CoreDNS

Plugin: go.d.plugin Module: coredns

Overview

This collector monitors CoreDNS instances.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior

Auto-Detection

This integration doesn't support auto-detection.

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

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.

Per CoreDNS instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
coredns.dns_request_count_total	requests	requests/s
coredns.dns_responses_count_total	responses	responses/s
coredns.dns_request_count_total_per_status	processed, dropped	requests/s
coredns.dns_no_matching_zone_dropped_total	dropped	requests/s
coredns.dns_panic_count_total	panics	panics/s
coredns.dns_requests_count_total_per_proto	udp, tcp	requests/s
coredns.dns_requests_count_total_per_ip_family	v4, v6	requests/s
coredns.dns_requests_count_total_per_per_type	a, aaaa, mx, soa, cname, ptr, txt, ns, ds, dnskey, rrsig, nsec, nsec3, ixfr, any, other	requests/s
coredns.dns_responses_count_total_per_rcode	noerror, formerr, servfail, nxdomain, notimp, refused, yxdomain, yxrrset, nxrrset, notauth, notzone, badsig, badkey, badtime, badmode, badname, badalg, badtrunc, badcookie, other	responses/s

Per server

These metrics refer to the DNS server.

Labels:

Label	Description
server_name	Server name.

Metrics:

Metric	Dimensions	Unit
coredns.server_dns_request_count_total	requests	requests/s
coredns.server_dns_responses_count_total	responses	responses/s
coredns.server_request_count_total_per_status	processed, dropped	requests/s
coredns.server_requests_count_total_per_proto	udp, tcp	requests/s
coredns.server_requests_count_total_per_ip_family	v4, v6	requests/s
coredns.server_requests_count_total_per_per_type	a, aaaa, mx, soa, cname, ptr, txt, ns, ds, dnskey, rrsig, nsec, nsec3, ixfr, any, other	requests/s
coredns.server_responses_count_total_per_rcode	noerror, formerr, servfail, nxdomain, notimp, refused, yxdomain, yxrrset, nxrrset, notauth, notzone, badsig, badkey, badtime, badmode, badname, badalg, badtrunc, badcookie, other	responses/s

Per zone

These metrics refer to the DNS zone.

Labels:

Label	Description
zone_name	Zone name.

Metrics:

Metric	Dimensions	Unit
coredns.zone_dns_request_count_total	requests	requests/s
coredns.zone_dns_responses_count_total	responses	responses/s
coredns.zone_requests_count_total_per_proto	udp, tcp	requests/s
coredns.zone_requests_count_total_per_ip_family	v4, v6	requests/s
coredns.zone_requests_count_total_per_per_type	a, aaaa, mx, soa, cname, ptr, txt, ns, ds, dnskey, rrsig, nsec, nsec3, ixfr, any, other	requests/s
coredns.zone_responses_count_total_per_rcode	noerror, formerr, servfail, nxdomain, notimp, refused, yxdomain, yxrrset, nxrrset, notauth, notzone, badsig, badkey, badtime, badmode, badname, badalg, badtrunc, badcookie, other	responses/s

Alerts

There are no alerts configured by default for this integration.

Setup

Prerequisites

No action required.

Configuration

File

The configuration file name for this integration is go.d/coredns.conf.

The file format is YAML. Generally, the structure 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/coredns.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	no
autodetection_retry	Recheck interval in seconds. Zero means no recheck will be scheduled.	0	no
url	Server URL.	http://127.0.0.1:9153/metrics	yes
per_server_stats	Server filter.		no
per_zone_stats	Zone filter.		no
username	Username for basic HTTP authentication.		no
password	Password for basic HTTP authentication.		no
proxy_url	Proxy URL.		no
proxy_username	Username for proxy basic HTTP authentication.		no
proxy_password	Password for proxy basic HTTP authentication.		no
timeout	HTTP request timeout.	2	no
method	HTTP request method.	GET	no
body	HTTP request body.		no
headers	HTTP request headers.		no
not_follow_redirects	Redirect handling policy. Controls whether the client follows redirects.	no	no
tls_skip_verify	Server certificate chain and hostname validation policy. Controls whether the client performs this check.	no	no
tls_ca	Certification authority that the client uses when verifying the server's certificates.		no
tls_cert	Client tls certificate.		no
tls_key	Client tls key.		no

per_server_stats

Metrics of servers matching the selector will be collected.

• Logic: (pattern1 OR pattern2) AND !(pattern3 or pattern4)
• Pattern syntax: matcher.
• Syntax:

per_server_stats:
  includes:
    - pattern1
    - pattern2
  excludes:
    - pattern3
    - pattern4

per_zone_stats

Metrics of zones matching the selector will be collected.

• Logic: (pattern1 OR pattern2) AND !(pattern3 or pattern4)
• Pattern syntax: matcher.
• Syntax:

per_zone_stats:
  includes:
    - pattern1
    - pattern2
  excludes:
    - pattern3
    - pattern4

Examples

Basic

An example configuration.

Config

jobs:
  - name: local
    url: http://127.0.0.1:9153/metrics

Basic HTTP auth

Local server with basic HTTP authentication.

Config

jobs:
  - name: local
    url: http://127.0.0.1:9153/metrics
    username: foo
    password: bar

Multi-instance

Note: When you define multiple jobs, their names must be unique.

Collecting metrics from local and remote instances.

Config

jobs:
  - name: local
    url: http://127.0.0.1:9153/metrics

  - name: remote
    url: http://203.0.113.10:9153/metrics

Troubleshooting

Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the coredns 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 coredns

Getting Logs

If you're encountering problems with the coredns collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep coredns

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector's name:

grep coredns /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named "netdata" (replace if different), use this command:

docker logs netdata 2>&1 | grep coredns