1. A method for updating resource records, the method comprising: in a network node, generating an update-request message that includes: a set of resource-record updates, and a requested lease, which specifies a time-to-live for which a name server is being requested by the network node to store the set of resource-record updates; sending the update-request message from the network node to the name server, which is part of a distributed system that provides a global naming service; and receiving a response message at the network node from the name server, wherein the response message is associated with the update-request message, and wherein the response message includes a granted lease which specifies a time-to-live for which the name server is expected to store the resource-records updates.