Sybase failover allows you to configure two version 12.0 or later Adaptive Servers as companions. If the primary companion fails, that server’s devices, databases, and connections can be taken over by the secondary companion.
You can configure a high availability system either asymmetrically or symmetrically.
An asymmetric configuration includes two Adaptive Servers, each physically located on a different machine, that are connected so that if one of the servers is brought down, the other assumes its workload. The secondary Adaptive Server acts as a “hot standby” and does not perform any work until failover occurs.A symmetric configuration also includes two Adaptive Servers running on separate machines. However, if failover occurs, either Adaptive Server can act as a primary or secondary companion for the other Adaptive Server. In this configuration, each Adaptive Server is fully functional with its own system devices, system databases, user databases, and user logins.In either setup, the two machines are configured for dual access, which makes the disks visible and accessible to both machines.You can enable failover in jConnect and connect a client application to an Adaptive Server configured for failover. If the primary server fails over to the secondary server, the client application also automatically switches to the second server and reestablishes network connections.
Refer to Using Sybase Failover in High Availability
Systems Manual for Adaptive Server for more detailed
information.
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