[Bug]: Aggregation over time hides partial or empty data

[ralphm]

Bug description

When a timeseries has gaps with empty data, when zooming out to the point that the gap would be aggregated into a single rendered data point, the empty or partial indicators are no longer shown. This removes a critical signal while troubleshooting issues.

Expected behavior

Aggregation over time must keep showing empty / partial.

Steps to reproduce

1. Find a timeseries with a gap.
2. Zoom out far enough that the gap is covered by a "pixel".
3. See the indicators for partial / empty data go missing.

Screenshots

Last 10 days with gap

Last 14 days without gap

Error Logs

No response

Desktop

No response

Additional context

No response

[ralphm]

@ktsaou is this an aggregation issue at the Agent, in Cloud, or both?

[juacker]

@ralphm based on the issue description, I would say that the cloud is working as expected:

1. in cloud we don't perform time-aggregations, the agent handles the downsampling.
2. When aggregating point annotations between different series, we always keep any non null value, meaning that if a series that the cloud aggregates contains a non null value as partial data or overflow, we would set it.