In the current implementation of PD-Disagggregation, the decode server should know the request's prefill DP rank in bootstrapping. However, if we can only decide the dp rank in the dp_controller module, then in the current design, the decode server cannot get the prefill request's dp rank.

There are three methods to fix the issue:

• Change route API for bootstrap server, use bootstrap_room as the identifier instead of

url = f"http://{self.bootstrap_addr}/route?engine_rank={engine_rank}&target_dp_group={target_dp_group}"

To achieve this, we have to solve the PUT and GET orders for prefill to register the info and decode to fetch the info.

• After dp_controller has determined the dp rank, notify the decode server.
• Remove dp_controller's load balance functionality completely, every dp rank is decided by the external router.