Package io.micrometer.core.instrument.binder.cache

Class JCacheMetrics<K,V,C extends javax.cache.Cache<K,V>>

java.lang.Object

io.micrometer.core.instrument.binder.cache.CacheMeterBinder<C>

io.micrometer.core.instrument.binder.cache.JCacheMetrics<K,V,C>

All Implemented Interfaces:

MeterBinder

@NonNullApi
@NonNullFields
public class JCacheMetrics<K,V,C extends javax.cache.Cache<K,V>>
extends CacheMeterBinder<C>

Collect metrics on JSR-107 JCache caches, including detailed metrics on manual puts and removals. See https://github.com/jsr107/demo/blob/master/src/test/java/javax/cache/core/StatisticsExample.java

Note that JSR-107 does not provide any insight into the size or estimated size of the cache, so the size metric of a JCache cache will always report 0.

Constructor Summary

Constructors

Constructor	Description
JCacheMetrics(C cache, Iterable<Tag> tags)

Method Summary

Modifier and Type	Method	Description
protected void	bindImplementationSpecificMetrics(MeterRegistry registry)	Bind detailed metrics that are particular to the cache implementation, e.g.
protected Long	evictionCount()
protected long	hitCount()
protected Long	missCount()
static <K, V, C extends javax.cache.Cache<K, V>> C	monitor(MeterRegistry registry, C cache, Iterable<Tag> tags)	Record metrics on a JCache cache.
static <K, V, C extends javax.cache.Cache<K, V>> C	monitor(MeterRegistry registry, C cache, String... tags)	Record metrics on a JCache cache.
protected long	putCount()	The put mechanism is unimportant - this count applies to entries added to the cache according to a pre-defined load function such as exists in Guava/Caffeine caches as well as manual puts.
protected Long	size()	MOST cache implementations provide a means of retrieving the number of entries.

Methods inherited from class io.micrometer.core.instrument.binder.cache.CacheMeterBinder

bindTo, getCache, getTagsWithCacheName

Methods inherited from class java.lang.Object

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

Constructor Details

JCacheMetrics

public JCacheMetrics(C cache,
 Iterable<Tag> tags)

Method Details

monitor

public static <K,
V,
C extends javax.cache.Cache<K,
V>>
C monitor(MeterRegistry registry,
 C cache,
 String... tags)

Record metrics on a JCache cache.

Type Parameters:

C - The cache type.

K - The cache key type.

V - The cache value type.

Parameters:

registry - The registry to bind metrics to.

cache - The cache to instrument.

tags - Tags to apply to all recorded metrics. Must be an even number of arguments representing key/value pairs of tags.

Returns:

The instrumented cache, unchanged. The original cache is not wrapped or proxied in any way.

monitor

public static <K,
V,
C extends javax.cache.Cache<K,
V>>
C monitor(MeterRegistry registry,
 C cache,
 Iterable<Tag> tags)

Record metrics on a JCache cache.

Type Parameters:

C - The cache type.

K - The cache key type.

V - The cache value type.

Parameters:

registry - The registry to bind metrics to.

cache - The cache to instrument.

tags - Tags to apply to all recorded metrics.

Returns:

The instrumented cache, unchanged. The original cache is not wrapped or proxied in any way.

size

protected Long size()

Description copied from class: CacheMeterBinder

MOST cache implementations provide a means of retrieving the number of entries. Even if

Specified by:

size in class CacheMeterBinder<C extends javax.cache.Cache<K,V>>

Returns:

Total number of cache entries. This value may go up or down with puts, removes, and evictions. Returns null if the cache implementation does not provide a way to track cache size.

hitCount

protected long hitCount()

Specified by:

hitCount in class CacheMeterBinder<C extends javax.cache.Cache<K,V>>

Returns:

Get requests that resulted in a "hit" against an existing cache entry. Monotonically increasing hit count.

missCount

protected Long missCount()

Specified by:

missCount in class CacheMeterBinder<C extends javax.cache.Cache<K,V>>

Returns:

Get requests that resulted in a "miss", or didn't match an existing cache entry. Monotonically increasing count. Returns null if the cache implementation does not provide a way to track miss count, especially in distributed caches.

evictionCount

protected Long evictionCount()

Specified by:

evictionCount in class CacheMeterBinder<C extends javax.cache.Cache<K,V>>

Returns:

Total number of entries that have been evicted from the cache. Monotonically increasing eviction count. Returns null if the cache implementation does not support eviction, or does not provide a way to track the eviction count.

putCount

protected long putCount()

Description copied from class: CacheMeterBinder

The put mechanism is unimportant - this count applies to entries added to the cache according to a pre-defined load function such as exists in Guava/Caffeine caches as well as manual puts. Note that Guava/Caffeine caches don't count manual puts.

Specified by:

putCount in class CacheMeterBinder<C extends javax.cache.Cache<K,V>>

Returns:

Total number of entries added to the cache. Monotonically increasing count.

bindImplementationSpecificMetrics

protected void bindImplementationSpecificMetrics(MeterRegistry registry)

Description copied from class: CacheMeterBinder

Bind detailed metrics that are particular to the cache implementation, e.g. load duration for Caffeine caches, heap and disk size for EhCache caches. These metrics are above and beyond the basic set of metrics that is common to all caches.

Specified by:

bindImplementationSpecificMetrics in class CacheMeterBinder<C extends javax.cache.Cache<K,V>>

Parameters:

registry - The registry to bind metrics to.