System Health Screen Reference

Every gauge, card and status on System → System Health, the rule that sets it, and the read behind it.

Every Element On The Screen

Labels are the words on the screen. The response field each one is drawn from is in the technical part below.

What This Screen Does Not Do

• The read sends no notification. The heavy-load banner and the Degraded chip are drawn by the screen from the latest reading, so they exist only while someone has the screen open.
• The read keeps no history. Each reading replaces the last one in memory and is not written to the database.
• It cannot restart a service. Updates are applied, and the automatic schedule is set, on System → Updates; restores are run from System → Backups & Recovery (see Backup, Restore & Updates).

What each kind of outage looks like from the API and from this screen is on Failure Modes.

If something here is not working as you expect, start with When something goes wrong.

The menu item is shown to administrators and to anyone whose role includes view_system. The same permission is required by every read below, so a person who cannot see the screen cannot call its API either.

The Reads Behind The Screen

The screen makes four reads and no writes. All four are answered by the compliance service and are gated on view_system alone, not on a plan.

• Sizes are bytes; host percentages are 0 to 100 with one decimal place. A container’s cpuPct is a share of one core, so it can exceed 100 on a multi-core server. host.cpuPct is null when the sample could not be taken, and host.disk is null when the disk could not be measured.
• Containers are sorted by cpuPct, highest first. Only the containers of your own instance are listed.
• runningCount counts every running container, including one that is failing its health check and is therefore also in unhealthyCount. The screen counts from the rows instead, so its three numbers never overlap.
• When the container list cannot be read the reply is still 200, with dockerAvailable: false, an empty containers array and the host figures filled in.
• Caching. A reading is reused for 25 seconds, and callers that arrive while one is being taken share it. Polling faster than that returns the same reading.

Response Field Behind Each Element

This table gives the response field each element on the screen is drawn from. What each element means is in the plain part above, under Every Element On The Screen; fields under host and containers are in the reply shown above.