TS/MP 2.5 Management Programming Manual

Server Objects
When developing a management application that defines and manages server classes, consider:
• To add a full server class definition, issue an ADD SC command followed by ADD commands
for each of the optional object types desired, namely SCPROCESS, SCASSIGN, SCPARAM,
and SCSTARTUP.
• When you delete an SC object, all associated objects for that SC are also deleted.
• An associative server is a process within a server class. An associative server may be started
outside of the Pathway subsystem by a process other than the PATHMON process that controls
the server class but is used by that PATHMON process. Associative servers are configured
with the ZASSOCIATIVE field in ZPWY-DDL-DEF-SCPROCESS set to ZPWY-VAL-ON.
The PATHMON process can change the state of an associative server from STOPPED to
RUNNING without actually creating a new server. If the PATHMON process attempts to create
an associative server and discovers that the server already exists, the PATHMON process
changes the server state to RUNNING and uses the existing server (instead of reporting an
error).
Similarly, the PATHMON process can change the state of an associative server from RUNNING
to STOPPED even though the process might still be running. This can occur when:
◦ A STOP SC command is issued. The PATHMON process only waits until all links to the
associative server known to the PATHMON are returned by the link manager (such as
the ACS subsystem process).
or
◦ The last link to the associative server known to the PATHMON process is returned by a
link manager (that is, ACS subsystem process), but the server was not started by the
PATHMON process.
In both of these cases, the PATHMON process changes the state to STOPPED without waiting
for the server to terminate.
When the last link known to the PATHMON process is returned by a link manager and the
associative server is started by the PATHMON process, the PATHMON process leaves the
server state as RUNNING (instead of changing it to PENDING). A RUNNING state allows
the PATHMON process to continue to allocate links to the server while other requesters continue
to use the server. However, an interval occurs when the PATHMON process can grant a link
to an associative server that is stopping itself.
Although the STOPPED marker allows you to use the ALTER SC command to specify changes
for configuration attributes, the changes you specify are not effective until the associative
server is actually stopped and restarted from this Pathway subsystem.
Changes to these do not take effect until the PATHMON process receives a START SC
command for an associative server that has actually stopped:
◦ ASSIGN message specified with the ADD SCASSIGN or ALTER SCASSIGN command
◦ DEFINE message specified with the ADD SCDEFINE or ALTER SCDEFINE command
◦ PARAM message specified with the ADD SCPARAM or ALTER SCPARAM commands
◦ Startup message specified with the ADD SCSTARTUP or ALTER SCSTARTUP commands
◦ The ZDEFAULTVOLUME, ZGUARDIANLIB, ZHOMETERM, ZIN, ZOUT, ZPRIORITY, and
ZPROGRAM fields in ZPWY-DDL-DEF-SC
Programming Considerations for Specific Object Types 47