TMF Reference Manual (G06.26+)

TMFCOM Commands
HP NonStop TMF Reference Manual—522418-003
3-119
ALTER TMF
guideline, if your primary TMP is experiencing very high interrupt time (above 30%), try
setting the TMPWAITTIMER to this value.
In addition to a discrete value, you can specify AUTO to direct TMF to re-calculate the
transaction wait timer value every 10 seconds based on average transaction duration.
You can also specify OFF to disable the timer, in which case the TMP processes each
request as the request is received.
If you set the TMPWAITTIMER value to OFF (the default value), the TMP awakens
each time a request arrives. The OFF setting creates additional TMP overhead and
may keep the primary TMP too busy, resulting in reduced transaction throughput. In
lightly loaded systems where the response time for short transactions is critical, the
OFF setting can benefit performance. In heavily loaded systems, the OFF setting may
provide greater throughput but TMP processor usage will be increased.
If TMF is started, the value you specify usually takes effect in 10 seconds.
You may need to experiment to determine the optimal values for PIOBUFFER and
TMPWAITTIMER in your particular environment. Because these values can be
changed while TMF is running, you can make small changes while monitoring
performance to determine the best values for your system.
Examples
This ALTER TMF command changes the configuration volume from $SYSTEM to
$CAT01:
TMF 76> ALTER TMF, CONFIGVOL $CAT01
The following command switches the primary and backup TMP processes:
TMF 77> ALTER TMF, SWITCHPROCESS TMP
The following command moves from format 1 to format 2 audit-trail files; the transition
occurs when you restart TMF:
TMF 78> ALTER TMF, ATFORMAT 2
Note. Before RVU G06.26, the TMPWAITTIMER attribute could only be set through the
SNOOP utility, which used AUTO as the default value for this attribute. However, RVU G06.26
makes the TMPWAITTIMER attribute accessible through the TMFCOM ALTER TMF command
and now uses OFF as the default value for both new and existing configurations. Thus, after
you install RVU G06.26 and then issue your first START TMF command, your existing TMF
configuration will be affected as follows:
•
If you did not change the TMPWAITTIMER value from the AUTO default value in
the previous RVU, TMF will change the TMPWAITTIMER value from AUTO to OFF
when TMF starts, and will issue an EMS message announcing this change.
•
If you changed TMPWAITTIMER to a value other than AUTO in the previous RVU,
TMF will retain the value you then assigned.