Novell Documentation: iManager 2.5 - High Availability: Running iManager in a Clustered Environment

9.5 High Availability: Running iManager in a Clustered Environment

Although iManager is a session-based tool that ships without any failover feature, you can run it in a clustered environment.

Install and configure iManager on the nodes in the cluster where the virtual IP is moved to (i.e., an Active/Active cluster). If the node running iManager were to fail, Novell Cluster Services (NCS) detects the node failure and will move (re-load) the virtual IP address on another node in the cluster.
Using the Generic_IP_Service template that ships with NCS, create a new cluster resource called iManager. This cluster resource uses a virtual IP address that moves between nodes in the cluster. When creating a new cluster resource, the wizard steps you through the creation of a load script and an unload script.
Verify the load and unload scripts.

The load script should contain only the following lines (any other lines should be commented out):
```
. /opt/novell/ncs/lib/ncsfuncs
```
```
exit_on_error add_secondary_ipaddress xxx.xxx.xxx.xxx
```
```
exit 0
```
The unload script should contain only the following lines (any other lines should be commented out):
```
. /opt/novell/ncs/lib/ncsfuncs
```
```
ignore_error del_secondary_ipaddress xxx.xxx.xxx.xxx
```
```
exit 0
```
Point your Web browser to: http://web_server/nps/iManager.html (web_server is the IP address used in the iManager cluster resource).

iManager services are now highly available; however, any live sessions are not failed over. If a service fails in the middle of user operations, users must re-authenticate and re-start whatever operations were interrupted.

Because iManager/tomcat/apache is already running (Active/Active) on the other nodes, there is no load time of these applications in the event that NCS has to migrate (move) the virtual IP to another node.

There is little benefit in using an Active/Passive cluster as it requires much more configuration and makes you wait the entire load time for each failover. If you really want iManager configured as an Active/Passive clustered resource, you must create a cluster resource that loads and unloads iManager and its dependencies (i.e., Apache and Tomcat). This identical configuration of iManager then needs to be done on all nodes where you want iManager highly available.