pmdatrace is a Performance Metrics Domain Agent (PMDA) which exports
transaction performance metrics from application processes which use
the pcp_trace library described in pmdatrace(3).
A brief description of the pmdatrace command line options follows:
-d It is absolutely crucial that the performance metrics domain
number specified here is unique and consistent. That is, domain
should be different for every PMDA on the one host, and the same
domain number should be used for the same PMDA on all hosts.
-l Location of the log file. By default, a log file named
trace.log is written in the current directory of pmcd(1) when
pmdatrace is started, i.e. $PCP_LOG_DIR/pmcd. If the log file
cannot be created or is not writable, output is written to the
standard error instead.
-A Host-based access control for pmdatrace. access must be either
an allow or deny specification, using either
allow:hostspec:maxconns or disallow:hostspec, where `allow' and
`disallow' are keywords, `hostspec' is a host specification
conforming to the format used by both pmcd(1) and pmlogger(1),
and `maxconns' is the maximum number of connections allowed from
a given `hostspec'. Using a maximum connections of zero
specifies an unlimited number of connections for the
-I Communicate with pcp_trace clients via the given Internet port.
This can alternatively be specified by setting $PCP_TRACE_PORT
in the environment to some valid port number (use of the -I
option overrides this). The default port number is 4323.
-T period defines the aggregation period used to compute the recent
averages and extrema. Specified as a time interval using the
syntax described in PCPIntro(1) for the common -t PCP argument,
e.g. 30 seconds or 1 min. The default is 60 seconds.
-M User account under which to run the agent. The default is the
unprivileged "pcp" account in current versions of PCP, but in
older versions the superuser account ("root") was used by
-N Internally, the aggregation period is divided into bucket
divisions, and the rolling average is recomputed every
period/bucket seconds. For example, the defaults correspond to
-T 60 and -N 12, which means the average is recomputed every
five seconds for a period covering the prior 60 seconds.
-U This option allows the dimension and scale associated with the
observation value metric to be configured. units is a comma-
separated string of six integer values, which are the space
dimension, time dimension, count dimension, space scale, time
scale, and count scale, respectively. The default dimension and
scale is ``none'', which is equivalent to presenting
``0,0,0,0,0,0'' as the argument to -U. The units associated
with a metric are most easily viewed using the -d (metric
description) option to pminfo(1). The Install script described
below steps through this option quite explicitly, so it is
recommended that the Install script be used for building up the
Essentially, the exported metrics provide statistics on the time for
completion of each transaction, and an average count of transactions
completed and watch points passed over a given time period.
In order for a host to export the names, help text and values for the
Trace performance metrics, do the following as root:
# cd $PCP_PMDAS_DIR/trace
If you want to undo the installation, do the following as root:
# cd $PCP_PMDAS_DIR/trace
pmdatrace is launched by pmcd(1) and should never be executed
directly. The Install and Remove scripts notify pmcd(1) when the
agent is installed or removed.
command line options used to launch pmdatrace$PCP_PMDAS_DIR/trace/help
default help text file for the trace metrics
example programs which use the pcp_trace library
installation script for the pmdatrace agent
undo installation script for pmdatrace$PCP_LOG_DIR/pmcd/trace.log
default log file for error messages and other information
Environment variables with the prefix PCP_ are used to parameterize
the file and directory names used by PCP. On each installation, the
file /etc/pcp.conf contains the local values for these variables.
The $PCP_CONF variable may be used to specify an alternative
configuration file, as described in pcp.conf(5).
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at ⟨http://www.pcp.io/⟩.
If you have a bug report for this manual page, send it to
firstname.lastname@example.org. This page was obtained from the project's upstream
Git repository ⟨git://git.pcp.io/pcp⟩ on 2017-03-13. If you discover
any rendering problems in this HTML version of the page, or you
believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
Performance Co-Pilot PCP PMDATRACE(1)