The new DB2® pureScale® Feature resource
model represents cluster caching facilities and the shared cluster
file system.
The DB2 pureScale Feature resource
model differs from the resource model used in previous DB2 Versions.
The new resource model implemented
with DB2 pureScale Feature is necessary to represent
cluster caching facilities (CFs) and the shared clustered file system.
In a DB2 pureScale shared data instance, one CF
fulfills the primary role, which contains the currently active data
for the shared data instance. The second CF maintains a copy of pertinent
information for immediate recovery of the primary role.
The
new resource model allows IBM® Tivoli® System Automation for
Multiplatforms (Tivoli SA
MP) to appropriately automate the movement of the primary role in
case of failure of the primary CF node.
DB2 cluster services includes three major components:
- Cluster manager: Tivoli SA
MP, which includes Reliable Scalable Cluster Technology (RSCT)
- Shared clustered file system: IBM General
Parallel File System (GPFS™)
- DB2 cluster administration: DB2 commands and administration
views for managing and monitoring the cluster
Figure 1. DB2 Cluster
services
DB2 cluster services provide essential infrastructure
for the shared data instance to be highly available and to provide
automatic failover and restart as soon as the instance has been created.
DB2 cluster elements are representations
of entities that are monitored and whose status changes are managed
by DB2 cluster services. There
are three types of DB2 cluster
elements:
- Hosts: A host can be a physical machine, LPAR (Logical Partition
of a physical machine), or a virtual machine.
- DB2 members: A DB2 member is the core processing engine and
normally resides on its home host. The home host of a DB2 member is the host name that was provided
as the member's location when the member was added to the DB2 shared data instance. A DB2 member has single home host. DB2 members can accept client connections
only when they are running on their home host.
- Cluster caching facilities (CFs): The cluster caching facility
(CF) is a software application managed by DB2 cluster services that provides internal operational
services for a DB2 shared data
instance. There is not necessarily a one-to-one mapping between DB2 cluster elements and the underlying
cluster manager resources and resource groups.
DB2 Version 10.1 for Linux, UNIX, and Windows
