Package com.broadleafcommerce.common.extension.cache.caffeine

Class CaffeineCacheMetrics

java.lang.Object

io.micrometer.core.instrument.binder.cache.CacheMeterBinder

com.broadleafcommerce.common.extension.cache.caffeine.CaffeineCacheMetrics

All Implemented Interfaces:

io.micrometer.core.instrument.binder.MeterBinder

public class CaffeineCacheMetrics
extends io.micrometer.core.instrument.binder.cache.CacheMeterBinder

A helper class for monitoring and exposing Caffeine cache metrics through Micrometer.

This implementation utilizes a background thread to refresh the cache statistics (e.g., hit/miss counts, estimated size, and eviction weight) upon a scrape request. By offloading these calculations—particularly the aggregation of concurrent LongAdder arrays in cache.stats() and the traversal of the eviction policy—we prevent blocking the main request threads (such as Tomcat HTTP threads) during Micrometer scrapes.

If a refresh is already in progress, additional scrape requests will use the currently available metrics and will not spawn additional tasks.

Additionally, if the cache is configured with a weigher that tracks byte sizes (such as with a CaffeineProxy), this binder exposes a cache.memory.used gauge to accurately report the total on-heap memory footprint of the cache region.

Constructor Summary

Constructors

Constructor	Description
CaffeineCacheMetrics(ExecutorService refreshExecutor, com.github.benmanes.caffeine.cache.Cache<?,?> cache, String name, Iterable<io.micrometer.core.instrument.Tag> tags)

Method Summary

Modifier and Type	Method	Description
protected void	bindImplementationSpecificMetrics(io.micrometer.core.instrument.MeterRegistry registry)
protected Long	evictionCount()
protected long	hitCount()
protected Long	missCount()
static CaffeineCacheMetrics	monitor(io.micrometer.core.instrument.MeterRegistry registry, ExecutorService refreshExecutor, com.github.benmanes.caffeine.cache.Cache<?,?> cache, String name, String... tags)
protected long	putCount()
protected Long	size()

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

CaffeineCacheMetrics

public CaffeineCacheMetrics(ExecutorService refreshExecutor,
 com.github.benmanes.caffeine.cache.Cache<?,?> cache,
 String name,
 Iterable<io.micrometer.core.instrument.Tag> tags)

Method Details

monitor

public static CaffeineCacheMetrics monitor(io.micrometer.core.instrument.MeterRegistry registry,
 ExecutorService refreshExecutor,
 com.github.benmanes.caffeine.cache.Cache<?,?> cache,
 String name,
 String... tags)

size

protected Long size()

Specified by:

size in class io.micrometer.core.instrument.binder.cache.CacheMeterBinder

hitCount

protected long hitCount()

Specified by:

hitCount in class io.micrometer.core.instrument.binder.cache.CacheMeterBinder

missCount

protected Long missCount()

Specified by:

missCount in class io.micrometer.core.instrument.binder.cache.CacheMeterBinder

evictionCount

protected Long evictionCount()

Specified by:

evictionCount in class io.micrometer.core.instrument.binder.cache.CacheMeterBinder

putCount

protected long putCount()

Specified by:

putCount in class io.micrometer.core.instrument.binder.cache.CacheMeterBinder

bindImplementationSpecificMetrics

protected void bindImplementationSpecificMetrics(io.micrometer.core.instrument.MeterRegistry registry)

Specified by:

bindImplementationSpecificMetrics in class io.micrometer.core.instrument.binder.cache.CacheMeterBinder