Benchmark the impl to get the suggested volumn upper threshold for Flink streaming RLI

### Task Description

**What needs to be done:**

- [ ] benchmark the perf of the RLI to get the numbers
- [ ] have basic conclusion of the upper threshold of the volumn (records per second)

**Why this task is needed:**
As a practice tuition.

### Task Type

Code improvement/refactoring

### Related Issues

**Parent feature issue:** (if applicable )
#17647

Start by reading the parent feature issue #17647 and locating the RLI implementation and benchmark entry point in the repository. Run a reproducible Flink streaming benchmark, measure records per second, and document the observed upper threshold and assumptions. No files or tests are named, so the exact entry point and completion criteria need clarification first.

Written by the indexing model from the issue text.