By default, sp_sysmon does not clear the monitor counters that are used as source data for the report. If other applications or instances of the sp_sysmon report are running when this is done, clearing the counters may cause the data that they report to be invalid.
Use the optional noclear parameter with sp_sysmon to not clear the monitor counters. For example:
sp_sysmon “00:15:00”, noclear
This example runs the sp_sysmon report
for a 15-minute sample interval without clearing the monitor counters.
You can use the value of noclear for any
of these parameters which lets you specify noclear in combination
with other parameter values:
@section
@applmon
@filter
@dumpcounters
For example, to create the report for kernel resource use
while using the noclear option, issue:
sp_sysmon “00:15:00”, kernel, noclear
When you run sp_sysmon with
the noclear option, you may
detect a slight increase in the amount of I/O activity
at the beginning of the sample period. The report must create a
temporary table in which to store initial counter values. The impact
of this activity on the data reported by sp_sysmon should be
negligible on any but the most quiescent systems.
Because Monitor Server uses the same monitor counters that
the sp_sysmon report does, Sybase recommends
that you use the noclear option
when running sp_sysmon at the same time
that Monitor Server is running. You can also run multiple concurrent
sessions of sp_sysmon reports by using
the noclear option. Consider
whether other system monitoring applications that you are running use
the monitor counters. If they do, use the noclear option when
running sp_sysmon.
When you execute sp_sysmon 'end_sample' from a session that is different from the one on which you executed 'begin_sample', sp_sysmon does not decrement the monitor counters and Adaptive Server returns error message number 19374 to the client. This means that, if an application enables the monitor counters and does not disable them before logging out, the usage count continues to reflect the same number of users as it did before the application logged out.
