PMDAAPACHE(1)

💖 PMDAAPACHE 💖

okay so bestie, listen — this is the manual page for pmdaapache, aka the Apache2 web server performance metrics domain agent (PMDA), from the General Commands Manual. it's giving sysadmin excellence, no cap. 🦋

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✨ SYNOPSIS ✨

$PCP_PMDAS_DIR/apache/pmdaapache [-D debug] [-d domain] [-l logfile] [-U
username] [-S server] [-P port] [-L location]

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🌸 DESCRIPTION 🌸

so pmdaapache is a Performance Metrics Domain Agent (PMDA) that pulls out performance metrics describing the state of an Apache web server. literally its whole job. 💅

the apache PMDA exports metrics that measure the request rate, cumulative request sizes, uptime and various connection states for active clients. obsessed with the range honestly.

this info is obtained by performing a HTTP request to the server status URL, which must be enabled in the httpd.conf configuration file. like, mandatory bestie, no status page = no metrics. 🙈

ExtendedStatus on
<Location /server-status>
SetHandler server-status
Order deny,allow
Deny from all
Allow from localhost
</Location>

and here's a brief description of the pmdaapache command line options, because we're thorough in this house:

• -d — the performance metrics domain number. it is absolutely crucial that the domain number specified here is unique and consistent. meaning: 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. do not fumble this one, i'm so serious. 👑
• -l — location of the log file. by default, a log file named apache.log is written in the current directory of pmcd(1) when pmdaapache is started, i.e. $PCP_LOG_DIR/pmcd. if the log file cannot be created or is not writable, output is written to the standard error instead. slay, graceful degradation. ✨
• -S — query the Apache status information from the named server rather than the local host.
• -P — query the Apache status information from the given port rather than the default (80).
• -L — specify an alternative location for finding the server-status page.
• -U — 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 fr fr. 🌈

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🎀 INSTALLATION 🎀

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

# cd $PCP_PMDAS_DIR/apache
# ./Install

if you want to undo the installation, do the following as root:

# cd $PCP_PMDAS_DIR/apache
# ./Remove

pmdaapache is launched by pmcd(1) and should never be executed directly. the Install and Remove scripts notify pmcd(1) when the agent is installed or removed. so don't be a main character and run it yourself, the system handles it. 💅

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🦋 FILES 🦋

• $PCP_PMCDCONF_PATH — command line options used to launch pmdaapache
• $PCP_PMDAS_DIR/apache/help — default help text file for the apache metrics
• $PCP_PMDAS_DIR/apache/Install — installation script for the pmdaapache agent
• $PCP_PMDAS_DIR/apache/Remove — undo installation script for the pmdaapache agent
• $PCP_LOG_DIR/pmcd/apache.log — default log file for error messages and other information from pmdaapache

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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). iykyk. 🌸

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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. 💀

debugging options specific to pmdaapache are as follows:

• appl0 — trace each refreshData() call
• appl1 — report badness detected in refreshData()
• appl2 — dump internal data after each refreshData() call

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⭐ SEE ALSO ⭐

PCPIntro(1), httpd(8), pmcd(1), pcp.conf(5) and pcp.env(5).

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and that's the whole page bestie!! 🫶 this one's brought to you by Performance Co-Pilot (the PCP girlies 🌟) — PMDAAPACHE(1), periodt 💖✨🎀