[QUESTION]: Too high missed rate?

[Maxim Geraskin]

Question.

I have a test:

func TestRistretto_Get(t *testing.T) {
	require := require.New(t)

	const CacheSize = 10_000

	m, err := ristretto.NewCache(&ristretto.Config{
		NumCounters: CacheSize / 10, // number of keys to track frequency
		MaxCost:     CacheSize,      // maximum cost of cache
		BufferItems: 64,             // number of keys per Get buffer.
	})
	require.NoError(err)

	numFound := 0
	numMissed := 0

	for i := 0; i < CacheSize; i++ {
		k := fmt.Sprint(i)
		for {
			r := m.Set(k, i+1, 1)
			m.Wait()
			if r {
				break
			}
		}
		_, ok := m.Get(k)
		if !ok {
			numMissed++
		} else {
			numFound++
		}
	}
	fmt.Println("numOk:", numFound, "numMissed:", numMissed)
	require.NotNil(t)
}

It prints numOk: 3494 numMissed: 6506. Is it ok that so many keys are missed?