ODBC Server Installation and Management Manual

Managing the NonStop ODBC Server
HP NonStop ODBC Server Installation and Management Manual—429395-002
4-3
Checking the Status of the NonStop ODBC Server
System
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Run the application and analyze the server statistics. If you get complaints about
slow connection time, you must increase the AVAILABLE_SERVERS value. If you
get no complaints, begin to reduce the AVAILABLE_SERVERS value.
The time required for a client to connect is the smallest when the value of TOTAL
CONNECTED is equal to the value of LISTENING HIT. If these values are equal,
there was always a listening server available when a client connection request
arrived.
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To find the smallest AVAILABLE_SERVERS value, you must begin to reduce the
value assigned to this parameter until the TOTAL CONNECTED values exceed the
LISTENING HIT number. This scenario occurs when a client attempts to connect
and must wait for an available server (either for SCS to start one or for another
client to release one).
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When TOTAL CONNECTED values exceed LISTENING HIT values, increase
AVAILABLE_SERVERS by increments of one until the values are equal.
The result should yield a system that gives the fastest connect time with a
minimum number of servers kept in the available pool for the server class.
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Next, check the HIGH CONNECTED value. This value represents the highest
number of concurrent connections to the server class. In this example, it is likely
that this value will be considerably less than 75. If, for example, you see a HIGH
CONNECTED value of 50, meaning at most 50 clients were connected at one
time, you can reduce MAXSERVERS from 75. Determine the new MAXSERVERS
value with the following formula:
MAXSERVERS = (HIGH-CONNECTED + (HIGH-CONNECTED * 10%) )
The additional 10 percent should cover those unlikely situations in which usage is
higher than normal and also allows you to add new users without immediately
taking down the SQL Communication Subsystem (SCS).
Checking the Status of the NonStop ODBC Server System
The SCS product is released with a TACL macro for collecting status information about
the NonStop ODBC Server system. To use this macro, you must first attach the TACL
segment file used by the macro.
To attach the TACL segment file, enter the following command:
RUN $vol.znos.ATTACH $vol.znos
where $vol.znos is the volume and subvolume in which the NonStop ODBC Server
software is installed. Having attached this TACL segment, you can then use the
commands described in this subsection for managing the SCS and NonStop ODBC
Server system processes.
After starting the NonStop ODBC Server system, check on all the processes running
for that system.