pmlogger_check(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFIGURATION | FILES | PCP ENVIRONMENT | COMPATIBILITY ISSUES | SEE ALSO | COLOPHON

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 [-CNpqsTV?]  [-c control] [-l
       logfile]
       $PCP_BINADM_DIR/pmlogger_daily [-EfKMNoprRV?]  [-c control] [-k
       time] [-l logfile] [-m addresses] [-s size] [-t want] [-x time]
       [-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 exist).

       -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.

       -E, --expunge
            This option causes pmlogger_daily to pass the -E flag to
            pmlogger_merge in order to expunge metrics with metadata
            inconsistencies and continue rather than fail.  This is
            intended for automated daily log rotation where it is highly
            desirable for unattended daily archive merging, rewriting
            and compression to succeed.  For further details, see
            pmlogger_merge(1) and description for the -x flag in
            pmlogextract(1).

       -f, --force
            This option causes pmlogger_daily to forces action.  Using
            this option in production is not recommended.

       -k time, --discard=time
            After some period, old PCP archives are discarded.  time is
            a time specification in the syntax of find-filter(1), so
            DD[:HH[:MM]].  The optional HH (hours) and MM (minutes)
            parts are 0 if not specified.  By default the time is 14:0:0
            or 14 days, but may be changed using this option.

            Some special values are recognized for the time, namely 0 to
            keep no archives beyond the the ones being currently written
            by pmlogger(1), and forever or never to prevent any archives
            being discarded.

            The time can also be set using the $PCP_CULLAFTER variable,
            set in either the environment or in a control file.  If both
            $PCP_CULLAFTER and -k specify different values for time then
            the environment variable value is used and a warning is
            issued.  I.e., if $PCP_CULLAFTER is set in the control file,
            it overrides -k given on the command line.

            Note that the semantics of time are that it is measured from
            the time of last modification of each archive, and not from
            the original archive creation date.  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 time 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 period 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).  If $PCP_COMPRESSAFTER is set to a value
            greater than zero, then manually running pmlogger_daily with
            the -x option may be used to compress volumes that are
            younger than the $PCP_COMPRESSAFTER time.  This may be used
            to reclaim filesystem space by compressing volumes earlier
            than they would have otherwise been compressed.  Note that
            since the default value of $PCP_COMPRESSAFTER is 0 days, the
            -x option has no effect unless the control file has been
            edited and $PCP_COMPRESSAFTER has been set to a value
            greater than 0.

       -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 together.

       -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 removed.

       -p, --skip-primary
            If this option is specified for pmlogger_check then any line
            from the control files for the primary pmlogger will be
            ignored.  This option is intended for environments where
            some system daemon, like systemd(1), is responsible for
            controlling (starting, stopping, restarting, etc.) the
            primary pmlogger.

       -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.

       -q, --quick
            If this option is specified for pmlogger_check then the
            script will ``quickstart'' avoiding any optional processing
            like file compression.

       -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 options.

       -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 option.

       -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 time, --compress-after=time
            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.

            time is a time specification in the syntax of
            find-filter(1), so DD[:HH[:MM]].  The optional HH (hours)
            and MM (minutes) parts are 0 if not specified.

            Some special values are recognized for the time, namely 0 to
            apply compression as soon as possible, and forever or never
            to prevent any compression being done.

            If transparent_decompress is enabled when libpcp was built
            (can be checked with the pmconfig(1) -L option), 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 time can also be set using the $PCP_COMPRESSAFTER
            variable, set in either the environment or in a control
            file.  If both $PCP_COMPRESSAFTER and -x specify different
            values for time then the environment variable value is used
            and a warning is issued.  For important other detailed notes
            concerning volume compression, see the -K and -k options
            (above).

       -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 issued.

       -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.

CONFIGURATION         top

       Warning: The $PCP_PMLOGGERCONTROL_PATH file and files within the
       $PCP_PMLOGGERCONTROL_PATH.d directory 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(1) 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
       3.  There must be a version line in the initial control file of
           the form:
               $ 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 $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 ).
           • Any text (including white space) enclosed with ` and `
             (back quotes).
           • Any text (including white space) enclosed with " and "
             (double quotes).
           • 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.

       $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

       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

       $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, typically one per host
            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_VAR_DIR/config/pmlogger/config.default
            default pmlogger configuration file location for the local
            primary logger, typically generated automatically by
            pmlogconf(1).

       $PCP_ARCHIVE_DIR/<hostname>
            default location for archives of performance information
            collected from the host hostname

       $PCP_ARCHIVE_DIR/<hostname>/lock
            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_DIR/<hostname>/Latest
            PCP archive folio created by mkaf(1) for the most recently
            launched archive containing performance metrics from the
            host hostname

       $PCP_LOG_DIR/NOTICES
            PCP ``notices'' file used by pmie(1) and friends

       $PCP_LOG_DIR/pmlogger/pmlogger_check.log
            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.

       $PCP_LOG_DIR/pmlogger/pmlogger_daily.log
            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.

       $PCP_ARCHIVE_DIR/<hostname>/SaveLogs
            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''.

       $PCP_LOG_DIR/pmlogger/.NeedRewrite
            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.

PCP ENVIRONMENT         top

       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 checking.

COMPATIBILITY ISSUES         top

       Earlier versions of pmlogger_daily used find(1) to locate files
       for compressing or culling and the -k and -x options took only
       integer values to mean ``days''.  The semantics of this was quite
       loose given that find(1) offers different precision and semantics
       across platforms.

       The current implementation of pmlogger_daily uses find-filter(1)
       which provides high precision intervals and semantics that are
       relative to the time of execution and are consistent across
       platforms.

SEE ALSO         top

       egrep(1), find-filter(1), PCPIntro(1), pmconfig(1), pmlc(1),
       pmlogconf(1), pmlogctl(1), pmlogger(1), pmlogger_daily_report(1),
       pmlogger_merge(1), pmlogextract(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 
       ⟨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 2021-08-27.
       (At that time, the date of the most recent commit that was found
       in the repository was 2021-08-27.)  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_CHECK(1)

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