openMetrics PMDA (OpenMetrics PMDA)
Описание (Description)
pmdaopenmetrics is a Performance Metrics Domain Agent (PMDA)
which dynamically creates PCP metrics from configured OpenMetrics
endpoints, which provide HTTP based access to application
metrics. The PMDA essentially implements a bridge between
Prometheus and PCP, allowing PCP to easily ingest performance
data from more than 650 registered end-points and many other
application specific end-points.
The default config directory is
$PCP_PMDAS_DIR/openmetrics/config.d/, see ``CONFIGURATION
SOURCES'' below. The default URL fetch timeout is 2 seconds.
The default user, if not specified with the -u option, is the
current user. If the -n option is given, the list of
configuration files will not be sorted prior to processing. This
list is sorted by default but that can be expensive if there are
a large number of configuration files (URLs and/or scripts).
If the -D option is given, additional diagnostic messages will be
written to the PMDA log file, which is
$PCP_LOG_DIR/pmcd/openmetrics.log by default (see also -lbelow).
In addition, the metric openmetrics.control.debug controls the
same debug flag and can be set with the following command:
pmstore openmetrics.control.debug value
where value is either 1 (to enable verbose log messages) or 0 (to
disable verbose log messages). This is particularly useful for
examining the http headers passed to each fetch request, filter
settings and other processing details that are logged when the
debugging flag is enabled.
The -d option may be used to override the default performance
metrics domain number, which defaults to 144. It is strongly
recommended not to change this. The domain number should be
different for every PMDA on the one host, and the same domain
number should be used for pmdaopenmetrics PMDA on all hosts. See
also the -r option, which allows the root of the dynamic
namespace to be changed from the default openmetrics.
The -l option may be used to specify logfile as the destination
for PMDA messages instead of the default,
$PCP_LOG_DIR/pmcd/openmetrics.log. As a special case, logfile
may be "-" to send messages to the stderr stream instead, e.g.
-l-. This would normally be the stderr stream for the parent
process, pmcd(1), which may itself have redirected stderr. This
redirection is normally most useful in a containerized
environment, or when using dbpmda(1).
The -r option allows the root of the dynamic namespace to be
changed to root from the default, openmetrics. In conjunction
with other command line options, this allows pmdaopenmetrics to
be deployed as a different PMDA with distinct metrics namespace
and metrics domain on the same host system. Note that all PMDAs
require a unique domain number so the -d option must also be
specified. Use of the -r option may also change the defaults for
some other command line options, e.g. the default log file name
and the default configuration directory.
