Users Guide

Verifying Clustered Installations | Clustering
OMNM 6.5.3 Installation Guide 129
You can also observe medserver status within the Mediation panel in Control Panel. When a
mediation server goes down you should see its severity turns to Critical.
Mediation Clustering
You can configure mediation servers which can fail over SNMP/CLI requests by configuring
mediation servers as redundant peers during installation, or with the
com.dorado.mediation.listener.use.high.availability=true/false property
in
installed.properties . This configures failover for data collection for performance data,
traffic flow, traps, syslog and informs.
NOTE:
Remember: You must configure monitored devices to forward traps to both mediation servers.
The standby server does not forward data unless the active server becomes unavailable. The
mediation server that starts first is OpenManage Network Manager’s
active server. When you shut
down the active server, or it stops responding, OpenManage Network Manager promotes the
standby server to
active . If a server process shuts down, it is no longer considered active . However, if
the network connection is lost to the active server, but the server process continues to run, it is still
considered
active , and once the network connection is restored, OpenManage Network Manager
considers both servers temporarily
active .
Both servers can forward data to application server, and application server eliminates duplicates.
When OpenManage Network Manager detects that the connection to the disconnected mediation
server has been restored, and that both servers are now
active , the server with the lowest IP address
remains
active , and the other server becomes standby . The detection process takes approximately
two minutes and then an additional period of seconds for the sorting of
active / standby servers to
occur. The standby should hold any data which had not been processed during switchover and that
backlog should be processed when it becomes active.
See
Independent and Clustered Mediation Agents on page 130 for the alternative when
mediation agents have to communicate with clustered application servers.
NOTE:
Best practice for changing properties in the following steps assume that you override the mentioned
properties with properties pasted in
owareapps/installprops/lib/
installed.properties
, rather altered than in the mentioned properties files.