TS/MP 2.5 System Management Manual

MAXSERVERS
The MAXSERVERS attribute specifies the maximum number of server processes in a server class
that can run at the same time. To determine maximum number of links available in a server class,
use the formula MAXSERVERS x MAXLINKS.
MAXLINKS
The MAXLINKS attribute specifies the maximum number of links to an individual server process
from all link managers, such as a ACS subsystem process. Consequently, while a server process
is processing a request, a number of requests up to the value of MAXLINKS minus 1 can queue at
the server.
For COBOL servers, make sure that the value you specify in the TABLE OCCURS clause of the
RECEIVE-CONTROL paragraph is greater than or equal to the number specified for MAXLINKS.
If the MAXLINKS value exceeds the value in the TABLE OCCURS clause, the PATHMON process
continues to grant links to the server process even after the server process has exceeded the link
limit. When a link manager tries to open such a server process, the server process rejects the link.
If you omit this attribute, the default is an unlimited number of links. It is strongly recommended
that you set a value for MAXLINKS.
LINKDEPTH
The LINKDEPTH attribute specifies the maximum number of links that any one link manager can
have to an individual server process in a server class. (Remember, too, that a link manager can
also have links to other server processes in the class.)
Unless a server process is able to process more than one request concurrently, LINKDEPTH must
be set to 1. (Typically, a COBOL server has a LINKDEPTH value of 1. A communication-based
server, such as an HLS server, can support a LINKDEPTH greater than 1.)
If LINKDEPTH is 1, each link manager can have only one link to each server process. Each request
to the PATHMON process for an additional link results in a link to a different server process. Each
link results in a single open of the server. The link manager makes the server open available for
use by multiple SCREEN COBOL programs or Pathsend processes and user applications,
respectively.
NOTE: Normally, only server programs that are coded as NOWAIT I/O must have a LINKDEPTH
value greater than 1. Setting the LINKDEPTH value greater than 1 for a WAITED server class can
lead to queuing at the server process and increased response time.
NUMSTATIC
The NUMSTATIC attribute specifies the maximum number of static servers within a server class.
Because it is recommended that you run your application with static servers only, you must specify
the same value for NUMSTATIC that you specify for MAXSERVERS. This way, no dynamic servers
should ever be required. If you use this approach, you can the CREATEDELAY and DELETEDELAY
attributes to default, because they apply only to dynamic servers.
The value of MAXSERVERS minus the value of NUMSTATIC equals the number of dynamic server
processes in the server class. Because the default NUMSTATIC value is zero, failing to supply a
value for NUMSTATIC causes all server processes to be dynamic. A configuration running only
dynamic server processes is not recommended because the PATHMON process does not apply
load balancing algorithms to dynamic server processes. Without load balancing, the first server
process that starts up could be overloaded. Thus, it is recommended that you supply a value for
NUMSTATIC.
The maximum number of static links that a link manager ACS subsystem processes can have is
determined by the formula NUMSTATIC * LINKDEPTH.
68 Configuring Objects in a PATHMON Environment