[CONF] Apache Camel > Metrics Component

[Lauri Kimmel (Confluence)]

Lauri Kimmel created a page: Metrics Component Metrics Component Available as of Camel 2.14 The metrics: component allows you to collect various metrics directly from Camel routes. Supported metric types are counter, histogram, meter and timer. Metrics provides simple way to measure behaviour of your application. Configurable reporting backend is enabling different integration options for collecting and visualizing statistics. Maven users will need to add the following dependency to their pom.xml for this component: <dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-metrics</artifactId> <version>x.x.x</version> <!-- use the same version as your Camel core version --> </dependency> URI format metrics:[ meter | counter | histogram | timer ]:metricname[?options] Metric Registry Camel Metrics Component uses by default MetricRegistry with Slf4jReporter and 60 second reporting interval. Default registry can be replaced with custom one by providing bean with name metricRegistry in Camel registry. For example using Spring Java Configuration. @Configuration public static class MyConfig extends SingleRouteCamelConfiguration { @Bean @Override public RouteBuilder route() { return new RouteBuilder() { @Override public void configure() throws Exception { // define Camel routes here } }; } @Bean(name = MetricsComponent.METRIC_REGISTRY_NAME) public MetricRegistry getMetricRegistry() { MetricRegistry registry = ...; return registry; } } Icon MetricRegistry uses internal thread(s) for reporting. There is no public API in version 3.0.1 for users to clean up on exit. Thus using Camel Metrics Component leads to Java classloader leak and my cause OutOfMemoryErrors in some cases. Usage Each metric has type and name. Supported types are counter, histogram, meter and timer. Metric name is simple string. If metric type is not provided then type meter is used by default. Headers Metric name defined in URI can be overridden by using header with name CamelMetricsName. For example from("direct:in") .setHeader(MetricsConstants.HEADER_METRIC_NAME, constant("new.name")) .to("metrics:counter:name.not.used") .to("direct:out"); will update counter with name new.name instead of name.not.used. All Metrics specific headers are removed from the message once Metrics endpoint finishes processing of exchange. While processing exchange Metrics endpoint will catch all exceptions and write log entry using level warn. Metrics type counter metrics:counter:metricname[?options] Options Name Default Description increment  - Long value to add to the counter decrement - Long value to subtract from the counter If neither increment or decrement is defined then counter value will be incremented by one. If increment and decrement are both defined only increment operation is called.  // update counter simple.counter by 7 from("direct:in") .to("metric:counter:simple.counter?increment=7") .to("direct:out"); // increment counter simple.counter by 1 from("direct:in") .to("metric:counter:simple.counter") .to("direct:out"); // decrement counter simple.counter by 3 from("direct:in") .to("metric:counter:simple.counter?decrement=3") .to("direct:out"); Headers Message headers can be used to override increment and decrement values specified in Metrics component URI. Name Description Expected type CamelMetricsCounterIncrement  Override increment value in URI Long CamelMetricsCounterDecrement  Override decrement value in URI Long // update counter simple.counter by 417 from("direct:in") .setHeader(MetricsConstants.HEADER_COUNTER_INCREMENT, constant(417L)) .to("metric:counter:simple.counter?increment=7") .to("direct:out"); // updates counter using simple language to evaluate body.length from("direct:in") .setHeader(MetricsConstants.HEADER_COUNTER_INCREMENT, simple("${body.length}")) .to("metrics:counter:body.length") .to("mock:out"); Metric type histogram metrics:histogram:metricname[?options] Options Name Default Description value - Value to use in histogram If no value is not set nothing is added to histogram and warning is logged. // adds value 9923 to simple.histogram from("direct:in") .to("metric:histogram:simple.histogram?value=9923") .to("direct:out"); // nothing is added to simple.histogram; warning is logged from("direct:in") .to("metric:histogram:simple.histogram") .to("direct:out"); Headers Message header can be used to override value specified in Metrics component URI. Name Description Expected type CamelMetricsHistogramValue Override histogram value in URI Long // adds value 992 to simple.histogram from("direct:in") .setHeader(MetricsConstants.HEADER_HISTOGRAM_VALUE, constant(992L)) .to("metric:histogram:simple.histogram?value=700") .to("direct:out") Metric type meter metrics:meter:metricname[?options] Options Name Default Description mark  - Long value to use as mark If mark is not set then meter.mark() is called without argument. // marks simple.meter without value from("direct:in") .to("metric:simple.meter") .to("direct:out"); // marks simple.meter with value 81 from("direct:in") .to("metric:meter:simple.meter?mark=81") .to("direct:out"); Headers Message header can be used to override mark value specified in Metrics component URI. Name Description Expected type CamelMetricsMeterMark Override mark value in URI Long // updates meter simple.meter with value 345 from("direct:in") .setHeader(MetricsConstants.HEADER_METER_MARK, constant(345L)) .to("metric:meter:simple.meter?mark=123") .to("direct:out"); Metrics type timer metrics:timer:metricname[?options] Options Name Default Description action - start or stop If no action or invalid value is provided then warning is logged without any timer update. If action start is called on already running timer or stop is called on not running timer then nothing is updated and warning is logged. // measure time taken by route "calculate" from("direct:in") .to("metrics:timer:simple.timer?action="" .to("direct:calculate") .to("metrics:timer:simple.timer?action=""> TimerContext objects are stored as Exchange properties between different Metrics component calls. Headers Message header can be used to override action value specified in Metrics component URI. Name Description Expected type CamelMetricsTimerAction Override timer action in URI org.apache.camel.component.metrics.timer.TimerEndpoint.TimerAction // sets timer action using header from("direct:in") .setHeader(MetricsConstants.HEADER_TIMER_ACTION, TimerAction.start) .to("metric:timer:simple.timer") .to("direct:out"); View Online · Like Stop watching space · Manage Notifications This message was sent by Atlassian Confluence 5.0.3, Team Collaboration Software