

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface io.helidon.metrics.serviceapi.MetricsSupport

configureEndpoint

Constructor Detail

MetricsSupport

protected MetricsSupport(MetricsSupport.Builder builder)

MetricsSupport

protected MetricsSupport(MetricsSettings metricsSettings,
                         RestServiceSettings restServiceSettings)

Method Detail

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=false)
public static MetricsSupport.Builder builder()

Deprecated.

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()

Overrides:

onShutdown in class HelidonRestServiceSupport