Metrics are recorded and retained for each instance according to a 'roll-up' policy. As time progresses, the metric data is rolled up from a fine granularity to a coarser one by the end 3 months.
The roll-up policy is as follows:
- 10 SECOND resolution for the first 6 hours, then
- 1 MINUTE resolution for 2 days, then
- 10 MINUTE resolution for 2 weeks, then
- 1 HOUR resolution for 3 months, then
- 1 DAY resolution for one year.
When a host or instance is no longer monitored (as when the agent is uninstalled) historical data is not removed and will remain as described above. You will always be able to see your host's metrics in the views for the time period that the agent was installed and reporting.