PMMGR(1)                   General Commands Manual                  PMMGR(1)

NAME         top

       pmmgr - PCP daemon manager

SYNOPSIS         top

       pmmgr [-v?]  [-c config-directory] [-p polling-interval] [-l log-
       file] [-U username]

DESCRIPTION         top

       pmmgr manages a collection of PCP daemons for a set of discovered
       local and remote hosts running the Performance Metrics Collection
       Daemon (PMCD, see pmcd(1)), according to zero or more configuration
       directories.  It keeps a matching set of pmie(1), pmlogger(1),
       pmrep(1) and other daemons running, and their archives/logs
       merged/rotated.  It provides an alternative to the default
       pmlogger_daily(1) and pmie_daily(1) scripts that administer pmlogger
       and pmie ``farms'' using cron(3).

       pmmgr is largely self-configuring and perseveres despite most run-
       time errors.  pmmgr runs in the foreground until interrupted.  When
       signaled, it will stop its running daemons before exiting.

ALGORITHM         top

       Each poll interval, pmmgr computes a list of possible targets for a
       pmcd search.  This list is assembled from several configuration
       files, and may include explicitly listed specifications, hosts
       discovered through several different mechanisms, and/or individual
       containers running within them.  Once the list is assembled, pmmgr
       attempts to make a brief pmNewContext connection to each target, in
       order to check for the existence of an actual running pmcd instance,
       and to extract a hostid.  The hostid is treated as a unique
       identifier for the instance, so that redundant connection paths to
       the same server can be filtered out.  Once the final list of live
       pmcd instances is identified, along with their unique hostids, pmmgr
       ensures that any requested PCP client daemons are started (or
       restarted) for them.  If any pmcd instances disappear from the list,
       its PCP client daemons are stopped.  This entire cycle repeats every
       poll interval.

OPTIONS         top

       The available command line options are:

       -c directory, --config=directory
            Adds a given configuration directory to pmmgr.  pmmgr can
            supervise multiple different configurations at the same time, so
            this option may be repeated.  Errors in the configuration may be
            noted to standard error, but pmmgr will fill in missing
            information with built-in defaults.  The default directory is

       -l logfile, --log=logfile
            Redirect standard output and error to the given logfile, which
            is created anew.

       -p interval, --poll=interval
            Set the host-discovery polling interval to the given number of
            seconds.  The default is 60.  Daemons for a particular target
            host will be restarted no more frequently than this interval.
            There may be a short-lived thread inside pmmgr for startup and
            shutdown of each daemon for each target host.

       -U username, --username=username
            Switch from the root to user username on startup.  The default
            is pcp.

       -v   Enable verbose mode.

       -?   Display usage message and exit.


       A pmmgr configuration identifies which hosts should be monitored,
       which daemons should be maintained for them, and what options those
       daemons should be run with.  pmmgr uses a small number of files in a
       configuration directory, instead of lines in a single text file.  The
       individual files carry zero or more lines of 100% pure configuration
       text, and no comments.  (If desired, a configuration may be commented
       upon within other files, such as a free-form README.)

       Some of the configuration files are forked into pairs: per-hostid and
       common.  This permits numerous almost-identical-configuration targets
       to be managed from the same configuration directory.  For these
       files, marked with * below, pmmgr will concatenate a per-hostid file
       (if it exists) and a common file (if it exists) in order to form the
       complete configuration item.

       For example, for pmie configuration for target hostid foo, pmmgr will
       search files named then pmie.  For single-line configuration
       items, the first file & line found will "win"; for multi-line
       configuration items, they all "win".

       This set of configuration files identifies where pmmgr should search
       for pmcd instances, how to uniquely identify them, and where state
       such as log files should be kept for each.  Ideally, a persistent and
       unique hostid string is computed for each potential target pmcd from
       specified metric values.  This hostid is also used as a subdirectory
       name for locating daemon data.  The rare empty hostid is mapped to

              This file contains one or more lines specifying the static
              string that should be used as multiple distinct hostids for
              the same target pmcd.  Treatment of the distinct hostids may
              be customized using per-hostid configuration files.
              Specifying values in this file overrides the hostid-metrics
              file specified below.  It should be noted that using this
              option will cause all target pmcds to be assigned the same set
              of hostids.  Thus, this is useful in monitoring single hosts
              or if each monitored host has its own configuration directory.

              This file contains one or more lines of metric specifications
              in the format accepted by pmParseMetricSpec.  Metrics without
              instance specifiers mean all instances of that metric.  These
              are used to generate the unique hostid string for each pmcd
              server that pmmgr discovers.  Upon discovery, all the
              metrics/instances named are queried, string values fetched,
              and normalized/concatenated into a single hyphenated printable
              string.  The default is the single metric pmcd.hostname, which
              is sufficient if all the hosts discovered have unique
              hostname.  If they don't, you should add other pcp metric
              specifications to set them apart at your site.  The more you
              add, the longer the hostid string, but the more likely that
              accidental duplication is prevented.

