[Feature Request] Segment Profiling

[ajleong623]

Is your feature request related to a problem? Please describe

For concurrent segment searches, the profiling information is limited to the times for each phase in the query and the statistics across the slices. However, there are not information on the internals of the slices.

Describe the solution you'd like

Should there be information on the segments in each of the slices the query ran? With the incoming feature of intrasegment concurrent search worked on by @prudhvigodithi , should there also be information on the partitions of the segments search on?

Related component

Search

Describe alternatives you've considered

No response

Additional context

No response

[sandeshkr419]

[Search Triage] @jainankitk tagging you for taking a look!

[asimmahmood1]

Thanks for putting up this issue. This as been discussed this a few times in the past.

@jainankitk will be back next week, in the mean time you can catch up on the Lucene level change he made: https://www.youtube.com/watch?v=6Du_7HBT-bs

High level idea being it'll be good to know when a slice started and ended, so you can check things like: longest poll, number of segments per slice, etc.

I did look into this myself sometime back, turns out it'll require some changes in profiling classes.

There are some query profile visualizers that would need to be updated to make it easy to view: e.g. #19035

[prudhvigodithi]

I'm open for thought and discuss what can be part of profiling or debugger. IMO the main things would be:

• Information about segments and partitions.
• How many slices, inside each slice we need how many segments or partitions are part of it.
• Also if enabled intra segment. How a segment is partitioned today, how many partitions and range of each partition.