PMVAL(1)

📦
version 7.2.2 · 6 versions
, in arch rolling, fedora 43, fedora 44, ubuntu stonking

✨ PMVAL(1) — General Commands Manual ✨

okay bestie, welcome to the iconic little manual page for pmval (and its secret twin pmevent), the tool that dumps arbitrary performance metrics values 💖

💖 NAME 💖

pmval, pmevent — arbitrary performance metrics value dumper 🫶

🌸 SYNOPSIS 🌸

pmval [-dgLrvVXz?]  [-a archive] [-A align] [--container=name] [-D
       debug] [--derived=file] [-f N] [-h host] [-i instances] [-K spec] [-n
       pmnsfile] [-O offset] [-p port] [-s samples] [-S starttime] [-t
       interval] [-T endtime] [-U archive] [-w width] [-x pattern] [-Z
       timezone] metricname

       pmevent ...

🦋 DESCRIPTION 🦋

pmval prints current or archived values for the nominated performance metric, bestie. The metric you care about is named in the metricname argument, and it can be qualified by instances with the -i flag like the section below explains 💅

Unless you point it somewhere else with -h, or give it a set of archives with -a or -U, pmval will go talk to the Performance Metrics Collector Daemon (PMCD) on the local host to get the info it needs. localhost core, no cap 👑

The metricname argument can also use the metric specification syntax from PCPIntro(1), where the source, metric, and instance can all live inside metricname, like this:

thathost:kernel.all.load["1 minute"]

When you use that format, none of the -h, -a, or -U options may be specified. periodt.

When you're using the metric specification syntax, the @ “hostname” is treated specially ✨ It makes pmval use a local context to collect metrics from PMDAs on the local host without PMCD. Only some metrics are available in this mode, so don't expect the whole menu, okay? 🙈

When processing a set of archives, pmval may hand over its own timing control and operate under the control of a pmtime(1) process that uses a GUI dialog to provide timing control. In that case, either the -g option should be used to start pmval as the sole client of a new pmtime(1) instance, or -p should be used to attach pmval to an existing pmtime(1) instance via the IPC channel identified by the port argument 🎀

The -S, -T, -O, and -A options may be used to define a time window to restrict the samples retrieved, set an initial origin within the time window, or specify a “natural” alignment of the sample times. Refer to PCPIntro(1) for a complete description of these options 💫

The output from pmval is directed to standard output. These symbols may occasionally show up in place of a metric value, so don't be confused, bestie:

  • A question mark symbol (?) indicates that a value is no longer available for that metric instance 😭
  • An exclamation mark (!) indicates that a 64-bit counter wrapped during the sample 💀

pmevent is an alias for pmval. iconic.

✨ OPTIONS ✨

The available command line options are:

  • -a archive, --archive=archive — Performance metric values are retrieved from the set of Performance Co-Pilot (PCP) archive files identified by the archive argument. That argument is a comma-separated list of names, and each name may be the base name of an archive or the name of a directory containing one or more archives. See also -U 💖
  • -A align, --align=align — Force the initial sample to be aligned on the boundary of a natural time unit align. Refer to PCPIntro(1) for a complete description of the syntax for align ✨
  • --container=container — Specify an individual container to be queried.
  • -d, --delay — When replaying from an archive, this option requests that the prevailing real-time delay be applied between samples (see -t) to effect a pause, rather than the default behaviour of replaying at full speed. lowkey chill mode 🫶
  • --derived=file — Load derived metric definitions from file.
  • -f precision, --precision=precision — Numbers are reported in “fixed point” notation instead of the default scientific notation, using precision digits for precision. Each number will be up to the column width determined by the default heuristics, or else the -w option if specified, and will include precision digits after the decimal point. So, the options -f 3 -w 8 would produce numbers of the form 9999.999. A value of zero for precision omits the decimal point and any fractional digits 💅
  • -g, --guimode — Start pmval as the sole client of a new pmtime(1) server process for replay of archived performance data using the pmtime(1) graphical user interface 🎀
  • -h host, --host=host — Fetch performance metrics from pmcd(1) on host, rather than from the default localhost 🌸
  • -i instances, --instances=instances — Specify a list of one or more names of instances for the nominated performance metric — just these instances will be retrieved and reported (the default is to report all instances). The list must be a single argument, with elements of the list separated by commas and/or white space.

The instance name may be quoted with single (') or double (") quotes for those cases where the instance name contains white space or commas.

Multiple -i options are allowed as an alternative way of specifying more than one instance of interest.

As an example, the following are all equivalent:

