The system needs adaptive scaling for Anomaly Detection (AD) indices to handle horizontal scalability issues. When scaling clusters (e.g., from 10 to 100 data nodes), the current AD result index shard settings remain static, leading to potential concurrency problems with bulk write requests.
**Is your feature request related to a problem? Please describe.** From Yaliang's comment: https://github.com/opensearch-project/anomaly-detection/pull/121#issuecomment-876741491 Have some concern about the horizontal scalability. For example, if user scale cluster from 10 data nodes to 100 data nodes, then will have 100 worker nodes running entities, that means we may send out 100 bulk write AD result requests concurrently. But the AD result index shard setting is still the same, that may bring higher write load and user's general bulk write request may impacted. Confirm with PM/SDM if the concern of horizontal scalable issue is reasonable. **Describe the solution you'd like** We will need adaptive scaling of AD indices to scale index shards when needed. **Describe alternatives you've considered** Throttling index usage at the cost of AD usability.