Collecting data on one node, Collecting data – HP XC System 3.x Software User Manual
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Collecting Data on One Node
To collect data on one node in a cluster environment, you can use the procedures described in
and
with the following additional guidelines:
•
Do not start the hpcpid daemon on each node.
•
Do not start the daemon from a script that is executed on every node.
•
If you are using the hpcpictl label command, execute the distribution utility (such as
mpirun
) from the hpcpictl label command (hpcpictl label...mpirun...).
•
Do not execute the hpcpictl label command from the distribution utility
(mpirun...hpcpictl label...).
Starting a Distribution Utility from hpcpictl label
When you collect performance data from only one node in the job allocation and use an HPCPI
label, start the distribution utility from the hpcpictl label command. HPCPI establishes the
label only on one node, and the hpcpid daemon needs to be running on that node only.
If you start the distribution utility from the hpcpictl label command and the utility creates
a new process group for the application it launches, you cannot use the -pid this or -pgid
this
selectors to capture data from the application. Instead, you can use the -uid option to
associate the label with events from processes running with your UID. For example:
% hpcpictl label mylabel -uid this mpirun [mpi_opts] myApp
The data associated with the label includes the overhead data for the distribution utilities (the
mpirun
and scheduler processes) that run with your UID, but this data is trivial when compared
to the data for most applications.
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