org.springframework.boot.actuate.metrics.aggregate

Class AggregateMetricReader

java.lang.Object

org.springframework.boot.actuate.metrics.aggregate.AggregateMetricReader

All Implemented Interfaces:

MetricReader

public class AggregateMetricReader
extends Object
implements MetricReader

A metric reader that aggregates values from a source reader, normally one that has been collecting data from many sources in the same form (like a scaled-out application). The source has metrics with names in the form *.*.counter.** and *.*.[anything].**, and the result has metric names in the form aggregate.count.** and aggregate.[anything].**. Counters are summed and anything else (i.e. gauges) are aggregated by choosing the most recent value.

Since:

1.3.0

Author:

Dave Syer

Constructor Summary

Constructors

Constructor and Description
AggregateMetricReader(MetricReader source)

Method Summary

Modifier and Type	Method and Description
long	count() The number of metrics known to this reader.
Iterable<Metric<?>>	findAll() Find all the metrics known to this reader.
Metric<?>	findOne(String metricName) Find an instance of the metric with the given name (usually the latest recorded value).
void	setKeyPattern(String keyPattern) Pattern that tells the aggregator what to do with the keys from the source repository.
void	setPrefix(String prefix) Prefix to apply to all output metrics.

Methods inherited from class java.lang.Object

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

Constructor Detail

AggregateMetricReader

public AggregateMetricReader(MetricReader source)

Method Detail

setKeyPattern

public void setKeyPattern(String keyPattern)

Pattern that tells the aggregator what to do with the keys from the source repository. The keys in the source repository are assumed to be period separated, and the pattern is in the same format, e.g. "d.d.k.d". The pattern segments are matched against the source keys and a rule is applied:

• "d" means "discard" this key segment (useful for global prefixes like system identifiers, or aggregate keys a.k.a. physical identifiers)
• "k" means "keep" it with no change (useful for logical identifiers like app names)

Default is "d.d" (we assume there is a global prefix of length 2).

Parameters:

keyPattern - the keyPattern to set

setPrefix

public void setPrefix(String prefix)

Prefix to apply to all output metrics. A period will be appended if not present in the provided value.

Parameters:

prefix - the prefix to use (default "aggregator.")

findOne

public Metric<?> findOne(String metricName)

Description copied from interface: MetricReader

Find an instance of the metric with the given name (usually the latest recorded value).

Specified by:

findOne in interface MetricReader

Parameters:

metricName - the name of the metric to find

Returns:

a metric value or null if there are none with that name

findAll

public Iterable<Metric<?>> findAll()

Description copied from interface: MetricReader

Find all the metrics known to this reader.

Specified by:

findAll in interface MetricReader

Returns:

all instances of metrics known to this reader

count

public long count()

Description copied from interface: MetricReader

The number of metrics known to this reader.

Specified by:

count in interface MetricReader

Returns:

the number of metrics