TS/MP 2.5 System Management Manual

For a complete description of all the SET PATHWAY attributes, see “SET PATHWAY Command”
(page 159).
Specifying limits always involves some guessing, with penalties if you estimate wrong. Begin with
a thorough understanding of your business application environment. Then choose your global
parameters very carefully. Once you start your PATHMON environment, you cannot alter these
limits without shutting the environment down for complete reconfiguration.
HP recommends that you always allow some space for growth. For example, if you are not certain
whether you might need an extra server class, leave room for one or two of these objects. Providing
for a few more objects than you initially need can save you much unnecessary work later. If you
specify unreasonably large limits, however, you cause the PATHMON process to allocate unused
virtual storage and the corresponding swap-file space.
For more information about limits and default values for your PATHMON environment, see
“Configuration Limits and Defaults” (page 318). Note that identifying a truly optimum configuration
for your PATHMON environment can require a significant degree of calculation and tuning that
is beyond the scope of this manual. For additional help, contact your HP representative for details
about performance classes offered and for a description of services available from service provider.
Specifying Node Independence
You can avoid hard-coding node names for many Guardian file names and other variable names
in your PATHMON environment by setting the NODEINDEPENDENT attribute of the SET PATHWAY
command to ON. When NODEINDEPENDENT is ON, unspecified node names for processes and
devices default to the node where the PATHMON process is running after cool start.
Specifying node-independent names for processes and devices facilitates switching your PATHMON
application to another node, either in the event of failure or as part of a planned migration (for
example, in a configuration that uses Nomadic Disk technology). When the PATHMON process
is cool started on a different node, the unspecified node names resolve to that node, thereby
migrating the associated objects.
This command establishes node independence for objects in your PATHMON configuration, unless
a node name is explicitly specified for a given object:
= SET PATHWAY NODEINDEPENDENT ON
When the NODEINDEPENDENT attribute is ON, any unspecified node names in the Guardian
file names defined for processes or devices are automatically set to \*, a generic node name
designating the node where the PATHMON process is currently running. NonStop TS/MP and
Pathway/iTS both support objects that can be configured as node-independent—SERVER objects,
for example, as well as TERM and PROGRAM objects and TCPs. For the complete syntax and a
list of object attributes containing Guardian file names, see the “SET PATHWAY Command”
(page 159).
When to Set Node Independence
If you choose to use the NODEINDEPENDENT attribute, specify it early in your PATHMON
configuration session to ensure that it applies to other global parameters, for example, the
PATHMON dump file. Once set, the attribute applies to all subsequent SET commands. The setting
has no effect on previously specified SET PATHWAY commands.
Node Independence and the CMDVOL Command
Setting the Pathway NODEINDEPENDENT attribute to ON overrides and disables the node field
of the CMDVOL command. See “CMDVOL Command” (page 138).
Some Names Are Always Node-Independent
Note that some object names are node-independent regardless of whether you use the
NODEINDEPENDENT attribute or not. These include the names of log files in which the PATHMON
process records errors and object status changes. If you leave the node portion of a log file name
54 Configuring Objects in a PATHMON Environment