Server monitoring needs something running on the server, usually an agent. Hyperping's agent installs with one command on Linux, macOS, and Windows, sends CPU, memory, filesystem, disk I/O, and network metrics every 30 seconds, and holds around 50 MB of memory. When a server stops reporting, it's marked Stale after 30 seconds and Offline after 90 seconds by default, which opens an outage and pages the server's escalation policy like a failed uptime check.
They answer different questions, and neither replaces the other. An external uptime check tells you within seconds that customers are affected, from outside your network, with no agent to trust. Server metrics tell you why, and often show the problem building for hours first: available memory sliding down, free space shrinking at a steady rate, load average creeping past the number of cores.
Run both. Page on the external check, because it means users are affected now. Use the server timeline to diagnose, and to catch the slow failures an outside check can't see until they become an outage.
An agent that stops reporting is an incident, not a quiet server. A host that crashed, lost its network, or ran out of memory badly enough to kill the agent sends nothing, and a dashboard that only alerts on thresholds stays silent. Alert on missing data first, then on resource limits.
No. It only makes outbound HTTPS requests, and queues metrics on disk when it can't send them, so graphs stay complete through network blips and reboots.
For host metrics, yes: install the agent on the VM or node, and you see the load of every container it runs. Per-container and per-process metrics need a different tool.
The Free plan includes 1 server. Paid plans include 5, 20, or 100, with server alerting, and extra servers cost $2 a month, or $1.50 on Business. Compare with other tools in the server monitoring cost calculator.