pmlogger.control(5) — Linux manual page
PMLOGGER.CONTROL(5) File Formats Manual PMLOGGER.CONTROL(5)
NAME
pmlogger.control - control files for Performance Co-Pilot
archiving
DESCRIPTION
Historical archiving of performance data for Performance Co-Pilot
(see PCPIntro(1)) uses pmlogger(1) and one or more instances of
pmlogger may be managed by pmlogger_check(1) and
pmlogger_daily(1).
pmlogger_check(1) may be run at any time of the day and is
intended to check that the desired set of pmlogger processes are
running. If not, it (re-)starts any missing logger processes.
By default, pmlogger_check(1) also calls pmlogger_daily(1) with a
-K option to execute any required archive compression tasks.
pmlogger_daily(1) is intended to be run once per day, preferably
in the early morning, as soon after midnight as practicable. Its
task is to aggregate, rotate and perform general housekeeping for
one or more sets of PCP archives.
Both pmlogger_check(1) and pmlogger_daily(1) operate on a family
of shared control files, namely the $PCP_PMLOGGERCONTROL_PATH
file and files within the $PCP_PMLOGGERCONTROL_PATH.d directory.
These files must not be writable by any user other than root.
The control file(s) should be customized according to the
following rules that define for the current version (1.1) of the
control file format.
1. Lines beginning with a ``#'' are comments. A special case is
lines beginning ``#!#''; these are control lines for a
pmlogger that has been stopped using pmlogctl(1).
2. Lines beginning with a ``$'' are assumed to be assignments to
environment variables in the style of sh(1), and all text
following the ``$'' will be eval'ed by the script reading the
control file, and the corresponding variable exported into
the environment. This is particularly useful to set and
export variables into the environment of the administrative
scripts, e.g.
$ PMCD_CONNECT_TIMEOUT=20
If the value to the right of the ``='' contains any white
space, then the value should be enclosed in double (") or
single (') quotes.
3. There must be a version line in the control file of the form:
$version=1.1
4. Fields within a line of the control file(s) are usually
separated by one or more spaces or tabs (although refer to
the description of the directory field below for some
important exceptions).
5. There should be one line in the control file(s) for each
pmlogger instance with at least 4 fields of the form:
host primary socks directory args ...
6. The host field is the name of the host that is the source of
the performance metrics for this pmlogger instance. The
reserved word LOCALHOSTNAME will be replaced by the name of
the local host.
7. The primary field indicates if this is a primary pmlogger
instance (y) or not (n). Since the primary logger must run
on the local host, and there may be at most one primary
logger for a particular host, this field can be y for at most
one pmlogger instance, in which case the host name must be
the name of the local host (or LOCALHOSTNAME).
8. The socks field indicates if this pmlogger instance needs to
be started under the control of pmsocks(1) to connect to a
pmcd(1) through a firewall (y or n).
9. The directory field is a directory name. All archive files
associated with this pmlogger instance will be created in
this directory, and this will be the current directory for
the execution of any programs required to maintain those
archives. A useful convention is that primary logger
archives for the local host with hostname myhost are
maintained in the directory $PCP_ARCHIVE_DIR/myhost (this is
where the default pmlogger start-up script in $PCP_RC_DIR/pcp
will create the archives), while archives for the remote host
mumble are maintained in $PCP_ARCHIVE_DIR/mumble.
10. The directory field may contain embedded shell syntax that
will be evaluated by sh(1) to produce the real directory name
to be used. The allowed constructs are:
• Any text (including white space) enclosed with $( and )
will be interpreted as a shell command.
• Any text (including white space) enclosed with ` and `
(back quotes) will be interpreted as a shell command.
• Within a single line only one style of embedded shell
command is allowed, so either $(...) or `...`, but not
both.
• An initial double quote (") followed by arbitrary text
(including white space, but excluding an embedded double
quote) and a final double quote.
• An initial single quote (') followed by arbitrary text
(including white space, but excluding an embedded single
quote) and a final single quote.
• Any word containing a $ (assumed to introduce an
environment variable name).
11. In the directory field, the reserved word LOCALHOSTNAME will
be replaced by the name of the local host.
12. The optional args field and any remaining fields are
interpreted as arguments to be passed to pmlogger(1). Most
typically this would be at least the -c option to specify the
metrics to be logged and the logging frequencies.
The following sample control lines specify a primary logger on
the local host (bozo), and non-primary loggers to collect and log
performance metrics from the hosts wobbly, boing and the local
host (i.e. bozo).
$version=1.1
bozo y n $PCP_ARCHIVE_DIR/bozo -c config.default
wobbly n n "/store/wobbly/$(date +%Y)" -c ./wobbly.config
boing n n $PCP_ARCHIVE_DIR/boing -c ./pmlogger.config
LOCALHOSTNAME n n /cluster/LOCALHOSTNAME -c ./precious.config
SCHEDULED EXECUTION
The periodic execution of pmlogger_check(1) and pmlogger_daily(1)
is controlled by either systemd(1) or cron(8).
Typical crontab(5) entries are provided in
$PCP_SYSCONF_DIR/pmlogger/crontab (unless installed by default in
/etc/cron.d already) and shown below.
# daily processing of archives
14 0 * * * $PCP_BINADM_DIR/pmlogger_daily
# every 30 minutes, check pmlogger instances are running
25,55 * * * * $PCP_BINADM_DIR/pmlogger_check
When using systemd(1) on Linux, no crontab entries are needed as
the timer mechanism provided by systemd is used instead to
achieve the same period execution as the crontab example above.
FILES
$PCP_PMLOGGERCONTROL_PATH
the PCP logger control file. For a new installation this
file contains no pmlogger(1) control lines (the real control
files are all in the $PCP_PMLOGGERCONTROL_PATH.d directory),
but this file is still processed to support any legacy
configurations therein from earlier PCP releases.
Warning: this file must not be writable by any user other
than root.
$PCP_PMLOGGERCONTROL_PATH.d
optional directory containing additional PCP logger control
files, with one or more per pmlogger specification per file.
Warning: the files herein must not be writable by any user
other than root.
$PCP_SYSCONF_DIR/pmlogger/crontab
sample crontab for automated script execution by $PCP_USER
(or root). Exists only if the platform does not support the
/etc/cron.d mechanism.
PCP ENVIRONMENT
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).
SEE ALSO
PCPIntro(1), pmcd(1), pmlogctl(1), pmlogger(1),
pmlogger_check(1), pmlogger_daily(1), pmlogger_daily_report(1),
pmsocks(1), systemd(1) and cron(8).
COLOPHON
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 2024-06-14.
(At that time, the date of the most recent commit that was found
in the repository was 2024-06-14.) 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 PMLOGGER.CONTROL(5)
Pages that refer to this page: pmlogger_check(1), pmlogger_daily(1)