       However, it may be desirable for a hostid to also be persistent, so
       that if the target host goes offline and later returns, the new
       hostid matches the previous one, because then old and new histories
       can be joined.  This argues against using metrics whose values vary
       from boot to boot.

       Some candidate metrics to consider: network.interface.hw_addr,
       network.interface.inet_addr["eth0"], network.interface.ipv6_addr,

              This file contains the path of a directory beneath which the
              per-hostid subdirectories are to be created by pmmgr.  If it
              is not a full path, it is implicitly relative to the
              configuration directory itself.  The default is

              This file contains one or more lines containing pmcd host
              specifications, as described on the PCPIntro(1) manual page.
              The default is to target pmcd at local:.

              This file contains one or more lines containing specifications
              for the pmDiscoverServices PMAPI call, each of which may map
              onto a fluctuating set of local or remote pmcd servers.  Each
              poll interval, pmmgr will attempt to rerun discovery with all
              of the given specifications.  Again, it is not a problem if
              more than one specification matches the same actual pmcd: one
              confirmed access path is arbitrarily selected.  The default is
              to do no discovery.  Consider including avahi,timeout=5 to
              rely in pmcd self-announcements on the local network
              (searching for up to five seconds each time).  Consider
              including probe= to quickly scan the given IP
              address range.

              If this file exists, pmmgr will scan each host that is found
              for running containers.  For each running container, it will
              create independent subtargets for running requested daemons.
              The hostid string for these subtargets is the host's hostid
              string, followed by a double-hyphen, then the full unique
              container instance-name string.

              This file contains a limit on the number of concurrent threads
              that analyze potential target pmcds for their hostids and/or
              containers.  The default is a few dozen threads per CPU core,
              if known.  Set this to zero if remote pmcds should be analyzed
              sequentially.  A small number of threads is not a good idea if
              any potential target pmcds are unreachable, since
              $PMCD_CONNECT_TIMEOUT may be several seconds long each.

              This file may contain a time interval specification as per the
              PCPIntro(1) manual page.  All subdirectories of the
              log-directory are presumed to contain data for pmmgr-monitored
              servers.  Those that have not been modified in at least that
              long, and not associated with a currently monitored target,
              are deleted entirely.  This value should be longer than the
              longest interval that pmmgr normally recreates archives (such
              as due to pmmgr restarts, and pmlogmerge intervals).  The
              default value is 90days.

       This group of configuration options controls a pmlogger daemon for
       each host.  This may include generating its configuration, and
       managing its archives.

              If and only if this file exists, pmmgr will maintain a
              pmlogger daemon for each targeted host.  This file contains
              one line of additional space-separated options for the
              pmlogger daemon.  (pmmgr already adds -h, -H, -f, -r, -l, and
              perhaps -c.)  The default is to maintain no pmlogger (and no
              other configuration in this section is processed).

              Specify a time format to use in the archive-* name for
              pmlogger generated archives.  The default is %Y%m%d.%H%M%S.
              Expected to be in strftime(3) format.

              If and only if this file exists, pmmgr will run pmlogconf to
              generate a configuration file for each target pmcd.  The file
              contains one line of space-separated additional options for
              the pmlogconf program.  pmlogconf's generated output file will
              be stored under the log-directory/hostid subdirectory.  (pmmgr
              already adds -c, -r, and -h.)  The default is no pmlogconf, so
              instead, the pmlogger file above should probably contain a -c
              option, to specify a fixed pmlogger configuration.

       Default pmlogger configurations can collect tens of megabytes of data
       per day (possibly split into multiple archives), per target host.  If
       your disk space is less than infinite, or archive-splitting unwieldy,
       this should be managed.  In the default, unmanaged case, the system
       administrator is responsible for managing the individual archive-*
       files from the per-host logging subdirectories.  pmmgr offers several
       other options, each representing different performance and usability

       This style of archive log management regularly creates a single
       merged archive from prior archives for each target host, in effect
       lopping off old data and appending the new.  A single merged archive
       can be relatively large (defaults to approximately 100-400 MB per
       host), and puts a corresponding I/O load on storage, but is most
       convenient for a detailed long-timeframe analysis.  Once pmlogger is
       restarted, it always creates a new archive, so in the steady state,
       there will be one merged archive of recent history, and one current
       archive being written-to by pmlogger.

              If this file exists, pmmgr will run pmlogextract to
              periodically merge together preexisting log archives for each
              target pmcd into a single large one.  Then, the preexisting
              log archives are deleted (including any prior merged ones).
              This configuration file may contain a time interval
              specification as per the PCPIntro(1) manual page, representing
              the period after which pmlogger should be temporarily stopped,
              and archives merged.  It represents the maximum amount of time
              that the merged archive lags the present time.  The default is

              If this file also exists, pmmgr will merge only a subset of
              preexisting log archives into the new one, instead of all of
              them, so as to approximate a granular, aligned set of merged
              archives.  The subset chosen corresponds to the previous time
              interval specified by the pmlogmerge control file.  The
              default is no granularity.

