interface Agent {
    HostnameSeq all_agent_locations( )
        raises(Fail);
    RepositoryIdSeq all_repository_ids( )
        raises(Fail);
    ObjSeq all_instances(in string repository_id)
        raises(Fail);
    ObjSeq all_replica(in string repository_id,
                       in string instance_name)
        raises(Fail);
    DescSeq all_instances_descs(in string repository_id)
        raises(Fail);
    DescSeq all_replica_descs(in string repository_id,
                              in string instance_name)
        raises(Fail);
    void reg_trigger(in TriggerDesc desc,
                     in TriggerHandler handler)
        raises(Fail);
    void unreg_trigger(in TriggerDesc desc,
                       in TriggerHandler handler)
        raises(Fail);
};