How to expose cache statistics for Guava Cache

Question

I'm using spring boot 1.5 and I cannot expose guava cache statistics in /prometheus endpoint. Eventually I can expose it as JMX but then I dont know how to wire these things up. Is there some easier way how to do it?

I am creating the cache with cache builder as following:

    @Bean
    @Primary
    public CacheManager cacheManager() {
        final GuavaCacheManager cacheManager = new GuavaCacheManager();
        final CacheBuilder<Object, Object> cacheBuilder = CacheBuilder.newBuilder()
                .maximumSize(5000)
                .recordStats()
                .expireAfterWrite(1, TimeUnit.HOURS);
        cacheManager.setCacheBuilder(cacheBuilder);
        cacheManager.setCacheNames(Lists.newArrayList("TEST_CACHE"));
        return cacheManager;
    }

I am using .recordStats() method as well.

Answer 1

You can monitor the Guava chache metrics by using the GuavaCacheMetrics binder

GuavaCacheBuilder.monitor(meterRegistry, aCache, "myCacheName")

Notice since you are using a cache builder with the CacheManager you would need to make that monitor call for each individual cache.

There are other ways to approach this, and the CacheManager is automatically instrumented in SpringBot 2.x I believe. So upgrading will give you a simpler integration.