Unbound monitoring with Netdata

Unbound is a validating, recursive, and caching DNS resolver product from NLnet Labs.

This module monitors one or more Unbound servers, depending on your configuration.

Requirements

• Unbound with enabled remote-control interface ( see unbound.conf)

If using unix socket:

• socket should be readable and writeable by netdata user

If using ip socket and TLS is disabled:

• socket should be accessible via network

If TLS is enabled, in addition:

• control-key-file should be readable by netdata user
• control-cert-file should be readable by netdata user

For auto detection parameters from unbound.conf:

• unbound.conf should be readable by netdata user
• if you have several configuration files (include feature) all of them should be readable by netdata user

Charts

Module produces following summary charts:

• Received Queries in queries
• Rate Limited Queries in queries
• DNSCrypt Queries in queries
• Cache Statistics in events
• Cache Statistics Percentage in percentage
• Cache Prefetches in prefetches
• Replies Served From Expired Cache in replies
• Replies That Needed Recursive Processing in replies
• Time Spent On Recursive Processing in milliseconds
• Request List Usage in queries
• Current Request List Usage in queries
• Request List Jostle List Events in queries
• TCP Handler Buffers in buffers
• Uptime seconds

If extended-statistics is enabled:

• Queries By Type in queries
• Queries By Class in queries
• Queries By OpCode in queries
• Queries By Flag in queries
• Replies By RCode in replies
• Cache Items Count in items
• Cache Memory in KB
• Module Memory in KB
• TCP and TLS Stream Wait Buffer Memory in KB

Per thread charts (only if number of threads > 1):

• Received Queries in queries
• Rate Limited Queries in queries
• DNSCrypt Queries in queries
• Cache Statistics in events
• Cache Statistics Percentage in events
• Cache Prefetches in prefetches
• Replies Served From Expired Cache in replies
• Replies That Needed Recursive Processing in replies
• Time Spent On Recursive Processing in milliseconds
• Request List Usage in queries
• Current Request List Usage in queries
• Request List Jostle List Events in queries
• TCP Handler Buffers in buffers

Configuration

Edit the go.d/unbound.conf configuration file using edit-config from the Netdata config directory, which is typically at /etc/netdata.

cd /etc/netdata # Replace this path with your Netdata config directory
sudo ./edit-config go.d/unbound.conf

This Unbound collector only needs the address to a server's remote-control interface if TLS is disabled or address of unix socket. Otherwise you need to set path to the control-key-file and control-cert-file files.

The module tries to auto-detect following parameters reading unbound.conf:

• address
• cumulative_stats
• use_tls
• tls_cert
• tls_key

Module supports both cumulative and non-cumulative modes. Default is non-cumulative. If your server has enabled statistics-cumulative, but the module fails to auto-detect it (unbound.conf is not readable or it is a remote server), you need to set it manually in the configuration file.

Here is an example for several servers:

jobs:
  - name: local
    address: 127.0.0.1:8953
    use_tls: yes
    tls_skip_verify: yes
    tls_cert: /etc/unbound/unbound_control.pem
    tls_key: /etc/unbound/unbound_control.key

  - name: remote
    address: 203.0.113.10:8953
    use_tls: no

  - name: remote_cumulative
    address: 203.0.113.11:8953
    use_tls: no
    cumulative_stats: yes

  - name: socket
    address: /var/run/unbound.sock

For all available options, please see the module configuration file.

Troubleshooting

Ensure that the control protocol is actually configured correctly. Run following command as root user:

unbound-control stats_noreset

It should print out a bunch of info about the internal statistics of the server. If this returns an error, you don't have the control protocol set up correctly.

To troubleshoot issues with the unbound 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.

First, navigate to your plugins directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the setting plugins directory. Once you're in the plugin's directory, switch to the netdata user.

cd /usr/libexec/netdata/plugins.d/
sudo -u netdata -s

You can now run the go.d.plugin to debug the collector:

./go.d.plugin -d -m unbound