Dnsmasq collector

Overview

Dnsmasq is a lightweight, easy to configure DNS forwarder, designed to provide DNS (and optionally DHCP and TFTP) services to a small-scale network.

This collector monitors one or more Dnsmasq DNS Forwarder instances, depending on your configuration.

It collects DNS cache statistics by reading the response on the following query:

;; opcode: QUERY, status: NOERROR, id: 37862
;; flags: rd; QUERY: 7, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;cachesize.bind.   CH  TXT
;insertions.bind.  CH  TXT
;evictions.bind.   CH  TXT
;hits.bind.        CH  TXT
;misses.bind.      CH  TXT
;servers.bind.     CH  TXT

Collected metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

global

The metrics apply to the entire monitored application.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
dnsmasq.servers_queries	success, failed	queries/s
dnsmasq.cache_performance	hist, misses	events/s
dnsmasq.cache_operations	insertions, evictions	operations/s
dnsmasq.cache_size	size	entries

Setup

Prerequisites

No action required.

Configuration

File

The configuration file name is go.d/dnsmasq.conf.

The file format is YAML. Generally, the format is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name1

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/dnsmasq.conf

Options

The following options can be defined globally: update_every, autodetection_retry.

All options

Name	Description	Default	Required
update_every	Data collection frequency.	1
autodetection_retry	Re-check interval in seconds. Zero means not to schedule re-check.	0
address	Server's address. Format is 'ip_address:port'.	127.0.0.1:53	yes
protocol	DNS query transport protocol. Valid options: udp, tcp, tcp-tls.	-
timeout	DNS query timeout (dial, write and read) in seconds.	1

Examples

Basic

An example configuration.

jobs:
  - name: local
    address: '127.0.0.1:53'

Basic example with protocol option

Local server with defined DNS query transport protocol.

jobs:
  - name: local
    address: '127.0.0.1:53'
    protocol: udp

Multi-instance

When you are defining more than one jobs, you must be careful to use different job names, to not override each other.

jobs:
  - name: local
    address: '127.0.0.1:53'

  - name: remote
    address: '203.0.113.0:53'

Troubleshooting

Debug mode

To troubleshoot issues with the dnsmasq collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn't working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/

• Switch to the netdata user.

  sudo -u netdata -s

• Run the go.d.plugin to debug the collector:

  ./go.d.plugin -d -m dnsmasq