org.apache.hadoop.metrics2.lib

Class DynamicMetricsRegistry

java.lang.Object

org.apache.hadoop.metrics2.lib.DynamicMetricsRegistry

public class DynamicMetricsRegistry
extends Object

An optional metrics registry class for creating and maintaining a collection of MetricsMutables, making writing metrics source easier. NOTE: this is a copy of org.apache.hadoop.metrics2.lib.MetricsRegistry with added one feature: metrics can be removed. When HADOOP-8313 is fixed, usages of this class should be substituted with org.apache.hadoop.metrics2.lib.MetricsRegistry. This implementation also provides handy methods for creating metrics dynamically. Another difference is that metricsMap & tagsMap implementation is substituted with concurrent map, as we allow dynamic metrics additions/removals.

Field Summary

Fields

Modifier and Type	Field and Description
static String	CONTEXT_DESC description for the context tag
static String	CONTEXT_KEY key for the context tag

Constructor Summary

Constructors

Constructor and Description
DynamicMetricsRegistry(String name) Construct the registry with a record name
DynamicMetricsRegistry(String name, org.apache.hadoop.metrics2.lib.MetricMutableFactory factory) Construct the registry with a name and a metric factory

Method Summary

Methods

Modifier and Type	Method and Description
void	clearMetrics()
org.apache.hadoop.metrics2.lib.MetricMutable	get(String name) Get a metric by name
MetricMutableHistogram	getHistogram(String histoName)
org.apache.hadoop.metrics2.lib.MetricMutableCounterLong	getLongCounter(String counterName, long potentialStartingValue) Get a MetricMutableCounterLong from the storage.
org.apache.hadoop.metrics2.lib.MetricMutableGaugeLong	getLongGauge(String gaugeName, long potentialStartingValue) Get a MetricMutableGaugeLong from the storage.
MetricMutableQuantiles	getQuantile(String histoName)
Set<Map.Entry<String,org.apache.hadoop.metrics2.lib.MetricMutable>>	metrics() Get the metrics
String	name()
org.apache.hadoop.metrics2.lib.MetricMutableCounterInt	newCounter(String name, String description, int initValue) Create a mutable integer counter
org.apache.hadoop.metrics2.lib.MetricMutableCounterLong	newCounter(String name, String description, long initValue) Create a mutable long integer counter
org.apache.hadoop.metrics2.lib.MetricMutableGaugeInt	newGauge(String name, String description, int initValue) Create a mutable integer gauge
org.apache.hadoop.metrics2.lib.MetricMutableGaugeLong	newGauge(String name, String description, long initValue) Create a mutable long integer gauge
MetricMutableHistogram	newHistogram(String name) Create a new histogram.
MetricMutableHistogram	newHistogram(String name, String desc) Create a new histogram.
MetricMutableQuantiles	newQuantile(String name) Create a new MutableQuantile(A more accurate histogram).
MetricMutableQuantiles	newQuantile(String name, String desc) Create a new MutableQuantile(A more accurate histogram).
org.apache.hadoop.metrics2.lib.MetricMutableStat	newStat(String name) Create a mutable metric with stats using the name only
org.apache.hadoop.metrics2.lib.MetricMutableStat	newStat(String name, String description, String sampleName, String valueName) Create a mutable metric with stats
org.apache.hadoop.metrics2.lib.MetricMutableStat	newStat(String name, String description, String sampleName, String valueName, boolean extended) Create a mutable metric with stats
void	removeMetric(String name) Removes metric by name
DynamicMetricsRegistry	setContext(String name) Set the metrics context tag
void	snapshot(org.apache.hadoop.metrics2.MetricsRecordBuilder builder, boolean all) Sample all the mutable metrics and put the snapshot in the builder
DynamicMetricsRegistry	tag(String name, String description, String value) Add a tag to the metrics
DynamicMetricsRegistry	tag(String name, String description, String value, boolean override) Add a tag to the metrics
Set<Map.Entry<String,org.apache.hadoop.metrics2.MetricsTag>>	tags() Get the tags

Methods inherited from class java.lang.Object

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

Field Detail

CONTEXT_KEY

public static final String CONTEXT_KEY

key for the context tag

See Also:

Constant Field Values

CONTEXT_DESC

public static final String CONTEXT_DESC

description for the context tag

See Also:

Constant Field Values

Constructor Detail

DynamicMetricsRegistry

public DynamicMetricsRegistry(String name)

Construct the registry with a record name

Parameters:

name - of the record of the metrics

DynamicMetricsRegistry

public DynamicMetricsRegistry(String name,
                      org.apache.hadoop.metrics2.lib.MetricMutableFactory factory)

Construct the registry with a name and a metric factory

Parameters:

name - of the record of the metrics

factory - for creating new mutable metrics

Method Detail

name

public String name()

Returns:

the name of the metrics registry

get

public org.apache.hadoop.metrics2.lib.MetricMutable get(String name)

Get a metric by name

Parameters:

name - of the metric

Returns:

the metric object

newCounter

public org.apache.hadoop.metrics2.lib.MetricMutableCounterInt newCounter(String name,
                                                                String description,
                                                                int initValue)

