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
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
The pmdanetcheck PMDA reads module-specific
configuration for each module listed in the comma-
separated list of modules (mandatory).
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
align_interval (True) *align_interval (optional) specifies whether to take
the previous check duration into account when pausing
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 parenthesis):
timeout (1) Force a hard timeout (optional) for each individual
network check operation.
debug (False) Enable logging of internal debug messages (rarely
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
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 pcp.conf(5).
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
2020-06-09. (At that time, the date of the most recent commit that
was found in the repository was 2020-06-09.) 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)