b0376abd4c
**[RFC]: Elastic Scaling Support for P/D Instances Based on KV Pool:**
https://github.com/vllm-project/vllm-ascend/issues/3380
### What this PR does / why we need it?
Support elastic scaling for P/D instances based on mooncake conncetor
deplayment.
**Support API routes**
* `/instances/add`: add prefill nodes or decode nodes to the list.
* `/instances/remove`: remove prefill nodes or decode nodes from the
list.
**Support functions**
* Support **adding** prefill nodes or decode nodes.
- If prefill or decode server deployed **after the proxy deployed**,
server can use `/instances/add` API to join the proxy server. The
prefill server or decode server sends a signal to the proxy server, and
the proxy server will check the status of the node util the node is
available.
* Support **removing** prefill nodes or decode nodes:
- Support using `/instances/remove` API to **delete the node** from the
proxy server.
### Does this PR introduce _any_ user-facing change?
For
`examples/disaggregated_prefill_v1/load_balance_proxy_server_example.py`:
**Add 2 params**
When adding nodes to the proxy, the proxy will wait the nodes to be
started util retrying a certain of times.
| name | type | default | help |
| ----- | ---- | ---- | ---- |
| max-waiting-retries | int | 3 | Maximum number of retries for waiting
nodes to be started |
| waiting-retry-interval | float | 10 | Check interval (seconds) for
waiting nodes to be started |
For example:
```shell
python load_balance_proxy_server_example.py \
--host 0.0.0.0 --port 9000 \
--prefiller-hosts 127.0.0.1 127.0.0.1 \
--prefiller-ports 8100 8101 \
--decoder-hosts 127.0.0.1 127.0.0.1 \
--decoder-ports 8200 8201 \
--max-waiting-retries 3 \
--waiting-retry-interval 10
```
**Add 2 API routings**
* Add instances: `instances/add`
For example, add 2 prefiller instances:
```shell
curl -X POST http://localhost:9000/instances/add \
-H "Content-Type: application/json" \
-d '{
"type": "prefill",
"instances": ["127.0.0.1:8102", "127.0.0.1:8103"]
}'
```
Response:
```shell
{"message": "add prefill instances: ['127.0.0.1:8102', '127.0.0.1:8103'].", "current_prefill_instances": ['127.0.0.1:8100', '127.0.0.1:8101', '127.0.0.1:8102', '127.0.0.1:8103'], "current_decode_instances": ['127.0.0.1:8200', '127.0.0.1:8201']}
```
If the node '127.0.0.1:8103' has not benn started:
```shell
{"message": "add prefill instances: ['127.0.0.1:8102']. Instances ['127.0.0.1:8103'] are waiting to be added.", "current_prefill_instances": ['127.0.0.1:8100', '127.0.0.1:8101', '127.0.0.1:8102'], "current_decode_instances": ['127.0.0.1:8200', '127.0.0.1:8201']}
```
* Remove instances: `instances/remove`
For example, remove 1 decoder instance:
```shell
curl -X POST http://localhost:9000/instances/remove \
-H "Content-Type: application/json" \
-d '{
"type": "decode",
"instances": "127.0.0.1:8201"
}'
```
Response:
```shell
{"message": "remove decode instances: ['127.0.0.1:8201'].", "current_prefill_instances": ['127.0.0.1:8100', '127.0.0.1:8101'], "current_decode_instances": ['127.0.0.1:8200']}
```
### How was this patch tested?
Run proxy and using `/instances/add` API to add nodes and
`/instances/remove` API to remove nodes
* vLLM version: v0.11.0.rc3
* vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0.rc3
- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c
Signed-off-by: yuxinshan <syx_ctyg@126.com>
Signed-off-by: CalvinXKY <kyxiezju@163.com>
vLLM Ascend Plugin
| About Ascend | Documentation | #sig-ascend | Users Forum | Weekly Meeting |
English | 中文
Latest News 🔥
- [2025/09] We released the new official version v0.9.1! Please follow the official guide to start deploy large scale Expert Parallelism (EP) on Ascend.
