PMDAPROMETHEUS

Section: User Commands (1)
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NAME

pmdaprometheus - Prometheus PMDA

DESCRIPTION

pmdaprometheus is a Performance Metrics Domain Agent (PMDA) which creates PCP metrics from Prometheus endpoints, which provide HTTP based access to application metrics.

Further details on the Prometheus exposition format can be found at https://prometheus.io/docs/instrumenting/exposition_formats

METADATA SOURCES

pmdaprometheus scans the $PCP_PMDAS_DIR/prometheus/metadata directory, looking for metadata files ( *.json). These JSON metadata files describe the names, types, etc. of their associated Prometheus metrics for a given endpoint. For example, let's assume the following simple Prometheus metric:

              # HELP go_goroutines Number of goroutines that currently exist.
              # TYPE go_goroutines gauge
              go_goroutines 86

The associated metadata file would look like the following:

              {
                "metrics": [
                  {
                    "semantics": "instantaneous",
                    "type": "uint64",
                    "units_str": "",
                    "prometheus_name": "go_goroutines",
                    "name": "go_goroutines",
                    "description": "Number of goroutines that currently exist."
                  }
                ]
              }

Allowable values for each of the metadata fields are:

semantics =[counter, instantaneous]/: the semantics of the metric
type =[double, uint64]/: the base data type of the metric
name = ,STRING/: name of the metric to be used in PCP
units_str = ,STRING/: the dimension and units of the metric which can be parsed by pmParseUnitsStr (3)
prometheus_name = ,STRING/: complete metric name as used in Prometheus
description = ,STRING/: text description of the metric

METADATA GENERATOR

The pmdaprometheus metadata generation helper script helps in providing initial content for the (heuristic-based) metric metadata, from a Prometheus endpoint.

$PCP_PMDAS_DIR/prometheus/Generate [ ,OPTIONS]

Mandatory arguments to long options are mandatory for short options too. Following are the mandatory options:

-u , --url = ,STRING/: URL of the Prometheus endpoint
-n , --name = ,STRING/: name of the Prometheus endpoint

INSTALLATION

Install the Prometheus PMDA by using the Install script as root:

# cd $PCP_PMDAS_DIR/prometheus

# ./Install

To uninstall, do the following as root:

# cd $PCP_PMDAS_DIR/prometheus

# ./Remove

pmdaprometheus 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.

FILES

$PCP_PMDAS_DIR/prometheus/Install: installation script for the pmdaprometheus agent
$PCP_PMDAS_DIR/prometheus/Remove: undo installation script for the pmdaprometheus agent
$PCP_PMDAS_DIR/prometheus/Generate: generate metadata describing available metrics based on heuristics
$PCP_PMDAS_DIR/prometheus/metadata/: metadata files for the pmdaprometheus agent
$PCP_LOG_DIR/pmcd/prometheus.log: default log file for error messages from pmdaprometheus

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).