DynamicMetricsRegistry (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.metrics2.lib.DynamicMetricsRegistry

```
@InterfaceAudience.Private
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 implementation is substituted with thread-safe map, as we allow dynamic metrics additions/removals.

Constructor Summary

Constructors
Constructor and Description
`DynamicMetricsRegistry(org.apache.hadoop.metrics2.MetricsInfo info)` Construct the registry with a metadata object
`DynamicMetricsRegistry(String name)` Construct the registry with a record name

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(String name, long value)` Add sample to a stat metric by name.
`void`	`clearMetrics()`
`org.apache.hadoop.metrics2.lib.MutableMetric`	`get(String name)` Get a metric by name
`MutableFastCounter`	`getCounter(String counterName, long potentialStartingValue)` Get a MetricMutableCounterLong from the storage.
`org.apache.hadoop.metrics2.lib.MutableGaugeLong`	`getGauge(String gaugeName, long potentialStartingValue)` Get a MetricMutableGaugeLong from the storage.
`MutableHistogram`	`getHistogram(String histoName)`
`org.apache.hadoop.metrics2.MetricsTag`	`getTag(String name)` Get a tag by name
`org.apache.hadoop.metrics2.MetricsInfo`	`info()`
`MutableFastCounter`	`newCounter(org.apache.hadoop.metrics2.MetricsInfo info, long iVal)` Create a mutable long integer counter
`MutableFastCounter`	`newCounter(String name, String desc, long iVal)` Create a mutable long integer counter
`org.apache.hadoop.metrics2.lib.MutableGaugeLong`	`newGauge(org.apache.hadoop.metrics2.MetricsInfo info, long iVal)` Create a mutable long integer gauge
`org.apache.hadoop.metrics2.lib.MutableGaugeLong`	`newGauge(String name, String desc, long iVal)` Create a mutable long integer gauge
`MutableHistogram`	`newHistogram(String name)` Create a new histogram.
`MutableHistogram`	`newHistogram(String name, String desc)` Create a new histogram.
`org.apache.hadoop.metrics2.lib.MutableRate`	`newRate(String name)` Create a mutable rate metric
`org.apache.hadoop.metrics2.lib.MutableRate`	`newRate(String name, String description)` Create a mutable rate metric
`org.apache.hadoop.metrics2.lib.MutableRate`	`newRate(String name, String desc, boolean extended)` Create a mutable rate metric (for throughput measurement)
`org.apache.hadoop.metrics2.lib.MutableRate`	`newRate(String name, String desc, boolean extended, boolean returnExisting)`
`MutableSizeHistogram`	`newSizeHistogram(String name)` Create a new histogram with size range counts.
`MutableSizeHistogram`	`newSizeHistogram(String name, String desc)` Create a new histogram with size range counts.
`org.apache.hadoop.metrics2.lib.MutableStat`	`newStat(String name, String desc, String sampleName, String valueName)` Create a mutable metric with stats
`org.apache.hadoop.metrics2.lib.MutableStat`	`newStat(String name, String desc, String sampleName, String valueName, boolean extended)` Create a mutable metric with stats
`MutableTimeHistogram`	`newTimeHistogram(String name)` Create a new histogram with time range counts.
`MutableTimeHistogram`	`newTimeHistogram(String name, String desc)` Create a new histogram with time range counts.
`void`	`removeHistogramMetrics(String baseName)`
`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(org.apache.hadoop.metrics2.MetricsInfo info, String value)`
`DynamicMetricsRegistry`	`tag(org.apache.hadoop.metrics2.MetricsInfo info, String value, boolean override)` Add a tag to the metrics
`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
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

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(org.apache.hadoop.metrics2.MetricsInfo info)
```
  Construct the registry with a metadata object
  
  Parameters:
  info - the info object for the metrics record/group

Method Detail

info

public org.apache.hadoop.metrics2.MetricsInfo info()

Returns:: the info object of the metrics registry

get
```
public org.apache.hadoop.metrics2.lib.MutableMetric get(String name)
```
Get a metric by name

Parameters:
name - of the metric

Returns:
the metric object

getTag
```
public org.apache.hadoop.metrics2.MetricsTag getTag(String name)
```
Get a tag by name

Parameters:
name - of the tag

Returns:
the tag object

newCounter

public MutableFastCounter newCounter(String name,
                            String desc,
                            long iVal)

Create a mutable long integer counter

Parameters:: name - of the metric; desc - metric description; iVal - initial value
Returns:: a new counter object

newCounter
```
public MutableFastCounter newCounter(org.apache.hadoop.metrics2.MetricsInfo info,
                            long iVal)
```
Create a mutable long integer counter

Parameters:
info - metadata of the metric
iVal - initial value

Returns:
a new counter object

newGauge

public org.apache.hadoop.metrics2.lib.MutableGaugeLong newGauge(String name,
                                                       String desc,
                                                       long iVal)