- [2025/08] We hosted the vLLM Beijing Meetup with vLLM and Tencent! Please find the meetup slides here.
- [2025/06] User stories page is now live! It kicks off with LLaMA-Factory/verl//TRL/GPUStack to demonstrate how vLLM Ascend assists Ascend users in enhancing their experience across fine-tuning, evaluation, reinforcement learning (RL), and deployment scenarios.
- [2025/06] Contributors page is now live! All contributions deserve to be recorded, thanks for all contributors.
- [2025/05] We've released first official version v0.7.3! We collaborated with the vLLM community to publish a blog post sharing our practice: Introducing vLLM Hardware Plugin, Best Practice from Ascend NPU.
- [2025/03] We hosted the vLLM Beijing Meetup with vLLM team! Please find the meetup slides here.
- [2025/02] vLLM community officially created vllm-project/vllm-ascend repo for running vLLM seamlessly on the Ascend NPU.
- [2024/12] We are working with the vLLM community to support [RFC]: Hardware pluggable.
Overview
vLLM Ascend (vllm-ascend) is a community maintained hardware plugin for running vLLM seamlessly on the Ascend NPU.
It is the recommended approach for supporting the Ascend backend within the vLLM community. It adheres to the principles outlined in the [RFC]: Hardware pluggable, providing a hardware-pluggable interface that decouples the integration of the Ascend NPU with vLLM.
By using vLLM Ascend plugin, popular open-source models, including Transformer-like, Mixture-of-Expert, Embedding, Multi-modal LLMs can run seamlessly on the Ascend NPU.
Prerequisites
- Hardware: Atlas 800I A2 Inference series, Atlas A2 Training series, Atlas 800I A3 Inference series, Atlas A3 Training series, Atlas 300I Duo (Experimental)
- OS: Linux
- Software:
- Python >= 3.10, < 3.12
- CANN == 8.3.rc2 (Ascend HDK version refers to here)
- PyTorch == 2.8.0, torch-npu == 2.8.0
- vLLM (the same version as vllm-ascend)
Getting Started
Please use the following recommended versions to get started quickly:
| Version | Release type | Doc |
|---|---|---|
| v0.12.0rc1 | Latest release candidate | QuickStart and Installation for more details |
| v0.11.0 | Latest stable version | QuickStart and Installation for more details |
Contributing
See CONTRIBUTING for more details, which is a step-by-step guide to help you set up development environment, build and test.
We welcome and value any contributions and collaborations:
- Please let us know if you encounter a bug by filing an issue
- Please use User forum for usage questions and help.
Branch
vllm-ascend has main branch and dev branch.
- main: main branch，corresponds to the vLLM main branch, and is continuously monitored for quality through Ascend CI.
- vX.Y.Z-dev: development branch, created with part of new releases of vLLM. For example,
v0.7.3-devis the dev branch for vLLMv0.7.3version.
Below is maintained branches:
| Branch | Status | Note |
|---|---|---|
| main | Maintained | CI commitment for vLLM main branch and vLLM v0.12.0 tag |
| v0.7.1-dev | Unmaintained | Only doc fixed is allowed |
| v0.7.3-dev | Maintained | CI commitment for vLLM 0.7.3 version, only bug fix is allowed and no new release tag any more. |
| v0.9.1-dev | Maintained | CI commitment for vLLM 0.9.1 version |
| v0.11.0-dev | Maintained | CI commitment for vLLM 0.11.0 version |
| rfc/feature-name | Maintained | Feature branches for collaboration |
Please refer to Versioning policy for more details.
Weekly Meeting
- vLLM Ascend Weekly Meeting: https://tinyurl.com/vllm-ascend-meeting
- Wednesday, 15:00 - 16:00 (UTC+8, Convert to your timezone)
License
Apache License 2.0, as found in the LICENSE file.