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

Tuning Your System Using Statistics
HP NonStop Pathway/iTS System Management Manual—426748-002
5-9
POOL INFO
SIZE
SIZE indicates the maximum number of bytes available in each pool, as determined by
the TCP’s configuration. If this number is consistently low (the value for MAX ALLOC is
near the value for SIZE), terminal tasks are using most of the available pool space; in
this case, you might want to increase the size of the pools.
You can derive the currently available pool space by using this formula:
FREEPOOL = SIZE - CUR ALLOC
You can use this formula to determine whether to increase pool size:
IF SIZE - MAX ALLOC < AVG REQ or MAX REQ
THEN increase pool size
These allocations use memory to improve performance. If there are memory
shortages, you might consider reducing these allocations.
To determine a sufficient size for each pool, use the guidelines described next.
TERMPOOL
TERMPOOL, specified with the SET TCP TERMPOOL command, indicates the
minimum number of bytes that the TCP allocates in its data area for all terminal I/O
buffers.
To determine a sufficient initial size for TERMPOOL, use this formula. (For these
calculations, PATHMON-controlled PROGRAM objects count as terminals.) Note that
these allocations use memory to improve performance. If there are memory shortages,
you might consider reducing these allocations.
TERMPOOL = MAXTERMS * TERMBUF
TERMBUF governs the size of the output buffer. For input, the TCP locks down an
appropriate size buffer in TERMPOOL without regard to the TERMBUF setting.
Generally speaking, the output buffer is larger than the input buffer. If an application on
your system could potentially have a larger buffer to be read in than to be written out,
use the read buffer size when determining TERMBUF size.
•
MAXTERMS
specified with the SET TCP MAXTERMS command, indicates the maximum
number of terminals that the TCP can have open at the same time. To determine
the current value for MAXTERMS, use the INFO TCP command.
•
TERMBUF
specified with the SET TCP TERMBUF command, indicates the maximum number
of bytes that the TCP allocates from the TERMPOOL area for terminal output
buffers. If you do not specify a value for TERMBUF, the default is 1500.
To determine the current value for TERMBUF, use the INFO TCP command.
TERMBUF size is not a factor in READs or SEND messages. The following are
guidelines for specifying the size of TERMBUF: