MicroProfile Metrics

Since Camel 3.0

Only producer is supported

The MircoProfile Metrics component provides the capability to expose metrics from Camel routes.

Maven users need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-microprofile-metrics</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

It is expected that the component is running in a MicroProfile environment that provides an appropriate implementation of MicroProfile Metrics 2.0. E.g SmallRye Metrics.

URI format

microprofile-metrics:[ concurrent gauge | counter | gauge | histogram | meter | timer ]:metricname[?options]

Options

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL as a type safe way of configuring endpoints.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The MicroProfile Metrics component supports 3 options, which are listed below.

Name Description Default Type

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

boolean

metricRegistry (advanced)

Use a custom MetricRegistry.

MetricRegistry

Endpoint Options

The MicroProfile Metrics endpoint is configured using URI syntax:

microprofile-metrics:metricType:metricName

with the following path and query parameters:

Path Parameters (2 parameters)

Name Description Default Type

metricType (producer)

Required Metric type.

Enum values:

  • concurrent gauge

  • counter

  • gauge

  • meter

  • histogram

  • timer

  • simple timer

  • invalid

MetricType

metricName (producer)

Required Metric name.

String

Query Parameters (12 parameters)

Name Description Default Type

action (producer)

Action to use when using the timer type.

String

counterIncrement (producer)

Increment value when using the counter type.

Long

description (producer)

Metric description.

String

displayName (producer)

Metric display name.

String

gaugeDecrement (producer)

Decrement metric value when using concurrent gauge type.

Boolean

gaugeIncrement (producer)

Increment metric value when using the concurrent gauge type.

Boolean

gaugeValue (producer)

Decrement metric value when using concurrent gauge type.

Number

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

boolean

mark (producer)

Mark value to set when using the meter type.

Long

metricUnit (producer)

Metric unit. See org.eclipse.microprofile.metrics.MetricUnits.

String

tags (producer)

Comma delimited list of tags associated with the metric in the format tagName=tagValue.

String

value (producer)

Value to set when using the histogram type.

Long

MetricRegistry Configuration

Configure a MetricRegistry to use either by passing it to the MicroProfileMetricsComponent.

MicroProfileMetricsComponent component = new MicroProfileMetricsComponent();
component.setRegistry(myMetricRegistryImpl);

Or by binding it to the Camel registry using the binding name 'metricRegistry' (See MicroProfileMetricsConstants.METRIC_REGISTRY_NAME).

Counter

microprofile-metrics:counter:name[?options]

Options

Name Default Description

counterIncrement

-

Value to add to the counter

If counterIncrement is not defined then counter value will be incremented by one.

// Increment counter simple.counter by 7
from("direct:in")
    .to("microprofile-metrics:counter:simple.counter?counterIncrement=7")
    .to("direct:out");
// Increment counter simple.counter by 1
from("direct:in")
    .to("microprofile-metrics:counter:simple.counter")
    .to("direct:out");

Headers

Message headers can be used to override the counterIncrement values specified on the microprofile-metrics endpoint URI.

Name Description Expected type

CamelMicroProfileMetricsCounterIncrement

Override increment value from the URI

Long

// Increment counter simple.counter by 417
from("direct:in")
    .setHeader(MicroProfileMetricsConstants.HEADER_COUNTER_INCREMENT, constant(417))
    .to("microprofile-metrics:counter:simple.counter?increment=7")
    .to("direct:out");

Concurrent Gauge

microprofile-metrics:concurrent gauge:name[?options]

Options

Name Default Description

gaugeIncrement

false

Value to add to the counter

gaugeDecrement

false

Value to add to the counter

If neither gaugeIncrement or gaugeDecrement are defined then no action is performed on the gauge.

// Increment concurrent gauge simple.gauge by 1
from("direct:in")
    .to("microprofile-metrics:concurrent gauge:simple.gauge?gaugeIncrement=true")
    .to("direct:out");
// Decrement concurrent gauge simple.gauge by 1
from("direct:in")
    .to("microprofile-metrics:concurrent gauge:simple.gauge?gaugeDecrement=true")
    .to("direct:out");

Headers

Message headers can be used to override the gaugeIncrement and gaugeDecrement values specified on the microprofile-metrics endpoint URI.

Name Description Expected type

CamelMicroProfileMetricsGaugeIncrement

Override gaugeIncrement value from the URI

Boolean

CamelMicroProfileMetricsGaugeDecrement

Override gaugeDecrement value from the URI

Boolean

// Increment concurrent gauge simple.gauge by 1
from("direct:in")
    .setHeader(MicroProfileMetricsConstants.HEADER_GAUGE_INCREMENT, constant(true))
    .to("microprofile-metrics:concurrent gauge:simple.gauge")
    .to("direct:out");

// Decrement concurrent gauge simple.gauge by 1
from("direct:in")
    .setHeader(MicroProfileMetricsConstants.HEADER_GAUGE_DECREMENT, constant(true))
    .to("microprofile-metrics:concurrent gauge:simple.gauge")
    .to("direct:out");

Gauge

microprofile-metrics:gauge:name[?options]

Options

Name Default Description

gaugeValue

false

Value to set the gauge to

If gaugeValue is not defined then no action is performed on the gauge.

// Set gauge simple.gauge value to 10
from("direct:in")
    .to("microprofile-metrics:gauge:simple.gauge?gaugeValue=10")
    .to("direct:out");

Headers

Message headers can be used to override the gaugeValue value specified on the microprofile-metrics endpoint URI.

Name Description Expected type

CamelMicroProfileMetricsGaugeValue

Override gaugeValue value from the URI

Number

// Set gauge simple.gauge value to 10
from("direct:in")
    .setHeader(MicroProfileMetricsConstants.HEADER_GAUGE_VALUE, constant(10))
    .to("microprofile-metrics:gauge:simple.gauge")
    .to("direct:out");

Histogram

microprofile-metrics:histogram:name[?options]

Options

Name Default Description

value

-

Value to set on the histogram

If value is not defined then histogram value will not be changed.

// Set histogram simple.histogram to 7
from("direct:in")
    .to("microprofile-metrics:histogram:simple.histogram?value=7")
    .to("direct:out");

Headers

Message headers can be used to override the value specified on the microprofile-metrics endpoint URI.

Name Description Expected type

CamelMicroProfileMetricsHistogramValue

Override histogram value from the URI

Long

// Set histogram simple.histogram to 417
from("direct:in")
    .setHeader(MicroProfileMetricsConstants.HEADER_HISTOGRAM_VALUE, constant(417))
    .to("microprofile-metrics:histogram:simple.histogram?value=7")
    .to("direct:out");

Meter

microprofile-metrics:meter:name[?options]

Options

Name Default Description

mark

-

Mark value to set on the meter

If mark is not defined then the meter will be marked with the value '1'.

// Mark the meter simple.meter with 7
from("direct:in")
    .to("microprofile-metrics:meter:simple.meter?mark=7")
    .to("direct:out");
// Mark the meter simple.meter with 1
from("direct:in")
    .to("microprofile-metrics:meter:simple.meter")
    .to("direct:out");

Headers

Message headers can be used to override the value specified on the microprofile-metrics endpoint URI.

Name Description Expected type

CamelMicroProfileMetricsMeterMark

Override meter mark value from the URI

Long

// Mark the meter simple.meter with 417
from("direct:in")
    .setHeader(MicroProfileMetricsConstants.HEADER_METER_MARK, constant(417))
    .to("microprofile-metrics:meter:simple.meter?value=7")
    .to("direct:out");

Timer

microprofile-metrics:timer:name[?options]

Options

Name Default Description

action

-

start or stop

If no action is specified or it’s an invalid value, then no timer update occurs.

If the start action is called on an already running timer or stop is called on an unknown timer, then no timer(s) are updated.

// Measure time spent in route `direct:calculate`
from("direct:in")
    .to("microprofile-metrics:timer:simple.timer?action=start")
    .to("direct:calculate")
    .to("microprofile-metrics:timer:simple.timer?action=stop");

Headers

Message headers can be used to override the action specified on the microprofile-metrics endpoint URI.

Name Description Expected type

CamelMicroProfileMetricsTimerAction

Override time action from the URI

org.apache.camel.component.microprofile.metrics.TimerAction

// Mark the meter simple.meter with 417
from("direct:in")
    .setHeader(MicroProfileMetricsConstants.HEADER_TIMER_ACTION, TimerAction.START)
    .to("microprofile-metrics:timer:simple.timer")
    .to("direct:out");

MicroProfileMetricsRoutePolicyFactory

This factory allows to add a RoutePolicy for each route and exposes route utilization statistics using MicroProfile metrics.

Instead of using the MicroProfileMetricsRoutePolicyFactory you can define a MicroProfileMetricsRoutePolicy per route you want to instrument, in case you only want to instrument a few selected routes.

Add the factory to the CamelContext as shown below:

context.addRoutePolicyFactory(new MicroProfileMetricsRoutePolicyFactory());

MicroProfileMetricsMessageHistoryFactory

This factory captures message history performance statistics while routing messages.

Add the factory to the CamelContext as shown below:

context.setMessageHistoryFactory(new MicroProfileMetricsMessageHistoryFactory());

MicroProfileMetricsExchangeEventNotifier

The exchange event notifier times exchanges from creation through to completion.

EventNotifiers can be added to the CamelContext, e.g.:

camelContext.getManagementStrategy().addEventNotifier(new MicroProfileMetricsExchangeEventNotifier())

MicroProfileMetricsRouteEventNotifier

The route event notifier counts added and running routes within the CamelContext.

EventNotifiers can be added to the CamelContext, e.g.:

camelContext.getManagementStrategy().addEventNotifier(new MicroProfileMetricsRouteEventNotifier())

MicroProfileMetricsCamelContextEventNotifier

The Camel Context event notifier adds some basic metrics about the state of the CamelContext.

EventNotifiers can be added to the CamelContext, e.g.:

camelContext.getManagementStrategy().addEventNotifier(new MicroProfileMetricsCamelContextEventNotifier())