What Is Uptime Monitoring?
Uptime monitoring is the automated checking of a website or service to determine whether it is reachable and responding as expected. It helps detect outages, connection failures, HTTP errors and response problems from outside the monitored infrastructure.
What Does Uptime Monitoring Check?
A typical uptime check makes a request to the monitored website and evaluates whether the connection succeeds, the server responds and the response meets the expected conditions.
What Should an Uptime Monitor Check?
Reachability
The monitor checks whether the hostname can be reached and whether a connection to the service can be established.
HTTP Response
The monitor checks the HTTP response and can detect unexpected status codes or other response failures.
Response Time
The monitor can measure how long the request takes to receive a response. A site may still be technically online while becoming unusually slow.
HTTPS and TLS
For HTTPS sites, the connection also depends on TLS being established successfully. Certificate problems can therefore appear as an availability problem to users.
What Do HTTP Status Codes Mean for Uptime?
HTTP status codes provide useful information about how a request was handled. Successful responses such as 200 indicate that the server processed the request successfully, while 4xx and 5xx responses generally indicate client-side or server-side problems.
200 OK
The exact definition of “up” depends on what the monitor is expected to verify. A custom endpoint may intentionally return a different status, so uptime checks should be evaluated against the expected behaviour of the service.
Why Does Response Time Matter?
Availability is not only a binary question. A website that technically responds but takes an unusually long time to respond can still be effectively unavailable for users. Tracking response time helps reveal performance degradation before it becomes a complete outage.
What About DNS?
A website cannot be reached reliably when its DNS configuration is broken. DNS monitoring and uptime monitoring therefore complement each other: uptime asks whether the service is reachable, while DNS monitoring helps explain changes or failures in the records that lead clients to that service.
How Often Should Uptime Be Checked?
The right interval depends on how quickly an outage needs to be detected. More frequent checks reduce the detection delay, while less frequent checks may be sufficient for services where immediate notification is less important.
How Do You Avoid False Downtime Alerts?
A single failed request does not always mean a real outage. Network interruptions, transient DNS failures and short-lived service problems can produce isolated failures. Reliable monitoring can reduce false alarms by repeating checks, using sensible timeouts and evaluating consecutive failures before declaring an incident.
Why Use External Uptime Monitoring?
Monitoring from the same server or network that hosts a website can miss problems affecting users elsewhere. External monitoring checks the service from outside the infrastructure and can therefore detect failures in the server, hosting network, DNS, TLS or other components that are invisible from inside the system.
Uptime Monitoring vs. Website Monitoring
Uptime monitoring focuses mainly on whether a service is reachable and responding. Website monitoring is broader and can also check SSL, DNS, security headers, domain information, content and other externally observable characteristics.
How Viglar Monitors Uptime
Viglar checks your website from outside your infrastructure and monitors whether it remains reachable and responsive. Uptime is one part of the wider Viglar monitoring model, alongside SSL, DNS, security headers, domain, content, reputation and other checks.
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