Create a mutable long integer gauge

Parameters:: name - of the metric; desc - metric description; iVal - initial value
Returns:: a new gauge object

newGauge

public org.apache.hadoop.metrics2.lib.MutableGaugeLong newGauge(org.apache.hadoop.metrics2.MetricsInfo info,
                                                       long iVal)

Create a mutable long integer gauge

Parameters:: info - metadata of the metric; iVal - initial value
Returns:: a new gauge object

newStat

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

Create a mutable metric with stats

Parameters:: name - of the metric; desc - metric description; 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 mutable stat metric object

newStat

public org.apache.hadoop.metrics2.lib.MutableStat newStat(String name,
                                                 String desc,
                                                 String sampleName,
                                                 String valueName)

Create a mutable metric with stats

Parameters:: name - of the metric; desc - metric description; sampleName - of the metric (e.g., "Ops"); valueName - of the metric (e.g., "Time" or "Latency")
Returns:: a new mutable metric object

newRate
```
public org.apache.hadoop.metrics2.lib.MutableRate newRate(String name)
```
Create a mutable rate metric

Parameters:
name - of the metric

Returns:
a new mutable metric object

newRate

public org.apache.hadoop.metrics2.lib.MutableRate newRate(String name,
                                                 String description)

Create a mutable rate metric

Parameters:: name - of the metric; description - of the metric
Returns:: a new mutable rate metric object

newRate

public org.apache.hadoop.metrics2.lib.MutableRate newRate(String name,
                                                 String desc,
                                                 boolean extended)

Create a mutable rate metric (for throughput measurement)

Parameters:: name - of the metric; desc - description; extended - produce extended stat (stdev/min/max etc.) if true
Returns:: a new mutable rate metric object

newRate

@InterfaceAudience.Private
public org.apache.hadoop.metrics2.lib.MutableRate newRate(String name,
                                                                           String desc,
                                                                           boolean extended,
                                                                           boolean returnExisting)

newHistogram
```
public MutableHistogram newHistogram(String name)
```
Create a new histogram.

Parameters:
name - Name of the histogram.

Returns:
A new MutableHistogram

newHistogram
```
public MutableHistogram 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

newTimeHistogram
```
public MutableTimeHistogram newTimeHistogram(String name)
```
Create a new histogram with time range counts.

Parameters:
name - Name of the histogram.

Returns:
A new MutableTimeHistogram

newTimeHistogram
```
public MutableTimeHistogram newTimeHistogram(String name,
                                    String desc)
```
Create a new histogram with time range counts.

Parameters:
name - The name of the histogram
desc - The description of the data in the histogram.

Returns:
A new MutableTimeHistogram

newSizeHistogram
```
public MutableSizeHistogram newSizeHistogram(String name)
```
Create a new histogram with size range counts.

Parameters:
name - Name of the histogram.

Returns:
A new MutableSizeHistogram

newSizeHistogram
```
public MutableSizeHistogram newSizeHistogram(String name,
                                    String desc)
```
Create a new histogram with size range counts.

Parameters:
name - The name of the histogram
desc - The description of the data in the histogram.

Returns:
A new MutableSizeHistogram

add
```
public void add(String name,
       long value)
```
Add sample to a stat metric by name.

Parameters:
name - of the metric
value - of the snapshot to add

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)

tag

public DynamicMetricsRegistry tag(org.apache.hadoop.metrics2.MetricsInfo info,
                         String value,
                         boolean override)

Add a tag to the metrics

Parameters:: info - metadata of the tag; value - of the tag; override - existing tag if true
Returns:: the registry (for keep adding tags etc.)

tag

public DynamicMetricsRegistry tag(org.apache.hadoop.metrics2.MetricsInfo info,
                         String value)

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.

toString
```
public String toString()
```
Overrides:

toString in class Object

removeMetric
```
public void removeMetric(String name)
```
Removes metric by name

Parameters:
name - name of the metric to remove

removeHistogramMetrics

public void removeHistogramMetrics(String baseName)

getGauge
```
public org.apache.hadoop.metrics2.lib.MutableGaugeLong getGauge(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 gauge if we have to create it.

getCounter
```
public MutableFastCounter getCounter(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

getHistogram

public MutableHistogram getHistogram(String histoName)

clearMetrics
```
public void clearMetrics()
```

Class DynamicMetricsRegistry

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DynamicMetricsRegistry

DynamicMetricsRegistry

Method Detail

info

get

getTag

newCounter

newCounter

newGauge

newGauge

newStat

newStat

newRate

newRate

newRate

newRate

newHistogram

newHistogram

newTimeHistogram

newTimeHistogram

newSizeHistogram

newSizeHistogram

add

setContext

tag

tag

tag

tag

snapshot

toString

removeMetric

removeHistogramMetrics

getGauge

getCounter

getHistogram

clearMetrics