[META] Add Fetch Phase to Search Profile #18864
Description
Please describe the end goal of this project
OpenSearch currently supports detailed profiling for the query and aggregation phases of search, enabling developers to analyze performance by timing the underlying operations. However, a significant gap exists in this feature, as it provides no insight into the fetch phase. This absence makes it difficult for developers to identify and resolve performance bottlenecks occurring during document retrieval.
To provide a complete performance picture, a fetch phase profile must be introduced. Consistent with the existing profilers, it should maintain timing information for the entire phase, alongside a granular breakdown of its key operations. The fetch phase profile should also support profiling of fetch phases outside of the standard fetch phase (i.e. inner hits fetch, top hits aggregation fetch).
Supporting References
[RFC] Adding Fetch Phase Profiling #18696
Add Fetch Phase to Search Profile #18664
Issues
- Add fetch phase to search profile #1764
- Expand fetch phase profiling to support queries that utilize multiple shards #18863
- Expand fetch phase profiling to support inner hits and top hits aggregation phases #18862
Related component
No response