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Exporting Metrics to InfluxDB via the collectd Network Plugin

This document provides an example of using the Network plugin to export metrics to the InfluxDB temporal database. It will also demonstrate how to visualize the metrics collected in InfluxDB using Grafana.

Example Workflow

Example of metric

This example shows how to work with the single wallarm_nginx/gauge-abnormal metric, which shows the number of requests processed by the filter node.

Example Workflow

The following deployment scheme is used in this document:

  • The Wallarm filter node is deployed on a host accessible via the 10.0.30.5 IP address and the node.example.local fully qualified domain name.

    The network plugin for collectd on the filter node is configured in such a way that all metrics will be sent to the 10.0.30.30 InfluxDB server on port 25826/UDP.

    Network plugin features

    Please note that the plugin operates over UDP (see using examples and documentation of the network plugin).

  • Both influxdb and grafana services are deployed as Docker containers on a separate host with the 10.0.30.30 IP address.

    The influxdb service with the InfluxDB database is configured as follows:

    • A collectd data source has been created (the collectd input according to InfluxDB terminology), which listens on the 25826/UDP port and writes incoming metrics to a database called collectd.
    • Communication with the InfluxDB API occurs via the 8086/TCP port.
    • The service shares a sample-net Docker network with the grafana service.

    The grafana service with Grafana is configured as follows:

    • The Grafana web console is available at http://10.0.30.30:3000.
    • The service shares the sample-net Docker network with the influxdb service.

Configuring Metrics Export to InfluxDB

Prerequisites

It is assumed that

  • Docker Community Edition and docker-compose are already installed on the 10.0.30.30 Docker host.
  • The node.example.local filter node is already deployed, configured, available for further configuration (for example, via the SSH protocol), and working.

Deploying InfluxDB and Grafana

Deploy InfluxDB and Grafana on the Docker host:

  1. Create a working directory, for example, /tmp/influxdb-grafana, and navigate to it:

    mkdir /tmp/influxdb-grafana
cd /tmp/influxdb-grafana

  2. For the InfluxDB data source to work, you will need a file named types.db that contains the collectd value types.

    This file describes the dataset specifications used by collectd. Such datasets include definitions of measurable types. Detailed information about this file is available here.

    Download the types.db file from the GitHub repository of the collectd project and put it in the working directory.

  3. Get the basic InfluxDB configuration file by running the following command: 

    docker run --rm influxdb influxd config > influxdb.conf

  4. Enable the collectd data source in the influxdb.conf InfluxDB configuration file by changing the value of the enabled parameter in the [[collectd]] section from false to true.

    Leave other parameters unchanged.

    The section should look like this:

    [[collectd]]
  enabled = true
  bind-address = ":25826"
  database = "collectd"
  retention-policy = ""
  batch-size = 5000
  batch-pending = 10
  batch-timeout = "10s"
  read-buffer = 0
  typesdb = "/usr/share/collectd/types.db"
  security-level = "none"
  auth-file = "/etc/collectd/auth_file"
  parse-multivalue-plugin = "split"

  5. Create a docker-compose.yaml file in the working directory with the following content:

    version: "3"

services:
  influxdb:
    image: influxdb
    container_name: influxdb
    ports:
      - 8086:8086
      - 25826:25826/udp
    networks:
      - sample-net
    volumes:
      - ./:/var/lib/influxdb
      - ./influxdb.conf:/etc/influxdb/influxdb.conf:ro
      - ./types.db:/usr/share/collectd/types.db:ro

  grafana:
    image: grafana/grafana
    container_name: grafana
    restart: always
    ports:
      - 3000:3000
    networks:
      - sample-net

networks:
  sample-net:

    According to the settings in volumes:, InfluxDB will use
    1. The working directory as storage for the database.
    2. The influxdb.conf configuration file that is located in the working directory.
    3. The types.db file with the types of measurable values that is located in the working directory.

  6. Build the services by executing the docker-compose build command.

  7. Run the services by executing the docker-compose up -d influxdb grafana command.

  8. Create a database named collectd for the corresponding InfluxDB data source by executing the following command:

    curl -i -X POST http://10.0.30.30:8086/query --data-urlencode "q=CREATE DATABASE collectd"

    The InfluxDB server should return a response similar to:

    HTTP/1.1 200 OK
Content-Type: application/json
Request-Id: 23604241-b086-11e9-8001-0242ac190002
X-Influxdb-Build: OSS
X-Influxdb-Version: 1.7.7
X-Request-Id: 23604241-b086-11e9-8001-0242ac190002
Date: Sat, 27 Jul 2019 15:49:37 GMT
Transfer-Encoding: chunked

{"results":[{"statement_id":0}]}

At this point, InfluxDB should be running, ready to receive metrics from collectd, and Grafana should be ready to monitor and visualize the data stored in InfluxDB.

Configuring collectd

Configure collectd to export metrics to InfluxDB:

  1. Connect to the filter node (for example, by using the SSH protocol). Make sure you are logged in as root or another account with superuser privileges.

  2. Add the following configuration to the /opt/wallarm/etc/collectd/wallarm-collectd.conf file:

    LoadPlugin network

<Plugin "network">
  Server "Server IPv4/v6 address or FQDN" "Server port"
</Plugin>

    The following entities are configured here:

    1. The server, to send metrics to (10.0.30.30)
    2. The port that server listens on (25826/UDP)

  3. Restart the wallarm service by running the following command:

    sudo systemctl restart wallarm
  1. Connect to the filter node (for example, by using the SSH protocol). Make sure you are logged in as root or another account with superuser privileges.

  2. Create a file named /etc/collectd/collectd.conf.d/export-to-influxdb.conf with the following content:

    LoadPlugin network

<Plugin "network">
    Server "10.0.30.30" "25826"
</Plugin>

    The following entities are configured here:

    1. The server, to send metrics to (10.0.30.30)
    2. The port that server listens on (25826/UDP)

  3. Restart the collectd service by running the appropriate command:

    sudo service collectd restart

    sudo systemctl restart collectd

Now InfluxDB receives all the metrics of the filter node. You can visualize the metrics you are interested in and monitor them with Grafana.