PMDASUMMARY(1)

💖 PMDASUMMARY 💖

okay bestie, so this is the manual page for pmdasummary, from section 1 of the General Commands Manual — aka the summary performance metrics domain agent (PMDA). yes that's a mouthful, we'll get through it together 🫶

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✨ SYNOPSIS ✨

$PCP_PMDAS_DIR/summary/pmdasummary [-D debug] [-d domain] [-h helpfile]
[-l logfile] [-U username] pmie-command-line

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🌸 DESCRIPTION 🌸

pmdasummary is a Performance Metrics Domain Agent (PMDA) — and no, it doesn't measure stuff itself, it's giving derived energy 💅. It takes values that other PMDAs already made available and computes new performance metric values out of them.

It's literally two processes living their best lives together:

• pmie process — the inference engine for performance values, pmie(1), is used to periodically sample values for the base metrics and compute the derived values. This process gets launched with the pmie-command-line arguments you pass in, by the main process (described right below, bestie, don't worry).
• main process — the main process reads and buffers the values computed by pmie(1) and makes them available to the performance metrics collector daemon pmcd(1). it's the middleman and honestly it's thriving ✨

so here's a quick rundown of the pmdasummary command line options:

• -d — this one is absolutely crucial, no cap. The performance metrics domain number you specify here has to be unique and consistent. Like, domain should be different for every PMDA on the one host, and the same domain number should be used for the same PMDA on all hosts. don't mess with this one, fr fr 🙈
• -h — specifies an alternative help text file, helpfile, for describing the metrics that pmdasummary represents.
• -l — where the log file lives. By default, a log file named summary.log is written in the current directory of pmcd(1) when pmdasummary is started, i.e. $PCP_LOG_DIR/pmcd. And if the log file cannot be created or is not writable? output goes to the standard error instead. the fallback queen 💅
• -U — the user account under which to run the agent. The default is the unprivileged "pcp" account in current versions of PCP, but in older versions the superuser account ("root") was used by default. glow-up behavior honestly 🌈

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🎀 INSTALLATION 🎀

If you want access to the names, help text and values for the summary performance metrics, do the following as root:

# cd $PCP_PMDAS_DIR/summary
# ./Install

And if you want to undo the installation (we've all been there, no shame), do the following as root:

# cd $PCP_PMDAS_DIR/summary
# ./Remove

important vibe check: pmdasummary is launched by pmcd(1) and should never be executed directly. do not come for it. The Install and Remove scripts notify pmcd(1) when the agent is installed or removed, so they handle the whole situationship for you 🫶

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🦋 FILES 🦋

• $PCP_PMCDCONF_PATH — command line options used to launch pmdasummary
• $PCP_PMDAS_DIR/summary/expr.pmie — default pmie(1) expressions defining the summary metrics
• $PCP_PMDAS_DIR/summary/help — default help text for the summary metrics
• $PCP_PMDAS_DIR/summary/Install — installation script for the pmdasummary agent
• $PCP_PMDAS_DIR/summary/Remove — undo installation script for the pmdasummary agent
• $PCP_LOG_DIR/pmcd/summary.log — default log file for error messages and other information from pmdasummary

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🌈 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). it's giving configuration inception 💜

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💀 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. iykyk 😭

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⭐ SEE ALSO ⭐

PCPIntro(1), pmcd(1) and pmie(1).

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and that's the whole page, bestie!! go forth and summarize some metrics, you absolute icon 👑✨

Performance Co-Pilot — PCP — PMDASUMMARY(1) 🦋 mwah, drink water, and remember: never run it directly 💖