pmlogger_check(1) — Linux manual page


PMLOGGER_CHECK(1)          General Commands Manual         PMLOGGER_CHECK(1)

NAME         top

       pmlogger_check,  pmlogger_daily  -  administration of Performance Co-
       Pilot archive log files

SYNOPSIS         top

       $PCP_BINADM_DIR/pmlogger_check [-CNsTV?]  [-c control] [-l logfile]
       $PCP_BINADM_DIR/pmlogger_daily [-KMNoprRV?]  [-c control] [-k
       discard] [-l logfile] [-m addresses] [-s size] [-t want] [-x
       compress] [-X program] [-Y regex]

DESCRIPTION         top

       These shell scripts and associated control files may be used to
       create a customized regime of administration and management for
       Performance Co-Pilot (see PCPIntro(1)) archive log files.

       pmlogger_check may be run at any time of the day and is intended to
       check that a desired set of pmlogger(1) processes are running.  If
       not, it (re-)starts any missing logger processes.

       pmlogger_daily 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 one or more sets
       of PCP archives.

       To accommodate the evolution of PMDAs and changes in production
       logging environments, pmlogger_daily is integrated with
       pmlogrewrite(1) to allow optional and automatic rewriting of archives
       before merging.  If there are global rewriting rules to be applied
       across all archives mentioned in the control file(s), then create the
       directory $PCP_SYSCONF_DIR/pmlogrewrite and place any pmlogrewrite(1)
       rewriting rules in this directory.  For rewriting rules that are
       specific to only one family of archives, use the directory name from
       the control file(s) - i.e. the fourth field - and create a file, or a
       directory, or a symbolic link named pmlogrewrite within this
       directory and place the required rewriting rule(s) in the
       pmlogrewrite file or in files within the pmlogrewrite subdirectory.
       pmlogger_daily will choose rewriting rules from the archive directory
       if they exist, else rewriting rules from
       $PCP_SYSCONF_DIR/pmlogrewrite if that directory exists, else no
       rewriting is attempted.

       As an alternate mechanism, if the file
       $PCP_LOG_DIR/pmlogger/.NeedRewrite exists when pmlogger_daily starts
       then this is treated the same as specifying -R on the command line
       and $PCP_LOG_DIR/pmlogger/.NeedRewrite will be removed once all the
       rewriting has been done.

OPTIONS         top

       -c control, --control=control
            Both pmlogger_check and pmlogger_daily are controlled by PCP
            logger control file(s) that specifies the pmlogger instances to
            be managed.  The default control file is
            $PCP_PMLOGGERCONTROL_PATH, but an alternate may be specified
            using the -c option.  If the directory
            $PCP_PMLOGGERCONTROL_PATH.d (or control.d from the -c option)
            exists, then the contents of any additional control files
            therein will be appended to the main control file (which must

       -C   This option causes pmlogger_check to query the system service
            runlevel information for pmlogger, and use that to determine
            whether to start processes or not.

       -k period, --discard=period
            After some period, old PCP archives are discarded.  This period
            is 14 days by default, but may be changed using this option.
            Some special values are recognized for the period, namely 0 to
            keep no archives beyond the current one, and forever or never to
            prevent any archives being discarded.  Note that the semantics
            of discard are that it is measured from the time of last
            modification of each archive, and not from the current day.
            This has subtle implications for compression (see below) - the
            compression process results in the creation of new archive files
            which have new modification times.  In this case, the discard
            period (re)starts from the time of compression.

       -K   When this option is specified for pmlogger_daily then only the
            compression tasks are attempted, so no pmlogger rotation, no
            culling, no rewriting, etc.  When -K is used and a compress
            value of 0 is in effect (from -x on the command line or
            PCP_COMPRESSAFTER in the environment or via the control file)
            this is intended for environments where compression of archives
            is desired before the scheduled daily processing happens.  To
            achieve this, once pmlogger_check has completed regular
            processing, it calls pmlogger_daily with just the -K option.
            Provided PCP_COMPRESSAFTER is set to 0 along with any other
            required compression options to match the scheduled invocation
            of pmlogger_daily, then this will compress all volumes except
            the ones being currently written by pmlogger(1).

       -l file, --logfile=file
            In order to ensure that mail is not unintentionally sent when
            these scripts are run from cron(8) diagnostics are always sent
            to log files.  By default, this file is
            $PCP_LOG_DIR/pmlogger/pmlogger_check.log or
            $PCP_LOG_DIR/pmlogger/pmlogger_daily.log but this can be changed
            using the -l option.  If this log file already exists when the
            script starts, it will be renamed with a .prev suffix
            (overwriting any log file saved earlier) before diagnostics are
            generated to the log file.  The -l and -t options cannot be used

       -m addresses, --mail=addresses
            Use of this option causes pmlogger_daily to construct a summary
            of the ``notices'' file entries which were generated in the last
            24 hours, and e-mail that summary to the set of space-separated
            addresses.  This daily summary is stored in the file
            $PCP_LOG_DIR/NOTICES.daily, which will be empty when no new
            ``notices'' entries were made in the previous 24 hour period.

