Top N Resource Intensive Search Queries

[PritLadani]

Is your feature request related to a problem? Please describe.
Get the top N currently running queries based on the resource consumption by parent and children tasks.

Describe the solution you'd like
Based on the resource consumption of parent task and the children tasks, we can score the ongoing queries and expose an API to list down the top N most resource consuming queries and user can cancel a query based on the resource consumption. This can be achieved by getting the tasks using the Tasks API on-demand.

Describe alternatives you've considered

Additional context
Current version of List Tasks API gives us the resource consumption by currently running SearchShardTasks as well as SearchTasks. By leveraging the same, we can list down top N ongoing search queries based on their resource consumption.

[anasalkouz]

@PritLadani Can you list all related issues to the Meta issue ?

[PritLadani]

@anasalkouz Here are all the open issues related to Search Backpressure: https://github.com/opensearch-project/OpenSearch/issues?q=is%3Aopen+is%3Aissue+backpressure