Pathway/iTS System Management Manual (G06.24+)

Maintaining Pathway/iTS Objects
HP NonStop Pathway/iTS System Management Manual—426748-002
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Managing Links
For more information about SPI processes and event messages for the TS/MP and
Pathway/iTS products, see the TS/MP Management Programming Manual and the
Pathway/iTS Management Programming Manual.
Managing Links
A link is a connection between a link manager, such as a TCP, and a specific server
process. The link is used to send a request to, and receive a reply from, a server.
A TCP shares links among its multiple SCREEN COBOL requesters. Only one
SCREEN COBOL program at a time can use a link (by performing a SEND). TCPs
initiate link requests to Pathway servers.
A TCP attempts to use one of its existing links to satisfy a send request. If no such link
is available, then the TCP process does one of the following:
•
If the TCP can get a static link, it asks for a link immediately.
•
If the TCP cannot get a static link, and no static links become available in the
period of time specified in the CREATEDELAY parameter, then the TCP asks for a
dynamic link.
A link is managed and owned by the PATHMON process that controls the server
process. To perform link management, the PATHMON process maintains status
information for TCP, TERM, and SERVER objects.
By understanding how the PATHMON process manages links and what causes
dissolution of links, you can take steps to improve the performance of your system.
Steps you can take to improve link performance are described in the TS/MP System
Management Manual. Information on deletion of links appears in this subsection.
Understanding the Causes of Link Dissolution
A PATHMON process, LINKMON process, server process (indirectly), or TCP can
delete a link. To learn about deletion of links by PATHMON, LINKMON, or server
processes, see the TS/MP System Management Manual.
Note. The Pathway environment provides two types of link managers: TCPs and LINKMON
processes. TCPs manage links to server processes from SCREEN COBOL requester threads.
LINKMON processes manage links to server processes from Pathsend processes and from
clients and requesters running under related products such as the HP NonStop Remote Server
Call/MP (RSC/MP) software and the HP NonStop TUXEDO system. For more information
about LINKMON processes, see the TS/MP System Management Manual.