In order to be useful to users, the Heartbeat daemon needs to be combined with a cluster resource manager (CRM) which has the task of starting and stopping the services (IP addresses, web servers, etc) that cluster will make highly available.
Heartbeat originally came with a primitive resource manager, however this is only capable of managing 2 nodes and could not detect resource-level failures.
A new resource manager which addressed these limitations and more was written for Heartbeat 2.0.0.
Information about Pacemaker is available from the project web site.
There are various user interfaces to Pacemaker:
- the crm shell by Dejan Muhamedagic, a powerful commandline/curses interface hiding the xml configuration details, including online help and tab completion
- the high availability web konsole by Tim Serong, an AJAX web frontent in its very early stages
- the heartbeat gui by Yan Gao, basically an advanced xml editor plus action buttons and status display
- the LCMC by Rasto Levrinc, (which started out as "DRBD-MC" when he was still employed by LINBIT), a Java based platform independent management console , featuring various wizards and even integrating a VNC Viewer for Virtual Machines controlled by Pacemaker.