deltatocumulative: Number of buckets in exponential histograms should be capped

[euroelessar]

Component(s)

processor/deltatocumulative

What happened?

Description

Currently size of an individual histogram is unbounded and can grow until OOM is reached.
This is prominent if an application has large distribution of data overall but only relatively small in an individual delta datapoint. In this case cumulative aggregation keeps the scale but keeps growing number of buckets to fit all the data.

Steps to Reproduce

Send two histogram datapoints with the same scale but drastically different offsets.

Expected Result

Cumulative exponential histogram is downscaled to keep around ≈160 buckets.

Actual Result

Exponential histogram grows number of buckets instead, leading to OOM.

Collector version

v0.101.0

Environment information

Environment

OS: Linux
Compiler(if manually compiled): go 1.22.2

OpenTelemetry Collector configuration

No response

Log output

No response

Additional context

No response

[github-actions]

Pinging code owners:

• processor/deltatocumulative: @sh0rez @RichieSams @jpkrohling

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

[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/deltatocumulative: @sh0rez @RichieSams @jpkrohling

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