Operating System Level Failover (Without an Application Cluster)

The option of implementing failover in an application environment through the use of operating system level failover is a viable option for those not wishing to implement an application cluster.

The possible reasons for implementing this kind of failover include:
  • The designated backup platform may not always be available (possibly used for other purposes)
  • A particular failover technology is widely used and understood at a particular site
  • There are no facilities available to handle the front end redirection of network traffic
  • Application requires no specific special configuration for OS level failover
  • The primary purpose is disaster recovery at a remote site
There are also some reasons for avoiding OS level failover:
  • Dependence on platform-specific technology
  • Does not improve performance
  • Usually has a longer failover time (it generally requires a start of Sterling B2B Integrator, among other things)
  • There is a risk in most environments for the two systems to become slightly out of synch which can cause a failure during the takeover process.
  • It is not possible to reconfigure Sterling B2B Integrator without taking an outage
  • There are a variety of partial failure scenarios that have to be accounted for to ensure that the takeover is complete