Oracle Essentials [Electronic resources] : Oracle Database 10g, 3rd Edition نسخه متنی

11.7 Grid Computing

The
"g" in
Oracle Database
10g signifies Oracle's focus on
enabling grid computing with this database release.
Grids are simply pools of computers that provide
needed resources for applications on an as-needed basis. The goal is
to provide computing resources that transparently scale to the user
community, much as an electrical utility company can deliver power to
meet peak demand by accessing energy from other power
providers' plants via a power grid. Computing grids
enable this dynamic provisioning of CPU and data resources (shown in
Figure 11-6). Oracle Database
10g with RAC form the foundation for the
provisioning of these resources.

Figure 11-6. Sample grid configuration, including computer blades and cluster

Oracle
Database 10g adds several important features
that enable the delivery of resources when needed via a grid:

Dynamic Service Provisioning

This feature automatically allocates and reallocates server resources
based on configuration and failover rules. Service requests are
automatically routed to the server with the least load. If a server
fails, the surviving services are automatically reallocated to the
available servers.

Web services

Web services are also an inherent part of the grid landscape, because
applications running on the grid want to use the same type of
transparent access to components (or services) that users have to
applications. New database web services provide support for queries,
messaging, and DML, can access Java and PL/SQL, and can provide full
XML support.

Rolling upgrades

Oracle Database 10g facilitates the management
of large numbers of nodes through rolling upgrades. A rolling upgrade
allows you to bring down some of the nodes in the grid, upgrade their
software, and then bring them back online as part of the grid. You
can then repeat this procedure with the other nodes. The end result
is that you can achieve a complete upgrade of your Oracle database
software without having to bring down the database.

Automatic Storage Management

The ASM system also enables management of large numbers of nodes by
implementing automatic data rebalancing across disks, as well as easy
addition of new disks to the overall pool of storage.

Enterprise Manager

Enterprise Manager 10g is designed to manage a grid infrastructure
from a central location, including RAC databases, storage, Oracle
Application Servers, and network services.