Grafana Cloud

TCP checks

A TCP check connects to an endpoint on a given hostname or IP address and a port. This ensures a server accepts the connection and measures response latency and uptime.


TCP checks have the following additional settings:

Option nameDescription
Use TLSWhether or not TLS is used when the connection is initiated.
Query and responseThe response to expect and the data to send.
Disable target certificate validationWhether to validate the certificate that is presented.
Server nameThe server name used during certificate validation.
CA certificateThe certificate for the certificate authority.
Client certificateThe client certificate to present during authentication.
Client keyThe corresponding key for the client certificate.
IP versionThe internet protocol version to use (V4, V6, or any).

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


Metric nameDescription
probe_all_duration_secondsReturns how long the probe took to complete in seconds (histogram).
probe_all_successDisplays whether or not the probe was a success (summary).
probe_dns_lookup_time_secondsReturns the time taken for probe DNS lookup in seconds.
probe_duration_secondsReturns how long the probe took to complete in seconds.
probe_failed_due_to_regexIndicates if probe failed due to regular expression.
probe_ip_addr_hashSpecifies the hash of the IP address. It’s useful to detect if the IP address changes.
probe_ip_protocolSpecifies whether the probe IP protocol is IP4 or IP6.
probe_ssl_earliest_cert_expiryReturns last SSL chain expiry in Unix time.
probe_ssl_last_chain_expiry_timestamp_secondsReturns last SSL chain expiry in timestamp.
probe_ssl_last_chain_infoContains SSL leaf certificate information.
probe_successDisplays whether or not the probe was a success.
probe_tls_version_infoReturns the TLS version used or NaN when unknown.
sm_check_infoProvides information about a single check configuration.