              Before archives are considered for merging, they are processed
              through pmlogcheck to check for corruption.  In the unlikely
              case of a problem, such archives are renamed out of the way
              (named "corrupt-*"), and retained up to a limited time.  This
              file specifies how long.  If this file exists, it the time
              interval it contains is the maximum age.  The default is
              90days.  To store corrupt archives indefinitely, set this to a
              large quantity like 99999weeks.

              If this file exists, pmmgr will run pmlogrewrite -i (plus any
              other options listed in this file) on each input archive
              before merging it.  This will naturally require more disk I/O.
              The default is no rewriting.

              pmmgr reduces/deletes any original-resolution archives after a
              time period specified by this file, as measured by the file
              mtime.  The period will also be passed to pmlogextract as a
              negative parameter to -S.  The default is 14days.  To store
              archives indefinitely, set this to a large quantity like

              If this file exists, then prior to removing archives that
              expire past the pmlogmerge-retain period, they are processed
              with pmlogreduce to create reduced archives (named reduced-*).
              If the file contains space-separated options, they are passed
              onto pmlogreduce.  (By default, pmlogreduce down-samples to a
              600-second interval.)

              If this file exists, then reduced archives (identified by the
              reduced-* pattern) are deleted after a time period specified
              by this file, as measured from the file mtime.  Since this
              time is likely that of the pmlogreduce run, the total
              retention time will be approximately the pmlogmerge-retain
              time plus the pmlogreduce-retain time.  The default is 90days.
              To store reduced archives indefinitely, set this to a large
              quantity like 99999weeks.

              If this file exists, then pmmgr will track the disk space
              available where pmlogger archives are kept.  If that partition
              fills up past the configured percentage, pmmgr will linearly
              reduce the duration logs are kept via the disk-full-retention

       Values must be greater than zero, and expressed either a value
       between 0 and 1, or decimal value between 1 and 100.

              If expressed, this variable scales the rate at which logs are
              culled when disk-full-threshold has been surpassed.  A lower
              percentage will cull logs more quickly (in favour of
              preserving disk space), while a higher percentage will opt to
              retain more pcp archives.

           │Normalized Full Threshold │ Full Retention │ Final Retention Factor │
           │            1             │      0.0       │          0.0           │
           │          0.75            │      0.0       │          0.25          │
           │           0.5            │      0.0       │          0.5           │
           │           0.0            │      0.0       │          1.0           │
           │            1             │      0.5       │          0.5           │
           │          0.75            │      0.5       │         0.625          │
           │           0.5            │      0.5       │          0.75          │
           │           0.0            │      0.5       │          1.0           │
           │            1             │      1.0       │          1.0           │
           │          0.75            │      1.0       │          1.0           │
           │           0.5            │      1.0       │          1.0           │
           │           0.0            │      1.0       │          1.0           │
       This group of configuration options controls a pmie daemon for each
       host.  This may include generating a custom configuration.

       pmie*  If and only if this file exists, pmmgr will maintain a pmie
              daemon for each targeted pmcd.  This file contains one line of
              additional space-separated options for the pmie daemon.
              (pmmgr already adds -h, -f, -l, and perhaps -c.)  The default
              is to maintain no pmie (and no other configuration in this
              section is processed).

              If and only if this file exists, pmmgr will run pmieconf to
              generate a configuration file for each target pmcd.  The file
              contains one line of space-separated additional options for
              the pmieconf program.  pmieconf- generated output file will be
              stored under the log-directory/hostid subdirectory.  (pmmgr
              already adds -F, -c, and -f.)  The default is no pmieconf, so
              instead, the pmie file above should probably contain a -c
              option, to specify a fixed pmie configuration.

       pmmgr may be used to invoke arbitrary PCP client programs for each
       target pmcd(1).  This can enable automated invocation of reporting or
       relaying tools, such as pmrep(1), pcp2graphite(1) or pcp2influxdb(1)
       without needing a specialized system service.

              If this file exists, then for each line in this file, a new
              background process will be invoked.  (It is restarted if it
              exits.)  The line specifies the beginning of the command line
              (including the program name); pmmgr appends a -h HOSTSPEC, and
              arranges to collect the standard output and standard error
              into separate monitor-NN.out and monitor-NN.err files under
              the log directory.  Errors messages in the latter are
              transcribed to pmmgr's own logs.

FILES         top

            default configuration directory

            default logging directory


       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         top

       PCPIntro(1), cron(1), pmcd(1), pmlogconf(1), pmlogger(1),
       pmlogger_daily(1), pmlogreduce(1), pmie(1), pmieconf(1),
       pmie_daily(1), pmrep(1), pcp2graphite(1), pcp2influxdb(1),
       pcp.conf(5) and pcp.env(5).

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
       2020-02-08.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-02-06.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
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       (which is not part of the original manual page), send a mail to

Performance Co-Pilot                 PCP                            PMMGR(1)

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