Users Guide

Cluster Constraints | Clustering
108 OMNM 6.5.3 Installation Guide
• Paired, redundant mediation servers to handle traffic between OpenManage Network
Manager and managed devices.
Cluster Constraints
This section describes the constraints within which a cluster configuration must work.
• All servers in a cluster must be on the same local area network (LAN), be reachable for IP v4
multicast, and must have unique names. Clustering is
not designed for servers in different
time zones (however, you can have mediation agents send data from distant locations). For an
exception to the multicast requirement, and for managing servers and clients outside
firewalls, see
Disabling Multicast on page 111. You will need to use unicast instead of
multicast when cluster member nodes are on different IP subnet.
To ensure that application server nodes do not miss server-to-server heartbeats that may
erroneously initiate fail-over processes, you must connect clustered application servers via a
LAN with maximum latency of 100ms. That said, you can put clustered server nodes several
miles/kilometers apart, as long as the connection does not exceed the maximum latency
(using Fibre ethernet, for example). WAN connectivity is not recommended.
NOTE:
Although high-speed interconnects may be able to increase the distance of application server nodes to
over 5km, the High-Availability solution is not designed for disaster recovery situations. Dorado Software
recommends the use of a separate OpenManage Network Manager deployment located at the disaster
recovery location to be used as a cold standby system. The database of the primary system should be