Ranges, resolution and rates
Every chart in icLens reads the page’s time range. Choosing it well, and knowing how often data was recorded, explains most charts that look empty or jagged.
Choose a range
Section titled “Choose a range”Open the time range at the top of the page:
- Quick ranges: from the last 5 minutes to the last 5 years.
- Custom range…: exact From and To times, in your time zone or UTC.
- The arrows beside the range move it earlier or later by its own length.
A link keeps the range, so whoever opens it sees the same period.
How often data is recorded
Section titled “How often data is recorded”Monitor reads each canister every 5 minutes by default, and you can change it. A chart can never show more detail than that: a 1-minute view of 5-minute readings still has one reading every 5 minutes.
Data your code sends arrives as often as your code sends it.
Points on a chart
Section titled “Points on a chart”icLens draws up to about 600 points per chart, grouping readings for long ranges. Grouping keeps each period’s real last, lowest and highest value, so a spike never disappears. Gaps stay gaps.
Rates need several readings
Section titled “Rates need several readings”A rate, such as calls per second, compares readings over a window. With
readings every 5 minutes, a window shorter than that has nothing to compare.
Use [30m] or longer in PromQL, and expect a newly monitored canister to show
values before it shows rates.
Charts built into icLens pick a safe window for you.
Good to know
Section titled “Good to know”- History starts when collection starts. A longer range doesn’t add older data.
- A counter that resets, for example after an upgrade, is handled per canister before the fleet is added up.
- A data connection keeps data for as long as its Kept setting allows.