VMware vCenter Server is VMware’s management tool for ESX/vSphere hosts and VM’s and it’s configuration and health status. This tool is becoming important more and more: DRS, VMotion, HA and other management tasks rely on this server.
The importance is becoming higher when it is managing a VMware View environment. vCenter is controlling the provisioning and power settings for example. Without vCenter, no virtual desktops are provisioned, deleted, shut down and started for example. Running desktops with users working on them will continue to work though.
vCenter Heartbeat is a product which helps to protect vCenter Server. VMware OEM’s this product from the Neverfail Group. It protects the following;
-vCenter Server/database application failure, network failure, host failure.
vCenter Heartbeat is a mechanism which is based on a “shared nothing” pair of servers. This could be a pair of 2 servers with vCenter+database locally or 2x pairs of server where vCenter and the database are separated.
The pair can be a physical-physical/Physical-virtual/virtual-virtual pair of servers. In case of a virtual-virtual, you can simply clone the primary server to get your secondary.
After the setup of the pair(s) of servers, data from the primary server is replicated asynchronously to the secondary so (both) pair(s) contain the same data. Also, vCenter and the database services are being monitored for performance and other issues that may impact availability. A separate network, “heartbeat channel”, is used to maintain a heartbeat between the 2 servers allowing the secondary server to detect a failure.
On the secondary site, the vCenter/database are in a stopped state and hidden from the network through an IP packet filter. This because the pairs are identical (name and IP wise).
In a case of a host, application or service failure, a failover will happen and the secondary server will become the primary automatically. After ‘repairing” the failed server you can manually failover again so the “now secondary” will become the primary again.
vCenter Heartbeat is based on Neverfail technology but is dedicated to VMware. It is a “hidden” product but worth looking at. A lot of good information can be found;
Product page; http://www.vmware.com/products/vcenter-server-heartbeat/
Documentation page; http://www.vmware.com/support/pubs/heartbeat_pubs.html
Community page; http://communities.vmware.com/community/vmtn/mgmt/heartbeat