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CoreDNS

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.

Setup

Prerequisites

No action required.

Configuration

File

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

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.

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.

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

Basic HTTP auth

Local server with basic HTTP authentication.

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.

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

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

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.

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

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