URL
HTTP response
Check status, timeout, redirect handling, and response observations.
Sentinel / website foundations
Know when the foundations move.
A server can answer while the website promise underneath it changes. Sentinel watches HTTP, certificates, domains, DNS, email infrastructure, redirects, and the history needed to diagnose the difference.
CONCEPTUAL OBSERVATIONEXPECTED / OBSERVED
HTTP response200 OK200 OK
Redirect targethttps://site.tldhttps://old.tld
Certificate expiry> 30 days12 days
Incident stateclosedopen
Illustrative example, not a product screenshot. Actual observations depend on the target and configuration.
Beyond a basic uptime answer
Ask whether the promise still holds.
A response is the beginning of the diagnosis.
Basic uptime answersSentinel also answers
Did the server respond?Did it respond with the right status and redirect?
Is TLS currently valid?Is the certificate or chain approaching a problem?
Did DNS resolve?Did the address, nameserver, mail, or CDN fingerprint change?
Is the page reachable?Can the operator explain the run history and recovery?
HTTP and response monitoring
Start with the response. Then keep the context.
Set an expected status, timeout, and redirect policy for monitored URLs. Sentinel records observations over time so a changed response can be understood alongside recovery and related incidents.
SSL and domain
See the trust signal before it becomes an interruption.
Observe certificate expiry windows, chain and hostname details, protocol floor, issuer changes, and domain expiry. Sentinel reports these conditions; it does not renew certificates or domains for you.
SITE
SSL certificate and chain
Observe certificate expiry, chain, hostname, protocol, and issuer changes.
SITE
Domain expiry
Know when a domain registration window is approaching.
DNS and mail infrastructure
Make quiet infrastructure changes visible.
Keep nameserver, A/AAAA, MX, DNSSEC, SPF, DKIM, and DMARC observations in the same monitoring history. CDN fingerprinting can highlight a provider change where the response and DNS evidence support it.
SITE
Nameserver changes
Know when authoritative nameservers change.
SITE
A/AAAA record changes
Notice address-record changes and unexpected target movement.
SITE
MX record changes
Keep mail-exchanger changes visible alongside site changes.
SITE
DNSSEC chain
Check whether DNSSEC chain-of-trust validation passes.
SITE
SPF record
Observe SPF policy and lookup constraints.
SITEConditional
DKIM selectors
Check configured DKIM selectors for key presence and format.
SITE
DMARC policy
Observe the domain DMARC policy and its configured strength.
SITEConditional
CDN provider fingerprint
Notice a change in the provider inferred from headers and DNS.
SITEPro
Malware or blocklist provider
Check a configured external provider for a reported malware or blocklist signal.
Redirect policy
Check where the visitor actually lands.
Assert HTTP-to-HTTPS, www/non-www, missing-page, and configured regional redirect behaviour. Regional checks depend on an appropriate proxy supplied and operated by the customer; Sentinel is not a built-in global probe network.
URL
HTTP to HTTPS redirect
Check that HTTP resolves to the intended HTTPS target.
URL
Canonical www redirect
Check the configured www or non-www host policy.
URL
404 page response
Check the response and expected content of a missing-page route.
URLConditional
Regional redirect policy
Assert a configured regional redirect from the perspective of an operator-supplied route.
Operational history
Keep the failure, the incident, and the recovery together.
Runs become the evidence behind a contiguous incident. Severity, acknowledgement, recovery, maintenance windows, quiet hours, digests, and monthly summaries give the operator a place to understand expected versus unexpected change.
URL
HTTP response
Check status, timeout, redirect handling, and response observations.
SITE
SSL certificate and chain
Observe certificate expiry, chain, hostname, protocol, and issuer changes.
Request control
Check from the context your site expects.
Configure user-agent, additional headers, text or JavaScript mode, and operator-supplied proxy profiles. Credentials and proxy secrets remain configuration responsibilities; the brochure does not expose them.
URL
HTTP response
Check status, timeout, redirect handling, and response observations.
URL
HTTP security headers
Observe selected response-security headers and field-level changes.
Read the qualifier
The useful caveat is part of the feature.
Sentinel observes certificate and domain conditions; it does not renew either asset or repair the site.
Provider-backed malware checks require Pro and a configured external provider. They are not a universal malware-removal service.
Regional redirect checks use the proxy and route supplied by the operator. They do not imply a built-in global probe fleet.
“As often as every minute on Pro” is a cadence floor where the individual check permits it, not a detection-time guarantee.
Continue the build
Pair infrastructure checks with page-level context.
Canonical Sentinel brochure pages.