DOKK / manpages / debian 12 / pcp / pmlogconf.1.en
PMLOGCONF(1) General Commands Manual PMLOGCONF(1)

pmlogconf - create/edit a pmlogger configuration file

pmlogconf [-cqrvV?] [-d groupsdir] [-g grouptag] [-h host] [-s groupfile] configfile

pmlogconf may be used to create and modify a generic configuration file for the PCP archive logger, pmlogger(1).

If configfile does not exist, pmlogconf will create a generic configuration file with a default set of enabled metrics and logging intervals.

Once created, configfile may be used with the -c option to pmlogger(1) to select performance metrics and specify logging intervals for a PCP archive.

If configfile does exist, pmlogconf will prompt for input from the user to enable or disable groups of related performance metrics and to control the logging interval for each enabled group.

Group selection requires a simple y (yes) or n (no) response to the prompt Log this group?.

Other responses at this point may be used to select additional control functions as follows:

Report the names of the metrics in the current group.
Finish with group selection (quit) and make no further changes to this group or any subsequent group.
/pattern
Make no change to this group but search for a group containing pattern in the description of the group or the names of the associated metrics.

A logging interval is specified by responding to the Logging interval? prompt with the keywords once or default or a valid pmlogger(1) interval specification of the form ``every N timeunits'' or simply ``N timeunits '' (the every is optional) where N is an unsigned integer and timeunits is one of the keywords msec, millisecond, sec, second, min, minute, hour or the plural form of one of the keywords.

When run from automated logging setup processes, the -c option is used to indicate that pmlogconf is in auto-create mode and no interactive dialog takes place. The output configfile has an additional comment message and timestamp indicating this fact, so that it can be identified and subsequently updated using -c again. This option is not appropriate for interactive use of the tool.

The -q option suppresses the logging interval dialog and preserves the current interval from configfile.

More verbose output may be enabled with the -v option.

When an initial configfile is created, the default specifications come from a set of group files below the groupsdir specified with the -d option (the default groupsdir is $PCP_VAR_DIR/config/pmlogconf which is most commonly correct, so the -d option is rarely used in practice).

The directory structure below groupsdir is arbitrary as all regular files will be found by recursive descent and considered, so add-on products and PMDA developers can easily extend the available defaults to pmlogconf by adding new directories and/or group files below groupsdir.

These group files are processed in the following ways:

  • When a new configfile is created, all group files are processed.
  • Whenever pmlogconf is run with an existing configfile, groupsdir is traversed to see if any new groups have been defined and should be considered for inclusion in configfile.
  • When pmlogconf processes a group in configfile that is enabled, the list of metrics associated with the group is taken from the group file (and replaces any previous list of metrics associated with this group in configfile).
  • When either the -r (reprobe) or the -c (auto-create) command line option is specified, every group (not just newly discovered ones) is reprocessed to see if it should be considered for inclusion in configfile.
  • If a group is found in configfile but the corresponding group does not exist below groupsdir (as would be the case when a group is made obsolete by a PCP upgrade) then the handling of the group depends on the mode in which pmlogconf is being run. With -c the corresponding group is culled from configfile, otherwise the corresponding group is unchanged in configfile. In either case a warning is issued.

Each group file is structured as follows:

  • The first line must contain #pmlogconf-setup 2.0
  • Other lines beginning with # are treated as comments.
  • Blank lines are ignored.
  • One or more lines starting with the keyword ident are used to provide the human-readable description of the group.
  • Non-blank lines beginning with white space define metrics to be associated with this group, one per line. Each metric specification follows the rules for a pmlogger(1) configuration, namely either the name of a non-leaf node in the PMNS (implying all descendent names in the PMNS), or the name of a leaf node in the PMNS optionally followed by one or more instance names enclosed by ``['' and ``]''.
  • A control line starting with one of the keywords probe or force must be present.
  • An optional logging interval control line begins with the keyword delta followed by one of the pmlogger(1) interval specification described above.
  • probe control lines have the format:


probe metric [condition [state_rule] ]

where metric is the name of a PCP metric (must be a leaf node in the PMNS, no instance specification is allowed, and it must not be a derived metric) and the optional condition is the keyword exists (true if metric exists, i.e. is defined in the PMNS) or the keyword values (true if metric exists in the PMNS and has one or more current values) or an expression of the form

op val
where op is one of the awk(1) operators (==, !=, >, >=, <, <=, ~ (regular expression match) or !~ (negated regular expression match)) and val is a value (arbitrary sequence of characters, excluding a space) and the condition is true if there is some instance of metric that makes the expression true.

If the condition is missing, the default is exists.

When an explicit condition is provided, there may also be an optional state_rule of the form

? true_state : false_state
where true_state (applies if condition is true) and false_state (applies if condition is false) are both taken from the keywords include (include and enable the group and the associated metrics in configfile), available (include and disable the group in configfile - a user action of y as described above is needed to enable the group and add the associated metrics into configfile) or exclude (the group is not considered for inclusion in configfile).

The default state_rule is

? available : exclude

•
force control lines begin with the keyword force followed by one of the states defined above, so one of the actions include, exclude or available is applied unconditionally to the group.

Probing is only done when a new group is being added to configfile or when the -r command line option is specified. The evaluation of the probing conditions is done by contacting pmcd(1) on hostname (defaults to local:).

The available command line options are:

Enable non-interactive, auto-create mode.
Specify the path to the groupsdir directory.
Query logging state for the specific logging group named grouptag.
Performance metrics source is pmcd(1) on host, rather than on the default localhost.
Quiet mode, suppress logging interval dialog.
Reconsider every group for inclusion in the configfile.
Report the default logging state for the one logging group in groupfile. This is equivalent output to that produced by the retired pmlogconf-setup shell script from earlier versions of PCP.
Enable verbose mode.
Display version number and exit.
-?, --help
Display usage message and exit.

The following group file demonstrates all of the supported syntactic elements.

#pmlogconf-setup 2.0
ident   Example group file
ident   ... more description
delta   1 minute
probe   sample.secret.foo.one values ? include : exclude


        sample.secret.foo.one


        sample.secret.foo.bar   # non-leaf in the PMNS


        sample.colour [ red green ]

The current version of pmlogconf (2.0) supports a slightly different format for configfile compared to earlier versions. If an old version configfile is presented to pmlogconf it will be converted to the new format.

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).

pmlogconf overrides any $PCP_DERIVED_CONFIG environment variable to an empty string, for performance reasons.

pmlogconf honours the $PMCD_WAIT_TIMEOUT environment variable when probing and creating new pmlogger configuration files. It uses a default timeout value of 10 seconds for this, in the absence of an environment setting.

pmcd(1), pmlogger(1), pcp.conf(5) and pcp.env(5).

PCP Performance Co-Pilot