Package org.apache.hadoop.metrics2.util

Class MetricsCache

java.lang.Object

org.apache.hadoop.metrics2.util.MetricsCache

@Public
@Evolving
public class MetricsCache
extends Object

A metrics cache for sinks that don't support sparse updates.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MetricsCache.Record	Cached record

Constructor Summary

Constructors

Constructor	Description
MetricsCache()
MetricsCache(int maxRecsPerName)	Construct a metrics cache

Method Summary

Modifier and Type	Method	Description
MetricsCache.Record	get(String name, Collection<MetricsTag> tags)	Get the cached record
MetricsCache.Record	update(MetricsRecord mr)	Update the cache and return the current cache record
MetricsCache.Record	update(MetricsRecord mr, boolean includingTags)	Update the cache and return the current cached record

Methods inherited from class java.lang.Object

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

Constructor Details

MetricsCache

public MetricsCache()

MetricsCache

public MetricsCache(int maxRecsPerName)

Construct a metrics cache

Parameters:

maxRecsPerName - limit of the number records per record name

Method Details

update

public MetricsCache.Record update(MetricsRecord mr,
 boolean includingTags)

Update the cache and return the current cached record

Parameters:

mr - the update record

includingTags - cache tag values (for later lookup by name) if true

Returns:

the updated cache record

update

public MetricsCache.Record update(MetricsRecord mr)

Update the cache and return the current cache record

Parameters:

mr - the update record

Returns:

the updated cache record

get

public MetricsCache.Record get(String name,
 Collection<MetricsTag> tags)

Get the cached record

Parameters:

name - of the record

tags - of the record

Returns:

the cached record or null