Deploy a Qdrant collection across a cluster with sharding and replication, tune read/write consistency, and manage shards via the cluster API

Documented steps

1. Set sharding and replication at creation: PUT /collections/{collection_name} with {"vectors":{"size":300,"distance":"Cosine"},"shard_number":6,"replication_factor":2,"write_consistency_factor":2}.
2. shard_number defaults to the node count and cannot be changed without recreating the collection on self-hosted Qdrant. Plan ahead — e.g. 12 shards lets you scale 1 -> 2 -> 3 -> 6 -> 12 nodes.
3. write_consistency_factor (default 1, max = replication_factor) sets how many replicas must acknowledge a write before the client gets a response.
4. Move a shard: POST /collections/{collection_name}/cluster with {"move_shard":{"shard_id":0,"from_peer_id":381894127,"to_peer_id":467122995,"method":"snapshot"}}.
5. Add a replica: {"replicate_shard":{"shard_id":0,"from_peer_id":381894127,"to_peer_id":467122995}}. Remove one: {"drop_replica":{"shard_id":0,"peer_id":381894127}}.
6. Choose the transfer method: stream_records (default, weak ordering, reindexes HNSW and quantization on the target), snapshot (v1.7.0+, strong ordering, transfers index and quantization as-is), wal_delta (v1.8.0+, target shard must already exist, transfers only the WAL diff).
7. Set read consistency per query: POST /collections/{collection_name}/points/query?consistency=majority. Values: an integer node count, 'majority', 'quorum', or 'all'. Default is 1.
8. Set write ordering per write: PUT /collections/{collection_name}/points?ordering=strong. Values: weak (default), medium, strong.
9. On permanent node loss (needs 3+ nodes since Raft requires >50% healthy): DELETE /cluster/peer/{peer_id}, bootstrap a replacement, then re-run replicate_shard. Qdrant Cloud automates this.
10. Reference: https://qdrant.tech/documentation/scaling/distributed_deployment/
11. Reference: https://qdrant.tech/documentation/scaling/consistency-guarantees/
12. Reference: https://qdrant.tech/documentation/scaling/node-failure-recovery/