pmdanetcheck is a Performance Co-Pilot (PCP) Performance Metrics
Domain Agent (PMDA) which does basic network checks on the local
host by using simple Python modules and, in some cases, external
utilities such as ping(1).
pmdanetcheck loads and acts as a bridge for any number of
configured, separate PCP netcheck PMDA Python modules running
Python code or external programs. Existing Python modules and
programs should be possible to be utilized with PCP netcheck PMDA
modules with minimal effort.
Note that on SELinux enabled systems for pmdanetcheck to be able
to use the ping(1) command the pcp group must be able to create
ICMP Echo sockets; please make sure the group id for pcp is
included in the range at /proc/sys/net/ipv4/ping_group_range and
refer to icmp(7) for more details on this.
pmdanetcheck reads a mandatory ini-style configuration file:
This file must contain a [pmda] section. The following PMDA
options are available (their default values are shown in
parenthesis), options marked with asterisk (*) can be overridden
in module-specific configuration sections:
The pmdanetcheck PMDA reads module-specific configuration
for each module listed in the comma-separated list of
hosts (DGW,DNS) *
A comma-separated list of hosts (optional) specifies the
hosts to run the checks for. The special values DGW, DNS,
NTP will be translated to the default gateway, nameservers
listed in /etc/resolv.conf, and timeservers listed in
/etc/chrony.conf, respectively, on PMDA startup.
background_check (True) *
A boolean value for background_check (optional) controls
whether to run checks constantly in the background or only
on demand. Refer to the default configuration file for
more discussion about this.
check_hosts_parallel (True) *check_hosts_parallel (optional) controls whether modules
should check hosts one by one or in parallel.
check_interval (1m) *check_interval (optional) specifies the time interval
between two consecutive checks for hosts when checks are
done in the background. Refer to PCPIntro(1) for a
complete description of the syntax for the time interval.
align_interval (True) *align_interval (optional) specifies whether to take the
previous check duration into account when pausing between
A boolean value for module_failure_fatal (optional)
controls whether a module failing to initialize should
cause the whole PMDA to abort (this is the default) or to
start up with possibly remaining functional modules.
Module configuration errors and internal errors (such as
failing to register the provided PMNS metrics, see
pmns(5)) will always cause the PMDA to fail to start.
For each module listed in modules a corresponding [module]
section must be defined. Each [module] section can contain at
least the following options (their default values are shown in
Force a hard timeout (optional) for each individual
network check operation.
Enable logging of internal debug messages (rarely used).
The module-specific options modules accept are described in the
default configuration file.
Modules expect basic network functionality to be present on the
system, for example the localhost address being reachable.
To install, the following must be done as root:
# cd $PCP_PMDAS_DIR/netcheck# ./Install
To uninstall, the following must be done as root:
# cd $PCP_PMDAS_DIR/netcheck# ./Removepmdanetcheck 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.
In case module_failure_fatal is set to False, the PMDA
installation will be considered successful if some (but not all)
configured modules fail to load, in such cases metrics provided
by the failing modules will not be available. The pmdanetcheck
agent log file (see below) will contain detailed information
about activation of each module.
Modules will provide real values only after having collected
data. For example, for the ping module the metric value is the
exit value of the ping(1) command and for ping_latency the
average packet latency as reported by ping(1). For metrics
indicating status, 0 denotes success. In case a check has not
finished yet its metric value is -1. If a check was terminated
during execution due to timeout the value is -2.
configuration file for the pmdanetcheck agent
PCP netcheck PMDA Python modules for the pmdanetcheck agent
installation script for the pmdanetcheck agent
undo installation script for the pmdanetcheck agent
default log file for messages from the pmdanetcheck agent
Note that the usual/default value for $PCP_PMDAS_DIR is
/var/lib/pcp/pmdas and the default for $PCP_LOG_DIR is
/var/log/pcp but these settings are platform dependent.
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
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at
⟨http://www.pcp.io/⟩. If you have a bug report for this manual
page, send it to firstname.lastname@example.org. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2021-08-27.
(At that time, the date of the most recent commit that was found
in the repository was 2021-08-27.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
Performance Co-Pilot PCP PMDANETCHECK(1)