Alteon Application Switch Operating System Application Guide
High Availability
572
Document
ID:
RDWR-ALOS-V2900_AG1302
What Happens When Alteon Fails
Assume that the user performing an e-commerce transaction has selected a number of items and
placed them in the shopping cart. The user has already established a persistent session on the top
server, as shown in
Figure 88 - Stateful Failover Example when the Master Alteon Fails, page 572
The user then clicks Submit to purchase the items. At this time, the active Alteon fails. With stateful
failover, the following sequence of events occurs:
1. The backup becomes active.
2. The incoming request is redirected to the backup.
3. When the user clicks Submit again, the request is forwarded to the correct server.
Even though the master has failed, the stateful failover feature prevents the client from having to
re-establish a secure session. The server that stores the secure session now returns a response to
the client via the backup.
Figure 88: Stateful Failover Example when the Master Alteon Fails
To configure stateful failover
This procedure is based on
Figure 88 - Stateful Failover Example when the Master Alteon Fails, page
1. On the master:
a. Enable stateful failover.
b. Set the update interval. The default is 30.
>> Main # /cfg/slb/sync/state ena
>> Main # /cfg/slb/sync/update 10
