Pathway/XM System Management Manual

Managing a Pathway/XM Environment
Compaq NonStop™ Pathway/XM System Management Manual—426761-001
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Pathsend Requesters
Pathsend Requesters
Pathsend requesters are self-contained, user-written Guardian processes that use
Pathsend procedure calls, rather than SCREEN COBOL programs and the TCP, to
communicate with server classes. Workstation clients that use the Compaq NonStop™
Remote Server Call/MP (RSC/MP), for example, communicate with Pathway servers
indirectly by means of Pathsend requesters created by RSC on behalf of the clients.
LINKMON Processes
Each processor (CPU) has one LINKMON process, which starts when the CPU starts.
The LINKMON process is shared by all Pathsend requesters running in a given CPU.
LINKMON processes facilitate communication between Pathsend requesters and their
servers, much as TCP and PATHMON processes provide those functions for SCREEN
COBOL requesters.
Although LINKMON processes are visible in the Pathway/XM environment, they are
not controlled or managed by PXMCFG or PXMCOM. However, you can obtain status
information about LINKMON processes through PXMCOM.
Communication With the Well-Known Named PATHMON Process
Requests from Pathsend processes are always directed to the well-known named
PATHMON process, and are serviced by the server processes controlled by that
PATHMON process.
A LINKMON process communicates with the well-known named PATHMON process
as long as it has a link to a server process running under that PATHMON process.
When a LINKMON process no longer has any links to any server process under the
PATHMON process, it terminates its connection to the well-known named PATHMON
process.
Execution
LINKMON processes support access to server classes by requester programs written in
TAL, C, COBOL85, or Pascal. They provide access support by helping to execute calls
to the Pathsend procedures.
Each CPU contains one LINKMON process, which is responsible for all Pathsend
requesters executing in its CPU. A LINKMON process acquires links from the
PATHMON process that controls the server class. The LINKMON process then shares
its links among the Pathsend requesters executing in its CPU.
LINKMON processes are visible within a Pathway/XM environment but cannot be
configured or controlled as directly as other Pathway/XM processes. Some PXMCFG
command parameters affect LINKMON processes, and you can use PXMCOM
commands to perform various LINKMON-related functions.
Note. Context-sensitive Pathsend requesters and servers cannot be used with distributed
server classes. You must configure context-sensitive servers as either direct or replicated
server classes.