IBM AS/400e, Руководство пользователя

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Operating System/400, 5769-SS1
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Operating System/400, 5769-SS1
Cluster Resource Services consists of an open set of APIs that provide cluster facilities.
AS/400 application providers and customers use the APIs to enhance their application
availability and to create, configure, and administer the cluster. Systems are defined into the
cluster as cluster nodes. Communication interface addresses are defined to form the cluster
node-to-node interconnection links. Resilient resources (objects replicated to one or more
nodes) are associated with a Cluster Resource Group (CRG) so they can be managed as a
single unit.
Two types of CRGs are supported: one for data resilience and one for application resilience.
Data CRGs provide the control to switch the point of access for a set of data to a backup node
that maintains an exact replica of that data. Application CRGs control switching an IP address
representing the application server to a backup node and restart the application in the event
of a primary node failure.
Cluster Resource Services includes integrated facilities such as heartbeat monitoring,
reliable message delivery, switch-over administration, and distributed activities. The services
are built on a robust cluster topology and messaging functions that keep track of each node in
the cluster and ensure that all nodes have consistent information about the state of cluster
resources. Heartbeat monitoring ensures that each node is active. When the heartbeat for a
node fails, the condition is reported so that the cluster can automatically failover to the
resilient resources on the backup node. System Services for high availability solutions are
enhanced with real-time recording of IFS stream file changes into journals. Data resiliency
applications can use this function to provide enhanced support for this class of objects.
IBM has worked closely with the high availability business partners to provide easy-to-use
cluster management applications. DataMirror, Lakeview Technology, and Vision Solutions
intend to announce their own initiatives for products that take advantage of the cluster
resource services and integrated file system stream file support.
AS/400 clusters support up to 128 nodes, using any combination of the existing OptiConnect
WAN and LAN connectivity options to build the cluster:
• OptiConnect hardware, fully supported as an orderable system feature, is an attractive
connectivity method for high-end and mid-range models.
• ATM provides a high-performance connection to remote systems in the cluster.
• Ethernet and Token-Ring LANs are ideal for connecting low-end AS/400 models into
the cluster.
All systems are managed from a single workstation containing the high-availability business
partner cluster management application.
OS/400 V4R4 must be installed on each node in the cluster.