Abstract: Methods, apparatus and computer software products implement embodiments of the present invention that include receiving requests from clients to access a corpus of data that is replicated on a group of servers, and distributing the requests among the servers for execution in accordance with an allocation function, which indicates a respective fraction of the requests that is to be assigned to each of the servers for execution. Respective cache miss rates incurred by the servers in responding to the requests that are distributed to each of the servers are measured, and the allocation function is adjusted responsively to the cache miss rates.