TS/MP 2.5 System Management Manual

Step 1 Identify Number of Pathsend Requestors and Terminals
Identify how many Pathsend requestors and, if your environment includes Pathway/iTS, how many
terminals your application environment must support. Multiply these by a safety factor—for example,
1.5—to allow for future application growth. The formula for Pathsend requestors is:
Pathsend requestors x constant = total Pathsend requestors
The formula for terminals is:
terminals x constant = total terminals
For example:
2000 existing terminals x 1.5 = 3000 total terminals
Step 2 Determine Total Link Manager Processes (LINKMON/ACS subsystem processes)
and TCPs Required
Your application has one link manager process per processor. If your environment includes
Pathway/iTS, a good rule of thumb is to configure one TCP for every 50 terminals. For example:
6 CPUs x 1 LINKMON per CPU = 6 LINKMON processes
3000 terminals
= 60 TCPs50 terminals per TCP
Step 3 Calculate Working Average Transaction Volume
Identify the types of transactions the application is to handle, such as inquiries, withdrawals, or
summing transactions. For each transaction type, estimate the average transaction volume, or
arrival rate, and multiply it by a safety factor (constant)—for example, 1.5—to allow for fluctuations
in transaction volume. The result is the working average transaction volume in transactions per
second.
The calculation must be done for each transaction; then the results are applied to each serve class.
The formula is:
avg. transaction vol. x constant = working avg. transaction vol.
For example:
30 transactions per second x 1.5 = 45 transactions per second
(tps)
where “1.5” is the safety factor and the working average transaction volume is expressed in
transactions per second.
NOTE: Because Steps 4-6 must be calculated on a per-server-class basis, a spreadsheet could
be helpful to record and calculate the required values.
Step 4 Measure Server Class Response Time
Assuming that each server class provides one service, use the Measure product to determine server
class response time.
Step 5 Calculate Active Links for Each Transaction
For each transaction type that accesses the server class, calculate the number of active links required
by that transaction type.
working avg. transaction vol. x server class process response
time = active links
where active links is transactions of a given type in progress in the server class, working
avg. transaction vol. is the result of your calculation in Step 3, and server class
process response time is the result of Step 4.
Configuring Links for Optimum Performance 71