A disaster is a situation in which critical components in the SAP environment become unavailable so that service cannot be resumed in a short period (less than a day as a general rule). A typical situation would be destruction of the hardware due to fire. The critical SAP system components are the database and the SAP application host instance that runs the enqueue and message services.
You consider the following steps to protect your installation:
· To protect SAP application host running enqueue and message services
This can be achieved by having a standby system available (at a remote site) that can be started up in the event of a disaster. If a standby system – which could also be another application server that has been reconfigured – is started to provide the critical SAP services, all other application servers have to be restarted.
· To protect the database
The entire database can be replicated but you have to use a method provided by the various database vendors. This approach is known as “Hot Site Backup” or “Standby Database.” The products mentioned below follow the concept of “replication transparency”. This means that the functionality to achieve replication is built into the database service instead of having to be coded by the client applications.