Number of times a requested item was found in the cache. |

.. _manual-caffeine:

##################### Instrumenting Caffeine #####################

.. highlight:: text

.. rubric:: The metrics-caffeine module provides MetricsStatsCounter, a metrics listener for Caffeine_ caches:

.. _Caffeine: https://github.com/ben-manes/caffeine

.. code-block:: java

LoadingCache<Integer, Integer> cache = Caffeine.newBuilder()
    .recordStats(() -> new MetricsStatsCounter(registry, "cache"))
    .build(key -> key);

The listener publishes these metrics:

+---------------------------+----------------------------------------------------------------------+ | hits | Number of times a requested item was found in the cache. | +---------------------------+----------------------------------------------------------------------+ | misses | Number of times a requested item was not found in the cache. | +---------------------------+----------------------------------------------------------------------+ | loads-success | Timer for successful loads into cache. | +---------------------------+----------------------------------------------------------------------+ | loads-failure | Timer for failed loads into cache. | +---------------------------+----------------------------------------------------------------------+ | evictions | Histogram of eviction weights . | +---------------------------+----------------------------------------------------------------------+ | evictions-weight | Total weight of evicted entries. | +---------------------------+----------------------------------------------------------------------+ | evictions.<CAUSE> | Histogram of eviction weights for each RemovalCause | +---------------------------+----------------------------------------------------------------------+