Package io.prometheus.metrics.instrumentation.caffeine

Class CacheMetricsCollector

Object

CacheMetricsCollector

All Implemented Interfaces:

MultiCollector

public class CacheMetricsCollector
extends Object
implements MultiCollector

Collect metrics from Caffeine's com.github.benmanes.caffeine.cache.Cache.

 // Note that `recordStats()` is required to gather non-zero statistics
 Cache<String, String> cache = Caffeine.newBuilder().recordStats().build();
 CacheMetricsCollector cacheMetrics = new CacheMetricsCollector();
 PrometheusRegistry.defaultRegistry.register(cacheMetrics);
 cacheMetrics.addCache("mycache", cache);

 

Exposed metrics are labeled with the provided cache name.

With the example above, sample metric names would be:

     caffeine_cache_hit_total{cache="mycache"} 10.0
     caffeine_cache_miss_total{cache="mycache"} 3.0
     caffeine_cache_requests_total{cache="mycache"} 13.0
     caffeine_cache_eviction_total{cache="mycache"} 1.0
     caffeine_cache_estimated_size{cache="mycache"} 5.0
 

Additionally, if the cache includes a loader, the following metrics would be provided:

     caffeine_cache_load_failure_total{cache="mycache"} 2.0
     caffeine_cache_loads_total{cache="mycache"} 7.0
     caffeine_cache_load_duration_seconds_count{cache="mycache"} 7.0
     caffeine_cache_load_duration_seconds_sum{cache="mycache"} 0.0034
 

Constructor Summary

Constructors

Constructor	Description
CacheMetricsCollector()

Method Summary

Modifier and Type	Method	Description
void	addCache(String cacheName, AsyncCache<?,?> cache)	Add or replace the cache with the given name.
void	addCache(String cacheName, Cache<?,?> cache)	Add or replace the cache with the given name.
void	clear()	Remove all caches.
MetricSnapshots	collect()	Called when the Prometheus server scrapes metrics.
Cache<?,?>	removeCache(String cacheName)	Remove the cache with the given name.

Methods inherited from class Object

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

Methods inherited from interface MultiCollector

collect, collect, collect, getPrometheusNames

Constructor Details

CacheMetricsCollector

public CacheMetricsCollector()

Method Details

addCache

public void addCache(String cacheName,
 Cache<?,?> cache)

Add or replace the cache with the given name.

Any references any previous cache with this name is invalidated.

Parameters:

cacheName - The name of the cache, will be the metrics label value

cache - The cache being monitored

addCache

public void addCache(String cacheName,
 AsyncCache<?,?> cache)

Add or replace the cache with the given name.

Any references any previous cache with this name is invalidated.

Parameters:

cacheName - The name of the cache, will be the metrics label value

cache - The cache being monitored

removeCache

public Cache<?,?> removeCache(String cacheName)

Remove the cache with the given name.

Any references to the cache are invalidated.

Parameters:

cacheName - cache to be removed

clear

public void clear()

Remove all caches.

Any references to all caches are invalidated.

collect

public MetricSnapshots collect()

Description copied from interface: MultiCollector

Called when the Prometheus server scrapes metrics.

Specified by:

collect in interface MultiCollector