Ko te Pacemaker he punaha whakahaere rauemi tuwhera puna nui e whakamahia ana i runga i nga roopu rorohiko mai i te tau 2004. Tae noa ki te tau 2007, he wahanga o te kaupapa Linux-HA, katahi ka wehea hei kaupapa ake. Ka whakatinanahia e ia etahi API mo te whakahaere rauemi, engari ko tana API pai mo tenei kaupapa ko te Open Cluster Framework API kaihoko rauemi.