       -M   This option may be used to disable archive merging (or renaming)
            and rewriting (-M implies -r).  This is most useful in cases
            where the archives are being incrementally copied to a remote
            repository, e.g. using rsync(1).  Merging, renaming and
            rewriting all risk an increase in the synchronization load,
            especially immediately after pmlogger_daily has run, so -M may
            be useful in these cases.

       -N, --showme
            This option enables a ``show me'' mode, where the programs
            actions are echoed, but not executed, in the style of ``make
            -n''.  Using -N in conjunction with -V maximizes the diagnostic
            capabilities for debugging.

       -o   By default all possible archives will be merged.  This option
            reinstates the old behaviour in which only yesterday's archives
            will be considered as merge candidates.  In the special case
            where only a single input archive needs to be merged, pmlogmv(1)
            is used to rename the archive, otherwise pmlogger_merge(1) is
            used to merge all of the archives for a single host and a single
            day into a new PCP archive and the individual archives are

       -p   If this option is specified for pmlogger_daily then the status
            of the daily processing is polled and if the daily pmlogger(1)
            rotation, culling, rewriting, compressing, etc.  has not been
            done in the last 24 hours then it is done now.  The intent is to
            have pmlogger_daily called regularly with the -p option (at 30
            mins past the hour, every hour in the default cron(8) set up) to
            ensure daily processing happens as soon as possible if it was
            missed at the regularly scheduled time (which is 00:10 by
            default), e.g. if the system was down or suspended at that time.
            With this option pmlogger_daily simply exits if the previous
            day's processing has already been done.  The -K and -p options
            to pmlogger_daily are mutually exclusive.

       -r, --norewrite
            This command line option acts as an override and prevents all
            archive rewriting with pmlogrewrite(1) independent of the
            presence of any rewriting rule files or directories.

       -R, --rewriteall
            Sometimes PMDA changes require all archives to be rewritten, not
            just the ones involved in any current merging.  This is required
            for example after a PCP upgrade where a new version of an
            existing PMDA has revised metadata.  The -R command line forces
            this universal-style of rewriting.  The -R option to
            pmlogger_daily is mutually exclusive with both the -r and -M

       -s size, --rotate=size
            If the PCP ``notices'' file ($PCP_LOG_DIR/NOTICES) is larger
            than 20480 bytes, pmlogger_daily will rename the file with a
            ``.old'' suffix, and start a new ``notices'' file.  The rotate
            threshold may be changed from 20480 to size bytes using the -s

       -s, --stop
            Use of this option provides the reverse pmlogger_check
            functionality, allowing the set of pmlogger processes to be
            cleanly shutdown.

       -t period
            To assist with debugging or diagnosing intermittent failures the
            -t option may be used.  This will turn on very verbose tracing
            (-VV) and capture the trace output in a file named
            $PCP_LOG_DIR/pmlogger/daily.datestamp.trace, where datestamp is
            the time pmlogger_daily was run in the format YYYYMMDD.HH.MM.
            In addition, the period argument will ensure that trace files
            created with -t will be kept for period days and then discarded.

       -T, --terse
            This option to pmlogger_check produces less verbose output than
            the default.  This is most suitable for a pmlogger ``farm''
            where many instances of pmlogger are expected to be running.

       -V, --verbose
            The output from the cron execution of the scripts may be
            extended using the -V option to the scripts which will enable
            verbose tracing of their activity.  By default the scripts
            generate no output unless some error or warning condition is
            encountered.  Using -N in conjunction with -V maximizes the
            diagnostic capabilities for debugging.

       -x period, --compress-after=period
            Archive data files can optionally be compressed after some
            period to conserve disk space.  This is particularly useful for
            large numbers of pmlogger processes under the control of
            pmlogger_check.  If transparent_decompress is enabled when
            libpcp was built (can be checked with the pmconfig(1) -Loption),
            then the default behaviour is compression ``as soon as
            possible''.  Otherwise the default behaviour is to not compress
            files (which matches the historical default behaviour in earlier
            PCP releases).  The -x option specifies the number of days after
            which to compress archive data and metadata files.  If compress
            is 0 then compression will be applied as soon as possible.  If
            compress is never or forever then no compression will be done.
            The environment variable PCP_COMPRESSAFTER may be used as an
            alternative mechanism to define compress.  If both
            PCP_COMPRESSAFTER and -x specify different values for compress
            then the environment variable value is used and a warning is

       -X program, --compressor=program
            This option specifies the program to use for compression - by
            default this is xz(1).  The environment variable PCP_COMPRESS
            may be used as an alternative mechanism to define program.  If
            both PCP_COMPRESS and -X specify different compression programs
            then the environment variable value is used and a warning is

       -Y regex, --regex=regex
            This option allows a regular expression to be specified causing
            files in the set of files matched for compression to be omitted
            - this allows only the data file to be compressed, and also
            prevents the program from attempting to compress it more than
            once.  The default regex is
            ".(index|Z|gz|bz2|zip|xz|lzma|lzo|lz4)$" - such files are
            filtered using the -v option to egrep(1).  The environment
            variable PCP_COMPRESSREGEX may be used as an alternative
            mechanism to define regex.  If both PCP_COMPRESSREGEX and -Y
            specify different values for regex then the environment variable
            value is used and a warning is issued.

