librenms-librenms/includes/datastore.inc.php

<?php
/*
 * LibreNMS abstract data storage interface to both rrdtool & influxdb
 *
 * Copyright (c) 2016 Paul D. Gear <paul@librenms.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

require_once $config['install_dir'] . "/includes/rrdtool.inc.php";
require_once $config['install_dir'] . "/includes/influxdb.inc.php";


/**
 * Filter all elements with keys that start with 'rrd_'
 *
 * @param array $arr input array
 * @return array Copy of $arr with all keys beginning with 'rrd_' removed.
 */
function rrd_array_filter($arr)
{
    $result = array();
    foreach ($arr as $k => $v) {
        if (strpos($k, 'rrd_') === 0) {
            continue;
        }
        $result[$k] = $v;
    }
    return $result;
} // rrd_array_filter


/**
 * Datastore-independent function which should be used for all polled metrics.
 *
 * RRD Tags:
 *   rrd_def     array|string: (required) an array of rrd field definitions example: "DS:dataName:COUNTER:600:U:100000000000"
 *   rrd_name    array|string: the rrd filename, will be processed with rrd_name()
 *   rrd_oldname array|string: old rrd filename to rename, will be processed with rrd_name()
 *   rrd_step             int: rrd step, defaults to 300
 *
 * @param array $device
 * @param string $measurement Name of this measurement
 * @param array $tags tags for the data (or to control rrdtool)
 * @param array $fields
 */
function data_update($device, $measurement, $tags, $fields)
{
    // convenience conversion to allow calling with a single value, so, e.g., these are equivalent:
    // data_update($device, 'mymeasurement', $tags, 1234);
    //     AND
    // data_update($device, 'mymeasurement', $tags, array('mymeasurement' => 1234));
    if (!is_array($fields)) {
        $fields = array($measurement => $fields);
    }

    // rrdtool_data_update() will only use the tags it deems relevant, so we pass all of them.
    // However, influxdb saves all tags, so we filter out the ones beginning with 'rrd_'.

    rrdtool_data_update($device, $measurement, $tags, $fields);
    influx_update($device, $measurement, rrd_array_filter($tags), $fields);
} // data_update