1. An apparatus for managing failover in a clustered system, the clustered system comprising a plurality of sub-clusters connected with one another by a first set of links, each sub-cluster comprising a plurality of nodes connected with one another by a second set of links, the apparatus comprising: a processor; a non-transitory computer-readable medium storing computer-executable code that when executed by the processor implements a plurality of units comprising: a determination unit configured to determine, by using at least one of the second set of links, that a suspect node within a same sub-cluster as another node has stopped; a notification unit configured to, in response to the determination, transmit a lease relinquish message on behalf of the suspect node; and a judging unit configured to check whether the another node has authority to make a decision on behalf of the same sub-cluster by accessing and inquiring about authority information, wherein the notification unit is configured to transmit the lease relinquish message in response to the judging unit determining that the another node has authority.