$ pmval -i "'1 minute','5 minute'" kernel.all.load
$ pmval -i '"1 minute","5 minute"' kernel.all.load
$ pmval -i "'1 minute' '5 minute'" kernel.all.load
$ pmval -i "'1 minute'" -i "'5 minute'" kernel.all.load
$ pmval 'localhost:kernel.all.load["1 minute","5 minute"]'
  • -K spec, --spec-local=spec — When fetching metrics from a local context (see -L), the -K option may be used to control the DSO PMDAs that should be made accessible. The spec argument conforms to the syntax described in pmSpecLocalPMDA(3). More than one -K option may be used 💜
  • -L, --local-PMDA — Use a local context to collect metrics from DSO PMDAs on the local host without PMCD. See also -K.
  • -n pmnsfile, --namespace=pmnsfile — Load an alternative Performance Metrics Name Space (PMNS(5)) from the file pmnsfile.
  • -O origin, --origin=origin — When reporting archived metrics, start reporting at origin within the time window (see -S and -T). Refer to PCPIntro(1) for a complete description of the syntax for origin ⭐
  • -p port, --guiport=port — Attach pmval to an existing pmtime(1) time control process instance via the IPC channel identified by the port argument. This option is normally only used by other tools, e.g. pmchart(1), when they launch pmval with synchronized time control 🫶
  • -r, --raw — Print raw values for cumulative counter metrics. Normally cumulative counter metrics are converted to rates. For example, disk transfers are reported as number of disk transfers per second during the preceding sample interval, rather than the raw value of number of disk transfers since the machine was booted. If you specify this option, the raw metric values are printed. no glow-up math, just the real numbers 💅
  • -s samples, --samples=samples — The samples argument defines the number of samples to be retrieved and reported. If samples is 0 or -s is not specified, pmval will sample and report continuously (in real time mode) or until the end of the set of PCP archives (in archive mode) 🌈
  • -S starttime, --start=starttime — When reporting archived metrics, the report will be restricted to those records logged at or after starttime. Refer to PCPIntro(1) for a complete description of the syntax for starttime 💖
  • -t interval, --interval=interval — Set the reporting interval to something other than the default 1 second. The interval argument follows the syntax described in PCPIntro(1), and in the simplest form may be an unsigned integer (the implied units in this case are seconds) ⏰
  • -T endtime, --finish=endtime — When reporting archived metrics, the report will be restricted to those records logged before or at endtime. Refer to PCPIntro(1) for a complete description of the syntax for endtime 🌙
  • -U archive, --nointerp=archive — Performance metric values are retrieved from the Performance Co-Pilot (PCP) archive. The argument is a comma-separated list of names, each of which may be the base name of an archive or the name of a directory containing one or more archives. However, unlike -a, every recorded value in the archive for the selected metric and instances is reported (so no interpolation mode, and the sample interval (-t option) is ignored). See also -a.
At most one of the options -a and -U may be specified. pick a lane, bestie 😌
  • -v, --verbose — Enable verbose mode. spill the tea ☕
  • -V, --version — Display version number and exit.
  • -w width, --width=width — Set the width of each column of output to be width columns. If not specified, columns are wide enough to accommodate the largest value of the type being printed 📏
  • -x pattern, --filter=pattern — The given pattern is sent to the performance metric domain agent for the requested metricname before any values are requested. This serves two purposes. Firstly, it provides a mechanism for server-side event filtering that is customisable for individual event streams. In addition, some performance metrics domain agents also use the PMCD store mechanism to provide a basic security model (e.g. for sensitive log files, only a client host with pmStore(3) access would be able to access the event stream).

As pattern may be processed by regcomp(3), it should be a non-empty string. Use . (dot) for a “match all” pattern 🔍

  • -X, --timestamp — When replaying from an archive, this option requests that the timestamp be reported with additional date information and increased precision (microseconds with a single -X, nanoseconds with an additional -X), for example Sat May 22 20:32:20.971633 2021 instead of the default format, for example 20:32:20.971 ⏳
  • -z, --hostzone — Use the local timezone of the host that is the source of the performance metrics, as identified by either the -h or the -a or the -U options. The default is to use the timezone of the local host 🌍
  • -Z timezone, --timezone=timezone — Use timezone for the date and time. Timezone is in the format of the environment variable TZ as described in environ(7) 🕰️
  • -?, --help — Display usage message and exit. the classic cry for help, but make it helpful 🥹

💅 CAVEATS 💅

Okay so by default, pmval attempts to display non-integer numeric values in a way that does not distort the inherent precision (rarely more than 4 significant digits), and it tries to maintain a tabular format in the output. But these two goals? They're sometimes in conflict. It's giving two besties fighting over the aux cord. 💀

In the absence of the -f option (described above, you know the one), the following formats are used for different ranges of numeric values for any metric that is of type PM_TYPE_FLOAT or PM_TYPE_DOUBLE, or any metric that has the semantics of a counter (for which pmval reports the rate converted value):

  • Format: ! — Value Range: No values available
  • Format: 9.999E-99 — Value Range: < 0.1
  • Format: 0.0 — Value Range: 0
  • Format: 9.9999 — Value Range: > 0 and <= 0.9999
  • Format: 9.999 — Value Range: > 0.9999 and < 9.999
  • Format: 99.99 — Value Range: > 9.999 and < 99.99
  • Format: 999.9 — Value Range: > 99.99 and < 999.9
  • Format: 9999. — Value Range: > 999.9 and < 9999
  • Format: 9.999E+99 — Value Range: > 9999

🌈 PCP ENVIRONMENT 🌈

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).

For environment variables affecting PCP tools, see pmGetOptions(3).

🫶 DEBUGGING OPTIONS 🫶

The -D or --debug option enables the output of additional diagnostics on stderr to help triage problems, although ngl, the information is sometimes cryptic and primarily intended to provide guidance for developers rather than for end-users. debug is a comma separated list of debugging options; use pmdbg(1) with the -l option to obtain a list of the available debugging options and their meaning.

Debugging options specific to pmval are as follows:

  • appl0 — initial timeline positioning when -a used

👑 SEE ALSO 👑

This page is brought to you by Performance Co-Pilot, PCP, and it's PMVAL(1). That's the footer, bestie — slay, periodt. 💖✨

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