1. A method of routing directory service operations in a directory service network comprising a plurality of directory servers, wherein at least one of the plurality of directory servers includes a non-persistent storage mechanism, the method comprising: receiving a directory service operation; determining one or more of the plurality of directory servers that are available to process the directory service operation; selecting one of the one or more available directory servers, based at least in part on the determination of availability; and routing the directory service operation to the selected directory server.