Very simply test to show the cost of stats in guava cache

gistfile1.java

import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 */
public class Test {

    static final long WARMUP = 1000000;
    static final long RUN = 50000000;
    static final int THREADS = 5;

    public static void main(String[] args) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException, InterruptedException {

        CacheBuilder<Object, Object> cacheBuilder = CacheBuilder.newBuilder();
        Method cacheBuilderDisableStatsMethodX = CacheBuilder.class.getDeclaredMethod("disableStats");
        cacheBuilderDisableStatsMethodX.setAccessible(true);
        cacheBuilderDisableStatsMethodX.invoke(cacheBuilder);
        Cache<String, String> noStatsCache = cacheBuilder.build();
        runTest(noStatsCache, "no stats");

        Cache<String, String> statsCache = CacheBuilder.newBuilder().build();
        runTest(statsCache, "with stats");
    }

    private static void runTest(final Cache<String, String> cache, String type) throws InterruptedException {
        ThreadPoolExecutor executorService = (ThreadPoolExecutor) Executors.newFixedThreadPool(THREADS);
        executorService.prestartAllCoreThreads();

        System.out.println("--- Starting: (" + type + ")");
        init(cache);
        System.out.println("Start Warmup");
        execute(cache, WARMUP);
        System.out.println("Done Warmup");

        System.out.println("Start Test");
        long start = System.currentTimeMillis();
        for (int i = 0; i < THREADS; i++) {
            executorService.submit(new Runnable() {
                @Override
                public void run() {
                    execute(cache, RUN);
                }
            });
        }
        executorService.shutdown();
        executorService.awaitTermination(10000, TimeUnit.SECONDS);
        long took = System.currentTimeMillis() - start;
        System.out.println("--- Done: (" + type + "), took: " + took + "ms");
    }

    static void init(Cache<String, String> cache) {
        for (int i = 0; i < 100; i++) {
            cache.put(Integer.toString(i), Integer.toString(i));
        }
    }

    static void execute(Cache<String, String> cache, long count) {
        for (long i = 0; i < count; i++) {
            cache.getIfPresent("1");
        }
    }
}