 |
need the functionality but have tight IT expenditure concerns.
ExpressCluster can be configured to get an Oracle instance up or down by starting or stopping the service in the cluster configuration. All Oracle data files are brought over together to the other node. Or it can simply perform the failover by easily "move" operation to perform the Oracle software upgrade. It's an ideal solution for planned or unplanned Oracle downtime.
ExpressCluster relies less on the hardware and software requirements. Others solutions like RAC require high performance hardware in order to reach the required SLA. With ExpressCluster, it supports most of Standard, Enterprise or Datacenter editions within the host environments.
The primary advantage of ExpressCluster is that the failover of the database and related applications to ensure no loss of data, needs no intervention by the DBA or Systems Administrator. At the time of this failover, there is no need for the DBA to locate and apply the latest redo information, as required for a Primary-Standby configuration.
With synchronous mirroring, everything up to the last commit is saved.
When failover occurs in the Virtual Identity or Virtual IP address defined for a service, new connections to the database are automatically routed to the correct node with no intervention whatsoever. The end users have no knowledge of the failover or downtime that had just happened.
Optionally, with the Database Agent Option implemented, a certain number of Listener restart attempts may be specified before a failover.
Oracle offers RAC, Advanced Replication or OPS (Oracle Parallel Server). Unlike the native Oracle HA or replication products, ExpressCluster does not need data or user segmentation as only one instance running at one time for a service group. Besides, the configuration for the cluster group is straight-forward in ExpressCluster.
Finally, ExpressCluster works in the heterogeneous environment with scalability. As companies expand, the additional databases can be added to the HA cluster with small efforts to add the new Oracle instances. The same unified management web console can be used to manage a new cluster group to house all resources associated with the new database in LAN, WAN or SAN configurations.
|