Create a mutable integer counter

Parameters:

name - of the metric

description - of the metric

initValue - of the metric

Returns:

a new counter object

newCounter

public org.apache.hadoop.metrics2.lib.MetricMutableCounterLong newCounter(String name,
                                                                 String description,
                                                                 long initValue)

Create a mutable long integer counter

Parameters:

name - of the metric

description - of the metric

initValue - of the metric

Returns:

a new counter object

newGauge

public org.apache.hadoop.metrics2.lib.MetricMutableGaugeInt newGauge(String name,
                                                            String description,
                                                            int initValue)

Create a mutable integer gauge

Parameters:

name - of the metric

description - of the metric

initValue - of the metric

Returns:

a new gauge object

newGauge

public org.apache.hadoop.metrics2.lib.MetricMutableGaugeLong newGauge(String name,
                                                             String description,
                                                             long initValue)

Create a mutable long integer gauge

Parameters:

name - of the metric

description - of the metric

initValue - of the metric

Returns:

a new gauge object

newStat

public org.apache.hadoop.metrics2.lib.MetricMutableStat newStat(String name,
                                                       String description,
                                                       String sampleName,
                                                       String valueName,
                                                       boolean extended)

Create a mutable metric with stats

Parameters:

name - of the metric

description - of the metric

sampleName - of the metric (e.g., "ops")

valueName - of the metric (e.g., "time" or "latency")

extended - produce extended stat (stdev, min/max etc.) if true.

Returns:

a new metric object

newStat

public org.apache.hadoop.metrics2.lib.MetricMutableStat newStat(String name,
                                                       String description,
                                                       String sampleName,
                                                       String valueName)

Create a mutable metric with stats

Parameters:

name - of the metric

description - of the metric

sampleName - of the metric (e.g., "ops")

valueName - of the metric (e.g., "time" or "latency")

Returns:

a new metric object

newStat

public org.apache.hadoop.metrics2.lib.MetricMutableStat newStat(String name)

Create a mutable metric with stats using the name only

Parameters:

name - of the metric

Returns:

a new metric object

newHistogram

public MetricMutableHistogram newHistogram(String name)

Create a new histogram.

Parameters:

name - Name of the histogram.

Returns:

A new MutableHistogram

newHistogram

public MetricMutableHistogram newHistogram(String name,
                                  String desc)

Create a new histogram.

Parameters:

name - The name of the histogram

desc - The description of the data in the histogram.

Returns:

A new MutableHistogram

newQuantile

public MetricMutableQuantiles newQuantile(String name)

Create a new MutableQuantile(A more accurate histogram).

Parameters:

name - The name of the histogram

Returns:

a new MutableQuantile

newQuantile

public MetricMutableQuantiles newQuantile(String name,
                                 String desc)

Create a new MutableQuantile(A more accurate histogram).

Parameters:

name - The name of the histogram

desc - Description of the data.

Returns:

a new MutableQuantile

setContext

public DynamicMetricsRegistry setContext(String name)

Set the metrics context tag

Parameters:

name - of the context

Returns:

the registry itself as a convenience

tag

public DynamicMetricsRegistry tag(String name,
                         String description,
                         String value)

Add a tag to the metrics

Parameters:

name - of the tag

description - of the tag

value - of the tag

Returns:

the registry (for keep adding tags)

tag

public DynamicMetricsRegistry tag(String name,
                         String description,
                         String value,
                         boolean override)

Add a tag to the metrics

Parameters:

name - of the tag

description - of the tag

value - of the tag

override - existing tag if true

Returns:

the registry (for keep adding tags)

tags

public Set<Map.Entry<String,org.apache.hadoop.metrics2.MetricsTag>> tags()

Get the tags

Returns:

the tags set

metrics

public Set<Map.Entry<String,org.apache.hadoop.metrics2.lib.MetricMutable>> metrics()

Get the metrics

Returns:

the metrics set

snapshot

public void snapshot(org.apache.hadoop.metrics2.MetricsRecordBuilder builder,
            boolean all)

Sample all the mutable metrics and put the snapshot in the builder

Parameters:

builder - to contain the metrics snapshot

all - get all the metrics even if the values are not changed.

removeMetric

public void removeMetric(String name)

Removes metric by name

Parameters:

name - name of the metric to remove

getLongGauge

public org.apache.hadoop.metrics2.lib.MetricMutableGaugeLong getLongGauge(String gaugeName,
                                                                 long potentialStartingValue)

Get a MetricMutableGaugeLong from the storage. If it is not there atomically put it.

Parameters:

gaugeName - name of the gauge to create or get.

potentialStartingValue - value of the new counter if we have to create it.

Returns:

a metric object

getLongCounter

public org.apache.hadoop.metrics2.lib.MetricMutableCounterLong getLongCounter(String counterName,
                                                                     long potentialStartingValue)

Get a MetricMutableCounterLong from the storage. If it is not there atomically put it.

Parameters:

counterName - Name of the counter to get

potentialStartingValue - starting value if we have to create a new counter

Returns:

a metric object

getHistogram

public MetricMutableHistogram getHistogram(String histoName)

getQuantile

public MetricMutableQuantiles getQuantile(String histoName)

clearMetrics

public void clearMetrics()