Large DDoS botnets will have hundreds of thousands of return-path-capable IP addresses. Your temporary blocks will have to be very sensitive (i.e. trigger on a relatively small number of requests within the time window) for an application-level DDoS to be usefully mitigated.
Temporary blocks if and when you are actually being DDoSed, presumably?
Large DDoS botnets will have hundreds of thousands of return-path-capable IP addresses. Your temporary blocks will have to be very sensitive (i.e. trigger on a relatively small number of requests within the time window) for an application-level DDoS to be usefully mitigated.