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NAME | SYNOPSIS | DESCRIPTION | INSTALLATION | FILES | PCP ENVIRONMENT | DEBUGGING OPTIONS | SEE ALSO | COLOPHON |
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PMDADOCKER(1) General Commands Manual PMDADOCKER(1)
pmdadocker - docker performance metrics domain agent (PMDA)
$PCP_PMDAS_DIR/docker/pmdadocker [-D debug] [-d domain] [-l
logfile]
pmdadocker is a docker Performance Metrics Domain Agent (PMDA)
which exposes performance metrics as reported from the Docker
Remote API.
A brief description of the pmdadocker 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
docker.log is written in the current directory of pmcd(1)
when pmdadocker is started, i.e. $PCP_LOG_DIR/pmcd. If the
log file cannot be created or is not writable, output is
written to the standard error instead.
Remote API metric requests are activated automatically and are
fetched on a timer. This timer is represented as a by pmdadocker
via the docker.control.timing. By default, pmdadocker will be set
to fetch on a 1 second interval.
pmdadocker will iterate over three different docker remote API
calls:
/containers/$ID/json
Container metrics regarding the current state of the
container. Such as PID, name or if the container is
running.
/version
Basic version metrics about the current docker daemon in
use.
/containers/$ID/stats?stream=0
More in depth memory and cpu metrics of the container.
If you want access to the names, help text and values for the
docker performance metrics, do the following as root:
# cd $PCP_PMDAS_DIR/docker
# ./Install
If you want to undo the installation (and remove both PMDAs), do
the following as root:
# cd $PCP_PMDAS_DIR/docker
# ./Remove
pmdadocker 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.
$PCP_PMCDCONF_PATH
command line options used to launch pmdadocker
$PCP_PMDAS_DIR/docker/help
default help text file for the docker metrics
$PCP_PMDAS_DIR/docker/Install
installation script for the pmdadocker agent
$PCP_PMDAS_DIR/docker/Remove
undo installation script for the pmdadocker agent
$PCP_LOG_DIR/pmcd/docker.log
default log file for error messages and other information
from pmdadocker
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). In
particular, the $PCP_DOCKER_DIR may be set to change the default
directory from /var/lib/docker.
The -D or --debug option enables the output of additional
diagnostics on stderr to help triage problems, although the
information is sometimes cryptic and primarily intended to provide
guidance for developers rather end-users. debug is a comma
separated list of debugging options; use pmdbg(1) with the -l
option to obtain a list of the available debugging options and
their meaning.
Debugging options specific to pmdadocker are as follows:
┌────────┬────────────────────────────────────────┐
│ Option │ Description │
├────────┼────────────────────────────────────────┤
│ appl1 │ report failure to fetch stats via http │
└────────┴────────────────────────────────────────┘
PCPIntro(1), pmcd(1), pcp.conf(5), pcp.env(5) and docker(1).
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 pcp@groups.io. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2025-08-11.
(At that time, the date of the most recent commit that was found
in the repository was 2025-08-11.) 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 to
man-pages@man7.org
Performance Co-Pilot PCP PMDADOCKER(1)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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