Users Guide

Understanding Installation Types | Preparing for Installation
22 OMNM 6.5.3 Installation Guide
the primary and secondary Application server, so that the failover is transparent to the clients and
Mediation servers. Servers also use configurable heartbeats to monitor each others status. If the
primary fails, the secondary takes over and generates an event/alarm. Clients and Mediation servers
identify Applications server by partition name. This is the same for the primary and secondary
Application server, so that the failover is transparent to the clients and Mediation servers.
If you want to extend this to the database, Oracle Real Application Clusters (RAC) handle
database replication, synchronization and failover. Application servers identify Oracle by Service
Name, which is the same for all Oracle hosts, so failover between Oracle hosts is transparent to this
application.
You can also have a form of Db HA at the application level with transaction management. For
example, Db HA installations support the following:
• Application server clustering
• Mediation server load balancing (with the Application server round robin process)
• Mediation server failover
• Database redundancy (must have Oracle Parallel Server, Oracle’s Real Application Cluster
[RAC], Mysql replication or MHA or equivalent database).
Additional details are discussed in:
•
Clustered Mediation Servers
• Web Portal Installation
• Application Server Installation
• Mediation Server Subnets
• Routing Behavior
• Compatibility with Previous Versions
• Configuration Options
Clustered Mediation Servers
For reliability, paired Mediation servers can fail over when they transmit SNMP traps and/or
Network Element-initiated Syslog Messaging to Application servers. For failover to work, you must
enable multicast between the cluster’s Mediation servers.
Each server in the cluster has a primary and a secondary role, and uses keep-alives heartbeats to
verify the other Mediation server's operational state. Based on the operational state, only one
Mediation server (the primary) forwards messages to the Application servers for processing.
Refer to the
OpenManage Network Manager User Guide for more specifics on configuring
mediation clustering.
The simplest
high availability (HA) installation is to configure your system with the full
application on two machines. In this scenario, the Application servers are clustered and Mediation
servers are configured for redundancy. Oracle RAC or replication produces database redundancy.