Package org.apache.solr.metrics

Class SolrMetricsContext

java.lang.Object

org.apache.solr.metrics.SolrMetricsContext

public class SolrMetricsContext
extends Object

This class represents a metrics context that ties together components with the same life-cycle and provides convenient access to the metric registry.

Additionally it's used for registering and reporting metrics specific to the components that use the same instance of context.

Constructor Summary

Constructors

Constructor	Description
SolrMetricsContext(SolrMetricManager metricManager, String registryName, String tag)

Method Summary

Modifier and Type	Method	Description
com.codahale.metrics.Counter	counter(String metricName, String... metricPath)	Convenience method for SolrMetricManager.counter(SolrMetricsContext, String, String, String...).
void	gauge(com.codahale.metrics.Gauge<?> gauge, boolean force, String metricName, String... metricPath)	Convenience method for SolrMetricManager.registerGauge(SolrMetricsContext, String, Gauge, String, SolrMetricManager.ResolutionStrategy, String, String...).
SolrMetricsContext	getChildContext(Object child)	Get a context with the same registry name but a tag that represents a parent-child relationship.
SolrMetricManager	getMetricManager()	Return the instance of SolrMetricManager used in this context.
Set<String>	getMetricNames()	Return a modifiable set of metric names that this component registers.
com.codahale.metrics.MetricRegistry	getMetricRegistry()	Get the MetricRegistry instance that is used for registering metrics in this context.
Map<String,Object>	getMetricsSnapshot()	Return a snapshot of metric values that this component reports.
String	getRegistryName()	Return metric registry name used in this context.
String	getTag()	Metrics tag that represents objects with the same life-cycle.
com.codahale.metrics.Histogram	histogram(String metricName, String... metricPath)	Convenience method for SolrMetricManager.histogram(SolrMetricsContext, String, String, String...).
com.codahale.metrics.Meter	meter(String metricName, String... metricPath)	Convenience method for SolrMetricManager.meter(SolrMetricsContext, String, String, String...).
Object	notANumber()	See SolrMetricManager.notANumber().
Object	nullNumber()	See SolrMetricManager.nullNumber().
Object	nullObject()	See SolrMetricManager.nullObject().
Object	nullString()	See SolrMetricManager.nullString().
void	registerMetricName(String name)	Register a metric name that this component reports.
com.codahale.metrics.Timer	timer(String metricName, String... metricPath)	Convenience method for SolrMetricManager.meter(SolrMetricsContext, String, String, String...).
void	unregister()	Unregister all Gauge metrics that use this context's tag.

Methods inherited from class java.lang.Object

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

Constructor Detail

SolrMetricsContext

public SolrMetricsContext(SolrMetricManager metricManager,
                          String registryName,
                          String tag)

Method Detail

nullNumber

public Object nullNumber()

See SolrMetricManager.nullNumber().

notANumber

public Object notANumber()

See SolrMetricManager.notANumber().

nullString

public Object nullString()

See SolrMetricManager.nullString().

nullObject

public Object nullObject()

See SolrMetricManager.nullObject().

getTag

public String getTag()

Metrics tag that represents objects with the same life-cycle.

getRegistryName

public String getRegistryName()

Return metric registry name used in this context.

getMetricManager

public SolrMetricManager getMetricManager()

Return the instance of SolrMetricManager used in this context.

getMetricNames

public Set<String> getMetricNames()

Return a modifiable set of metric names that this component registers.

unregister

public void unregister()

Unregister all Gauge metrics that use this context's tag.

NOTE: This method MUST be called at the end of a life-cycle (typically in close() ) of components that register gauge metrics with references to the current object's instance. Failure to do so may result in hard-to-debug memory leaks.

getChildContext

public SolrMetricsContext getChildContext(Object child)

Get a context with the same registry name but a tag that represents a parent-child relationship. Since it's a different tag than the parent's context it is assumed that the life-cycle of the parent and child are different.

Parameters:

child - child object that produces metrics with a different life-cycle than the parent.

registerMetricName

public void registerMetricName(String name)

Register a metric name that this component reports. This method is called by various metric registration methods in SolrMetricManager in order to capture what metric names are reported from this component (which in turn is called from SolrMetricProducer.initializeMetrics(SolrMetricsContext, String)).

getMetricsSnapshot

public Map<String,Object> getMetricsSnapshot()

Return a snapshot of metric values that this component reports.

meter

public com.codahale.metrics.Meter meter(String metricName,
                                        String... metricPath)

Convenience method for SolrMetricManager.meter(SolrMetricsContext, String, String, String...).

counter

public com.codahale.metrics.Counter counter(String metricName,
                                            String... metricPath)

Convenience method for SolrMetricManager.counter(SolrMetricsContext, String, String, String...).

gauge

public void gauge(com.codahale.metrics.Gauge<?> gauge,
                  boolean force,
                  String metricName,
                  String... metricPath)

Convenience method for SolrMetricManager.registerGauge(SolrMetricsContext, String, Gauge, String, SolrMetricManager.ResolutionStrategy, String, String...).

timer

public com.codahale.metrics.Timer timer(String metricName,
                                        String... metricPath)

Convenience method for SolrMetricManager.meter(SolrMetricsContext, String, String, String...).

histogram

public com.codahale.metrics.Histogram histogram(String metricName,
                                                String... metricPath)

Convenience method for SolrMetricManager.histogram(SolrMetricsContext, String, String, String...).

getMetricRegistry

public com.codahale.metrics.MetricRegistry getMetricRegistry()

Get the MetricRegistry instance that is used for registering metrics in this context.