Counter Size and Counter Overflow
- We must select counters large enough for avoiding overflow.
- Size is 4 bits/counter suggested by Poisson approximation.
- Average load implementing k = (ln 2)m/n counters is ln 2.
- Probability a counter has load minimum 16:≈e-ln2(ln 2)16/16!≈6.78E-17
- We consider 4 bits/counter for comparisons.
- When a counter does overflow, it may be arrived at its maximum value.
- This situation can later cause a false negative only if eventually the counter goes down to 0 when it should have remained at nonzero.
- The expected time to this situation is very large but is something we need to keep in mind for any application that does not permit false negatives.
- For avoiding counter overflow, its size must be sufficiently large. It was found that 4 bits per counter are sufficient.
Published on 03-Jan-2020 10:27:52