Pathway/XM System Management Manual

Summary of Differences Between the Pathway/XM
Environment and the PATHMON Environment
Compaq NonStop™ Pathway/XM System Management Manual—426761-001
D-2
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Because of Pathway/XM’s automatic load-balancing features, some object attributes
have different meanings in the Pathway/XM environment. For example, in the
Pathway/XM environment the TCP attribute MAXINPUTMSGS specifies the
maximum number of unsolicited messages that can be queued per TERM object
rather than per TCP.
The following detailed differences also apply:
•
Pathway/XM balances requester and server workload automatically by assigning
processors (CPU numbers) to PATHMON processes, server classes, and TCPs.
Such assignments are made initially and when a CPU fails. Pathway/XM’s CPU
assignments are based on general system resource information you specify in the
NODE objects in your configuration. You cannot manually assign CPU numbers to
individual processes or terminal tasks.
•
The Pathway/XM environment provides automatic load balancing of terminal and
server processing. As a result, the system manager has less direct control over
PATHMON processes, TCPs, and server processes than in a PATHMON
environment. Some backward-compatible features—for example, direct and
replicated server classes—provide more direct control, but at the expense of
Pathway/XM load-balancing and online reconfiguration capabilities.
•
To configure a Pathway/XM environment for future migration to another set of
Compaq NonStop
TM
Himalaya systems, you use the SYSTEM and DEFAULT
attributes of the logical nodes (NODE objects) rather than the
NODEINDEPENDENT attribute of the SET PATHWAY statement.
•
You must specify the object type in all PXMCFG statements and PXMCOM
commands (except STATUS [SERVER] FREEZE).
•
In the Pathway/XM environment, TERM objects are automatically assigned to
particular TCPs as part of the requester load-balancing mechanism. Therefore,
PXMCOM commands directed to individual TCPs specify a terminal name rather
than a TCP name.
•
Pathway/XM provides three startup options: cold start, cool start, and warm start.
All of these options start the entire Pathway/XM environment.
•
In PXMCOM STATUS and STATS commands, you cannot specify the COUNT or
INTERVAL option for repeated collection of status and statistics information.
•
Open System Services (OSS) server processes are not supported in the Pathway/XM
environment.
•
Context-sensitive Pathsend servers cannot be configured as distributed server
classes in the Pathway/XM environment.
•
External TCPs are not generally needed, and are not recommended, in the
Pathway/XM environment.
•
Because configuration is performed offline using PXMCFG, the OBEYFORM
option is not supported in INFO commands. The PXMCFG statement file serves the
same purpose in the Pathway/XM environment as OBEYFORM output serves in the
PATHMON environment.