Pathway/XM System Management Manual

Configuring Servers
Compaq NonStop™ Pathway/XM System Management Manual—426761-001
6-7
Configuring the MAXSERVERS and NUMSTATIC
Attributes
To ensure that Pathway/XM can create as many processes as needed, you should
compile your server programs with the ?HIGHPIN attribute set to ON, and you should
set the HIGHPIN attribute to ON for all server classes in your configuration.
For more information about running processes in your Pathway/XM environment at
high versus low PINs, refer to the manuals that describe system management for your
version of the NonStop™ TS/MP and Pathway/iTS products.
Configuring the MAXSERVERS and NUMSTATIC Attributes
The MAXSERVERS and NUMSTATIC attributes are closely related. The meanings of
these two attributes differ depending on the setting of the TYPE attribute for the server
class (DISTRIBUTED, DIRECT, or REPLICATED).
Distributed Server Classes
For distributed server classes, the NUMSTATIC attribute defines the number of server
process reservations that each LCS process holds permanently under each PATHMON
process for the server class. The MAXSERVERS attribute defines the total maximum
number of server process reservations that can be distributed for this server class by all
LCS processes in the Pathway/XM environment. (During some internal Pathway/XM
operations, it is possible for up to twice the specified number of server process
reservations to be active simultaneously, for a very short time.)
When you specify NUMSTATIC for a distributed server class, at least the number of
static servers you specify are kept running for the entire server class. The specified
NUMSTATIC value is adjusted according to the number of PATHMON processes so
that each PATHMON process has the same number of static servers and so that the total
number of static servers across all PATHMON processes equals the adjusted
NUMSTATIC value. The adjusted value is calculated to be as close as possible to the
originally specified value.
It is recommended that you set NUMSTATIC to the minimum number of server
processes you expect to need in the server class at any time, and MAXSERVERS to the
maximum number of server processes you expect to need.
Distributed server classes have only one LCS process, although a TCP can establish
multiple links to that one LCS. If you set NUMSTATIC to 0 for the server class (which
also sets it to 0 for the LCS), the first link established by the TCP is identified as a
dynamic link. This causes the TCP to act as if there are no more static links available
and wait the CREATEDELAY time before requesting another link. The default for
CREATEDELAY is 1 minute. This delay time can degrade the burst mode response.
Direct and Replicated Server Classes
For direct server classes, the NUMSTATIC attribute defines the number of server
processes to be created when the server class is started. The MAXSERVERS attribute
specifies the maximum number of server processes in this server class that can run at the
same time. If MAXSERVERS is greater than NUMSTATIC, additional server
processes are created at run time in response to increased transaction workload for the
server class.