Pathway/XM System Management Manual

Managing Servers
Compaq NonStop™ Pathway/XM System Management Manual—426761-001
9-3
Direct and Replicated Server Classes
The LCS process starts new server processes in parallel with the servicing of the
transaction queue by existing server processes. As a result, the overhead associated with
starting a new process is outside the path of the transaction.
Direct and Replicated Server Classes
When a server class of type DIRECT or REPLICATED is started, the number of server
processes initially created is determined by the value of the NUMSTATIC attribute for
the server class.
In a direct or replicated server class, there are two types of server processes, static and
dynamic.
•
A static server is a server process that is created when you issue the START
SERVER command.
•
A dynamic server is a temporary server process that is created and started in
response to an increase in transaction workload. This type of server is not
dependent on the START SERVER command.
Static Server Processes
When you issue a START SERVER command for a direct or replicated server class, the
PATHMON process(es) start the number of static servers defined for the server class.
This number is defined by the NUMSTATIC attribute in the SET SERVER statement.
For example, if the value for the NUMSTATIC attribute for the server class
ORDER-SRV is 5, the following command causes 5 static server processes to be created
in the server class named ORDER-SRV:
>> START SERVER ORDER-SRV
In response to the START SERVER command, the PATHMON process performs the
following startup operations for each static server process in the server class:
•
Creates and starts the server process by running the program specified in the
PROGRAM attribute of the SERVER definition, using all attributes configured in
the SET SERVER statements.
•
Sends a startup message to the server process, describing Guardian environment
information for that process. This message indicates the names of the input and
output files and the default volume and subvolume used by the process, and any
optional message text.
•
Passes any ASSIGN and PARAM assignments to the server process.
Dynamic Server Processes
For direct and replicated server classes, the PATHMON process creates a dynamic
server process when a link manager (a LINKMON process or TCP) asks for a link and
no links to static servers are available. Note that if the link manager has determined that
no more static links are available, it asks for a new link only after send requests have