Pathway/iTS System Management Manual (G06.24+)

Tuning Your System Using Statistics
HP NonStop Pathway/iTS System Management Manual—426748-002
5-22
I/O Info
AVG TSIZE
AVG TSIZE indicates the size of the average data transfer for the DISPLAY, ACCEPT,
SEND, and REPLY statements and for checkpoint operations.
DISPLAY Statements
For DISPLAY, AVG TSIZE indicates the size of the average buffer sent to the terminal.
If the number indicated for AVG TSIZE is greater than that specified for TERMBUF,
multiple I/O operations are required to display the data. To reduce the number of I/O
operations required to display the data, you should:
•
Increase the size of TERMBUF (using the SET TCP TERMBUF command) to
MAXTSIZE +8.
•
Increase the size of TERMPOOL (using the SET TCP TERMPOOL command) by
the corresponding amount.
I/O CNT
I/O CNT indicates the number of physical I/O operations (when the TCP actually writes
data to the terminal or sends data to a server) generated by the SCREEN COBOL
DISPLAY, ACCEPT, or SEND statements.
Statistics are not provided for REPLY statements because there are no explicit
requests for REPLY. Statistics are not provided for CHECKPOINT operations because
the TCP performs more checkpoint operations than there are SCREEN COBOL
checkpoint requests.
Block-Mode Terminals
For terminals running in block mode, the TCP writes data to the terminal when:
•
The buffer is full.
•
An ACCEPT statement is executing.
For some block-mode terminals (6500-series terminals and 3270 terminals in
SNAX and AM configurations), the ACCEPT statement generates two I/O
operations: the first I/O reads the key; the second I/O reads the data.
•
Any of the DISPLAY statements are followed by certain other SCREEN COBOL
statements, such as DELAY.
You can specify the size of the output buffer allocated from TERMPOOL with the
SET TCP TERMBUF command. If the buffer is large enough, the TCP need not write
data to the terminal simply because the buffer is full.
The minimum DISPLAY I/O CNT for block-mode terminals is equal to ACCEPT REQ
CNT.