HP ProLiant 4500 Compaq ProLiant Cluster HA/F100 and HA/F200 Administrator Gui - Page 37

Active/Standby Configuration

Page 37 highlights

2-6 Compaq ProLiant Clusters HA/F100 and HA/F200 Administrator Guide If the node running the order entry database encounters a failure, the database fails over to its secondary node. The order entry clients experience a slight disruption of service while the database resources are failed over, the database transaction log is rolled back, and the information in the database is validated. When the database validation is complete, the order entry application is brought online on the file and print server and the clients can reconnect to it. While the database validation is occurring, file and print activities continue without disruption. If the file and print server encounters a failure, those services are not failed over to the order entry server. File and print services are offline until the problem is resolved and the node is brought back online. Active/Standby Configuration The primary difference between an active/active configuration and an active/standby configuration is the number of servers actively processing data. In active/standby, only one server is processing data (active) while the other (the standby server) is in an idle state. The standby server must be logged in to the Windows NT domain and MSCS must be up and running. However, no applications are running. The standby server's only purpose is to take over failed clustered applications from its partner. The standby server is not a preferred node for any clustered applications and, therefore, does not fail-over any applications to its partner server. Because the standby server does not process data until it accepts failed over applications, the limited use of the server may not justify the cost of the server. However, the cost of standby servers is justified when performance and availability are paramount to a business' operations. The standby server should be designed to run all of the clustered applications with little or no performance degradation. Since the standby server is not running any applications while the cluster is in a normal operating state, a failed-over clustered application will likely execute with the same speed and response time as if it were executing on the primary server.

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2-6
Compaq ProLiant Clusters HA/F100 and HA/F200 Administrator Guide
If the node running the order entry database encounters a failure, the database
fails over to its secondary node. The order entry clients experience a slight
disruption of service while the database resources are failed over, the database
transaction log is rolled back, and the information in the database is validated.
When the database validation is complete, the order entry application is
brought online on the file and print server and the clients can reconnect to it.
While the database validation is occurring, file and print activities continue
without disruption.
If the file and print server encounters a failure, those services are not failed
over to the order entry server. File and print services are offline until the
problem is resolved and the node is brought back online.
Active/Standby Configuration
The primary difference between an active/active configuration and an
active/standby configuration is the number of servers actively processing data.
In active/standby, only one server is processing data (active) while the other
(the standby server) is in an idle state.
The standby server must be logged in to the Windows NT domain and MSCS
must be up and running. However, no applications are running. The standby
server’s only purpose is to take over failed clustered applications from its
partner. The standby server is not a preferred node for any clustered
applications and, therefore, does not fail-over any applications to its partner
server.
Because the standby server does not process data until it accepts failed over
applications, the limited use of the server may not justify the cost of the server.
However, the cost of standby servers is justified when performance and
availability are paramount to a business’ operations.
The standby server should be designed to run all of the clustered applications
with little or no performance degradation. Since the standby server is not
running any applications while the cluster is in a normal operating state, a
failed-over clustered application will likely execute with the same speed and
response time as if it were executing on the primary server.