DNS check

DNS or domain name servers resolve a domain such as grafana.com to an IP address. This check ensures a domain resolves and measures the average time for the resolution to happen. DNS checks can be set up to validate against a specific DNS server and check for a specific kind of response.

Options

The list of common options to all check types:

Option	Description
Enabled	Whether the check is enabled or not.
Job name	Refer to the check name. Check metrics include a `job` label with the value of this option.
Target	Target of the check request. Check metrics include an `instance` label with the value of this option.
Probe locations	The locations where the check should run from. Check metrics include a `probe` label with the value of the probe location running the check.
Frequency	The frequency the check should run in seconds. The value can range from 60 to 3600 seconds. Only the `sm_check_info` metric includes the `frequency` label.
Timeout	Maximum execution time for the check. The value can range from 1 to 60 seconds.
Custom labels	(Optional) Custom labels applied to check metrics. Refer to Custom labels for querying instructions.

Additionally, DNS checks have the following options:

Option	Description
Record type	The resource record to query.
Server	The nameserver to query.
Port	The port used to connect to the server.
Protocol	The protocol (TCP, UDP) used to connect to the server.
Valid response codes	The set of response codes to accept.
Valid response matches	A series of validations to apply to the response.
IP version	The internet protocol version to use (V4, V6 or any).
Publish full set of metrics	Whether to publish additional metrics to create histograms (used for Apdex scores or heatmaps). Default is false to reduce the number of active series.

These last options don’t produce any additional labels in the resulting check metrics.

Metrics

Checks store their results as Prometheus metrics, including the list of common metrics:

Metric	Description
`probe_all_duration_seconds`	Returns how long the probe took to complete in seconds (histogram).
`probe_duration_seconds`	Returns how long the probe took to complete in seconds.
`probe_all_success`	Displays whether or not the probe was a success (summary).
`probe_success`	Displays whether or not the probe was a success.
`sm_check_info`	Provides information about a single check configuration.

Additionally, DNS checks produce the following metrics:

Metric	Description
`probe_dns_additional_rrs`	Returns the number of entries in the additional resource record list.
`probe_dns_answer_rrs`	Returns the number of entries in the answer resource record list.
`probe_dns_authority_rrs`	Returns the number of entries in the authority resource record list.
`probe_dns_duration_seconds`	Duration of DNS request by phase.
`probe_dns_lookup_time_seconds`	Returns the time taken for probe DNS lookup in seconds.
`probe_dns_query_succeeded`	Displays whether or not the query was executed successfully.
`probe_ip_addr_hash`	Specifies the hash of the IP address. It’s useful to detect if the IP address changes.
`probe_ip_protocol`	Specifies whether probe IP protocol is IP4 or IP6.