With userApplication startup, the takeover virtual interface (sha0:65) over operating node will be activated, enabling communication using the takeover virtual IP address.
When operating, Fast switching mode uses the redundant line control function to communicate with the remote system.
Note that the virtual interface (such as sha0) is activated just after the redundant line control function starts up.
Once it becomes active, regardless of stopping or restarting userApplication, it remains to be active until the system stops.
Figure 5.4 Startup behavior of Fast switching mode shows behavior of Fast switching mode after starting up
Figure 5.4 Startup behavior of Fast switching mode
During normal operation, the system communicates with the remote system using Redundant Line Control Function on the operating node.
If a failure (panic, hang-up, or line failure) occurs on the operating node, Redundant Line Control Function switches the resources to the standby node. Then, applications make reconnection to take over the communication from the operating node.
Figure 5.5 Switching behavior of Fast switching mode indicates switching behavior of Fast switching mode.
In the following figure, the takeover IP address (IPa) is allocated to the takeover virtual interface (sha0:65) for operating node A. Then it activates the takeover virtual interface. When switching the interface due to failures in the transfer path, the takeover virtual interface (sha0:65) for operating node A becomes inactive. Then in standby node B, the takeover virtual interface (sha0:65), which has allocated the takeover IP address (IPa) becomes active. Note that the virtual interface (sha0) in node A remains unchanged.
Figure 5.5 Switching behavior of Fast switching mode
The following shows a procedure of performing fail-back after failure recovery if node switching occurs.
1) Make recovery for a node on which a failure has occurred.
If switching has occurred due to panic or hang-up, reboot the node that has panicked or hanged up.
If switching has occurred due to a line failure, restore the line to a normal status (perform necessary work such as reconnecting a cable, powering on a HUB again, and replacing a faulty HUB).
2) Restore the original operation status.
Restore the original operation status by performing fail-back operation for userApplication from "Cluster Admin" in Web-Based Admin View.
Figure 5.6 Stopping behavior of Fast switching mode illustrates stopping process of userApplication.
Figure 5.6 Stopping behavior of Fast switching mode
