Provided by: pcp-manager_4.0.1-1_amd64 
NAME
pmmgr - pcp daemon manager
SYNOPSIS
pmmgr [-v] [-c config-directory] [-p polling-interval] [-l log-file]
DESCRIPTION
pmmgr manages a collection of PCP daemons for a set of discovered local and remote hosts
running the Performance Metrics Collection Daemon (PMCD), according to zero or more
configuration directories. It keeps a matching set of pmie, pmlogger, pmrep and other
daemons running, and their archives/logs merged/rotated. It provides an alternative to
the default pmlogger_daily and pmie_daily 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
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
A description of the command line options specific to pmmgr follows:
-c 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
$PCP_SYSCONF_DIR/pmmgr
-p polling-interval sets 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.
-l log-file redirects standard output and error to the given log file, which is created
anew
-v adds more verbose tracing to standard output.
CONFIGURATION
FILES
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
pmie.foo then pmie. For single-line configuration items, the first file & line found will
"win"; for multi-line configuration items, they all "win".
TARGET SELECTION
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 "-".
hostid-static
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.
hostid-metrics
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(2). 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, kernel.uname.nodename
log-directory
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
$PCP_LOG_DIR/pmmgr/.
target-host
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:.
target-discovery
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=192.168.1.0/24 to
quickly scan the given IP address range.
subtarget-containers
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.
target-threads
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.
log-subdirectory-gc
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.
PMLOGGER CONFIGURATION
This group of configuration options controls a pmlogger daemon for each host. This may
include generating its configuration, and managing its archives.
pmlogger*
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).
pmlogger-timefmt*
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.
pmlogconf*
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.
ARCHIVE LOG MANAGEMENT
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 tradeoffs.
ARCHIVE LOG MANAGEMENT - pmlogmerge
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.
pmlogmerge*
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 24hours.
pmlogmerge-granular*
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.
pmlogcheck-corrupt-gc*
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".
pmlogmerge-rewrite*
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.
pmlogmerge-retain*
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 "99999weeks".
pmlogreduce*
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.)
pmlogreduce-retain*
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".
disk-full-threshold
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
variable.
Values must be greater than zero, and expressed either a value between 0 and 1, or
decimal value between 1 and 100.
disk-full-retention
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 │
└──────────────────────────┴────────────────┴────────────────────────┘
PMIE CONFIGURATION
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).
pmieconf*
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.
MONITOR DAEMON MANAGEMENT
pmmgr may be used to invoke arbitrary PCP client programs for each target pmcd. This can
enable automated invocation of reporting or relaying tools, such as pmrep, pcp2graphite or
pcp2influxdb without needing a specialized system service.
monitor*
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
$PCP_SYSCONF_DIR/pmmgr/
default configuration directory
$PCP_LOG_DIR/pmmgr/
default logging directory
PCP ENVIRONMENT
Environment variables with the prefix PCP_ are used to parametrize 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), cron(1), pmcd(1), pmlogconf(1), pmlogger(1), pmlogger_daily(1), pmieconf(1),
pmie(1), pmie_daily(1), pmrep(1), pcp2graphite(1), pcp2influxdb(1), pmlogreduce(1),
pcp.conf(5) and pcp.env(5).