Tandem Capacity Model (TCM) Manual

Significant Row
1. User-Supplied Transaction Names—Not directly modifiable
The name of the transaction as it appears on the Workload Apportionment screens. Transaction
names are either initially defined on the NonStop host system using MeasTCM (see “TXN
Entries” (page 59)) or named by default in TCM by server category (type S), but they can be
overwritten on the Workload Apportionment screens by the TCM administrator.
Significant Columns
2. Cat Name—Not directly modifiable
Cat Name is the category name of all process categories as they appear on the Category
Demand report. These categories appear in rows in the Apportionment Weights table. The
table indicates how the CPU and disk seconds consumed by these categories are to be allocated
to each transaction.
3. Type—Modifiable by the TCM administrator
Type is the type of process category, as defined in MeasTCM on the NonStop host system.
The category type consists of one of the following characters:
Server processS
Requester processR
Disk process (including all nonaudited disk processes)D
TMF processes (including all audit disk processes)T
Linehandler processL
OtherO
Fixed (system overhead that does not vary with throughput)F
Ignore these categories (appropriate interrupt and disk activity to be omitted)Z
4. Tunable CPU—Modifiable by the TCM administrator
Tunable CPU indicates, for batch transactions only, whether all process category activity occurs
in one or multiple CPUs. It is ignored for online transactions. The process category CPU activity
is either monolithic or spread evenly across all CPUs that are available for batch activity. The
default is Y (yes) for categories that participate in at least one OLTP transaction. The default
is N (no) for categories that participate only in batch transactions.
For example, in the Demo model included with TCM, the Tape Read and Cust Update
categories are not tunable. That is, they are assigned to run in specific CPUs. However, the
FastSort category is tunable. It runs in all CPUs.
After the WA model recalculates the tunable CPU values in Figure 41 (page 118) they will be
reflected in the Workload detail by Category screen.
5. Expert Flag—Modifiable by the TCM administrator
Expert Flag shows whether TCM Expert generates a value for the process category. The default
for the TMF (T), Disk (D), Fixed (F), and Ignore (Z) process categories is N (no). The default is
also N for server categories whose names exactly match the transaction names because a
process category that has the same name as a server is assumed to have all activity for that
server. The default value for all other process categories is Y (yes).
6. Transaction—Modifiable by the TCM administrator
The TCM administrator uses the Transaction columns to indicate the relative weights with which
the CPU, disk read, and disk write seconds of a category should be apportioned to transactions.
A default version of the table is created by selecting Workload Apportionment from the Update
tab and selecting Create Default Apportionment Tables from the dialog box that appears or
Workload Apportionment Weights Table 117