Monitoring poll threads with the onstat utility
About this task
While the database server is online, you cannot drop a
CPU virtual processor that is running a poll thread. To identify poll
threads that run on CPU virtual processors, use the following command:
onstat -g ath | grep 'cpu.*poll'
The
following onstat -g ath output shows two CPU virtual processors
with poll threads. In this situation, you cannot drop to fewer than
two CPU virtual processors.
tid tcb rstcb prty status vp-class name
8 a362b90 0 2 running 1cpu tlitcppoll
9 a36e8e0 0 2 cond wait arrived 3cpu
The status
field contains information,
such as running
, cond wait
, IO
Idle
, IO Idle
, sleeping secs: number_of_seconds
,
or sleeping forever
. To improve performance, you
can remove or reduce the number of threads that are identified as sleeping
forever
.
For more information on the types of virtual processors, see the chapter on virtual processors and threads in the HCL OneDB™ Administrator's Guide.
This command has an equivalent SQL administration API function.