HP UX SNAplus2 Figure D-5, SNAplus2 on Primary and Backup Servers

Using SNAplus2 in a High Availability Environment

SNAplus2 High Availability Features

At this point, the backup server has completely taken over the primary server and is providing the HALU01...HALU09 LUs for the production applications. The less important development LUs are no longer available. The key point is that the production applications do not need to change when this switch takes place. The location of where the software components are started changes, not the underlying SNAplus2 configuration. SNAplus2 will automatically route data to and from the production applications through the backup server.

Figure D-5	SNAplus2 on Primary and Backup Servers
	Client	Client	Client	Client
				LAN
	Primary HP-UX Server hp_pri		Backup HP-UX Server hp_back
			Development Configuration
	Temporarily Out of Service		Node................	DEVNODE
			LS....................	DEVLS
			Port..................	DEVPORT
			LUs..................	...DEVUO1 DEVLU09

Token Ring

3xxx

Communications

Controller

IBM

Host

This feature makes it easy to provide backup capability when the primary server needs to be taken offline. Later sections describe how the MC/ ServiceGuard product can automate the switch from a primary to a backup server even when unexpected failures occur.

364 Appendix D