       -?, --help
            Display usage message and exit.


       Warning: The $PCP_PMLOGGERCONTROL_PATH and
       $PCP_PMLOGGERCONTROL_PATH.d 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

       1.  Lines beginning with a ``#'' are comments.
       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,
               $ PMCD_CONNECT_TIMEOUT=20
       3.  There must be a version line in the initial control file of the
               $ version=1.1
       4.  There should be one line in the control file(s) for each pmlogger
           instance of the form:

               host y|n y|n directory args

       5.  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 for some important exceptions).
       6.  The first field is the name of the host that is the source of the
           performance metrics for this pmlogger instance.
       7.  The second 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.
       8.  The third field indicates if this pmlogger instance needs to be
           started under the control of pmsocks(1) to connect to a pmcd
           through a firewall (y or n).
       9.  The fourth field is a directory name.  All 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 in the maintenance of 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
       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 ).
           · Any text (including white space) enclosed with ` and ` (back
           · Any text (including white space) enclosed with " and " (double
           · Any word containing a $ (assumed to introduce an environment
             variable name).
       11. All other fields are interpreted as arguments to be passed to
           pmlogger(1).  Most typically this would be the -c option.

       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 and boing.

       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

       Typical crontab(5) entries for periodic execution of pmlogger_daily
       and pmlogger_check are given in $PCP_SYSCONF_DIR/pmlogger/crontab
       (unless installed by default in /etc/cron.d already) and shown below.

       # daily processing of archive logs
       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.

FILES         top

            the PCP logger control file
            Warning: this file must not be writable by any user other than

            optional directory containing additional PCP logger control
            files, typically one per host
            Warning: the files herein must not be writable by any user other
            than root.

            sample crontab for automated script execution by $PCP_USER (or
            root).  Exists only if the platform does not support the
            /etc/cron.d mechanism.

            default pmlogger configuration file location for the local
            primary logger, typically generated automatically by

            default location for archives of performance information
            collected from the host hostname

            transient lock file to guarantee mutual exclusion during
            pmlogger administration for the host hostname - if present, can
            be safely removed if neither pmlogger_daily nor pmlogger_check
            are running

            PCP archive folio created by mkaf(1) for the most recently
            launched archive containing performance metrics from the host

            PCP ``notices'' file used by pmie(1) and friends

            if the previous execution of pmlogger_check produced any output
            it is saved here.  The normal case is no output in which case
            the file does not exist.

            if the previous execution of pmlogger_daily produced any output
            it is saved here.  The normal case is no output in which case
            the file does not exist.

            if this directory exists, then the log file from the -l argument
            of a newly launched pmlogger(1) for hostname will be linked into
            this directory with the name archive.log where archive is the
            basename of the associated pmlogger(1) PCP archive files.  This
            allows the log file to be inspected at a later time, even if
            several pmlogger(1) instances for hostname have been launched in
            the interim.  Because the cron-driven PCP archive management
            scripts run under the uid of the user ``pcp'',
            $PCP_ARCHIVE_DIR/hostname/SaveLogs typically needs to be owned
            by the user ``pcp''.

            if this file exists, then this is treated as equivalent to using
            -R on the command line and the file will be removed once all
            rewriting has been done.


       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).

       The default behaviour, when pmlogger(1) configuration comes from
       pmlogconf(1), is to regenerate the configuration file and check for
       changes whenever pmlogger(1) is started from pmlogger_check.  If the
       PMDA configuration is stable, this is not necessary, and setting
       $PMLOGGER_CHECK_SKIP_LOGCONF to yes disables the regeneration and

SEE ALSO         top

       egrep(1), PCPIntro(1), pmconfig(1), pmlc(1), pmlogconf(1),
       pmlogger(1), pmlogger_daily_report(1), pmlogger_merge(1), pmlogmv(1),
       pmlogrewrite(1), pmsocks(1), systemd(1), xz(1) and cron(8).

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at ⟨⟩.
       If you have a bug report for this manual page, send it to  This page was obtained from the project's upstream
       Git repository ⟨⟩ on
       2020-06-09.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-06-09.)  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

Performance Co-Pilot                 PCP                   PMLOGGER_CHECK(1)

Pages that refer to this page: pcpintro(1)PCPIntro(1)pmdumplog(1)pmfind_check(1)pmlogextract(1)pmlogger(1)pmloglabel(1)pmsnap(1)logarchive(5)LOGARCHIVE(5)