TS/MP 2.5 System Management Manual

Configuring Static and Dynamic Server Processes
There are two types of server processes: static and dynamic. A static server is a server process
that the PATHMON process creates when the START SERVER command is issued. A dynamic
server is a server process that the PATHMON process creates after a link manager has waited for
a specific time period for a static server to become available. The time period is determined by
the CREATEDELAY attribute for the server class. This type of server is not dependent on the START
SERVER command.
A dynamic server process runs as long as a link manager ACS subsystem processes, communicates
with it. Unused links to dynamic servers are returned to the PATHMON process by the link manager.
The PATHMON process deletes unused links based on the time limit defined by the DELETEDELAY
attribute for the server class. If high system performance is required, it is recommended that you
not use dynamic server processes because they incur a startup penalty as part of the transaction
path.
You determine the total possible number of static and dynamic server processes in your system
when you specify the SET SERVER command, using the NUMSTATIC and MAXSERVERS attributes.
Defining Attributes for Guardian and OSS Servers
For any server class, the PATHMON process requires you to specify the PROGRAM attribute. This
attribute indicates the name of the file that contains the object program that the server processes
run. (An important difference between Guardian and OSS servers is that whereas you can START
Guardian servers on remote nodes, you cannot START remote OSS servers. Thus, a Guardian
server PROGRAM attribute can include a remote node name, but an OSS server PROGRAM
attribute cannot.)
In addition, the PATHMON process allows you to specify various optional attributes for server
classes or to accept default values for them. Most of these attributes are common to both Guardian
and OSS servers. Among the optional attributes that apply to both Guardian and OSS servers are:
• PROCESSTYPE specifies whether the server process is a Guardian or an OSS server. The
default is Guardian. When you use the INFO SERVER command, this attribute is listed first
so you can quickly identify a server as a Guardian or an OSS server. All other attributes are
listed in alphabetic order.
• AUTORESTART specifies the number of times the PATHMON process attempts to restart a
server process within a fixed, 10-minute interval after an abnormal termination, such as a call
to the Guardian ABEND procedure. The default is 0. In such cases, the PATHMON process
does not attempt to restart a server process after an abnormal termination.
NOTE: The PATHMON process might restart a static server process any number of times if
no other server process is available to serve a current link request irrespective of AUTORESTART
attribute.
If the server process stops under normal circumstances, for example, in response to a STOP
command, the PATHMON process does not attempt to restart it.
• The CPUS attribute specifies the CPUs on which server processes of this server class will run.
You can specify either a list of paired (primary and backup) CPUs or a list of single CPUS.
If you specify single CPUs and a processor is down, the PATHMON process chooses the next
processor in the list.
When you specify a processor pair for a Guardian server, the PATHMON process creates
an extra parameter called BACKUPCPU to hold the number of the processor specified as a
backup. This parameter is passed to the server as part of the PARAM message. As it creates
the server processes, the PATHMON process uses the primary CPUs in the order specified. If
a processor is down, the PATHMON process uses the backup processor as an alternate
processor and passes the primary processor number as the backup processor parameter.
62 Configuring Objects in a PATHMON Environment