Metrics history & resolution

Metrics are kept at two levels of detail, and there is nothing to configure or pay attention to — charts pick the right one from the time range you select:

Detail	Kept for
Per-minute (as collected)	35 days
Hourly summary	400 days

The hourly summary is built continuously from the per-minute data: gauge-style metrics (CPU, memory, temperatures) keep their hourly average, counter-style metrics (network and disk totals) their hourly progression.

How charts choose

The chart range picker runs from 3H to 90D. Ranges that start within roughly the last month (32 days) draw per-minute data; ranges reaching further back draw from the hourly history, with chart points at least two hours apart. Either way a chart’s right edge is current — a 90-day chart still ends at now, not at the last completed hour.

Two things follow from the resolution switch:

• A short spike — a two-minute CPU burst, say — is visible while the range stays within the per-minute month, but flattens into its hourly average in older data. If a brief event from months ago matters, the alert incident it fired is a better record than the chart.
• The per-chart stats (Cur/Avg/p95/Max) are computed from the points the chart is showing, so they follow the same resolution as the chart itself.

When data is deleted

• Age: per-minute data past 35 days and hourly data past 400 days expire on their own — that is the whole story, there are no per-plan knobs today.
• Removing a server deletes its metric history immediately along with the server row, and there is no undo — the confirmation and its consequences are covered in Update or uninstall the collector.
• A server that is merely offline keeps its history: data already reported stays until it ages out on the schedule above, so a decommissioned-but-not-removed server’s charts remain readable for weeks.

There is no self-service account deletion yet — removing your servers removes your metric data, but the account itself currently stays.