SQL/MP Installation and Management Guide

Managing a Distributed Database
HP NonStop SQL/MP Installation and Management Guide—523353-004
12-15
Changing Network Environments
In the preceding example, the SYS1 specifies the system for which you are controlling
processor usage. If you do not include a system name, the DEFINE applies to the
current system.
This example limits the processor usage on \MYSYS to processors 0 and 1:
>> ADD DEFINE =_SQL_CMP_CPUS_MYSYS, CLASS MAP, FILE XC;
This example limits the processor usage on \DEV1 to processors 2 and 3:
>> ADD DEFINE =_SQL_CMP_CPUS_DEV1, CLASS MAP, FILE X3;
This example limits the processor usage on \PROD1 to processors 0, 2, 4, 6, 8, 10, 12,
and 14:
>> ADD DEFINE =_SQL_CMP_CPUS_PROD1, CLASS MAP, FILE XAAAA;
Changing Network Environments
Network environments are often subject to change. Nodes can be added or removed,
system configurations at each node can change, the operating system can be updated
independently at each node, communication line speeds or types can change, and the
needs of the node with respect to the database or application can change.
Many of these changes do not affect the SQL database or environment and need not
concern you if you are a system manager. Certain changes, however, can cause
problems or affect the SQL environment and must be anticipated.
Generally, these situations need to be considered on a case-by-case basis:
•
A new node is added to the network. This addition does not affect the existing
database scheme. To access this node and incorporate it into the overall
environment, however, network passwords and security must be added to all other
nodes. After SQL is initialized on this node, SQL objects can be placed on the new
node.
•
An existing node is permanently removed from the network. All SQL objects that
refer to this node and all distributed SQL objects using this node must be purged
before the node is removed. If objects referring to this node are left in the
environment, these objects will receive errors from SQL on the remaining nodes.
•
A node must be renamed or given a new node number. This procedure can be
complex because the objects throughout the network that refer to an object,
partition, view, or index on this node have the node name and number embedded
in the file labels and referred to in the catalogs. For more information, see
Renaming or Renumbering a Node on page 9-32.
•
The operating system at a node is updated. Usually nodes run compatible but
different operating systems. Consult the current software release documents for
compatibility issues between operating system releases.
•
Communication to a node is lost. Situations can occur where nodes become
unavailable for various reasons. If at all possible, network transactions should be