[processor/cumulativetodelta] Support persistant storage.

[h0cheung]

Component(s)

processor/cumulativetodelta

Is your feature request related to a problem? Please describe.

When the collector is restarted and the last point before the restart does not exist, the delta value cannot be calculated for the new first point, it can only be discarded. This causes a breakpoint, and the total for the period is calculated to be lower than the true value.

Describe the solution you'd like

Support persistent storage. This way the collector could get the last value to calculate the delta value after restarting.

Describe alternatives you've considered

No response

Additional context

No response

[github-actions]

Pinging code owners for processor/cumulativetodelta: @TylerHelmuth. See Adding Labels via Comments if you do not have permissions to add labels yourself. For example, comment '/label priority:p2 -needs-triaged' to set the priority and remove the needs-triaged label.

[github-actions]

This issue has been inactive for 60 days. It will be closed in 60 days if there is no activity. To ping code owners by adding a component label, see Adding Labels via Comments, or if you are unsure of which component this issue relates to, please ping @open-telemetry/collector-contrib-triagers. If this issue is still relevant, please ping the code owners or leave a comment explaining why it is still relevant. Otherwise, please close it.

Pinging code owners:

• processor/cumulativetodelta: @TylerHelmuth

See Adding Labels via Comments if you do not have permissions to add labels yourself.