Set proper 'text/event-stream; charset=utf-8' media type for streaming
requests instead of hardcoded 'application/json'
### What this PR does / why we need it?
This PR fixes an issue in the disaggregated prefill proxy server where
streaming requests (`"stream": true`) were always returned with a
hardcoded `Content-Type: application/json`, even when the backend vLLM
servers correctly returned Server-Sent Events (SSE) with `Content-Type:
text/event-stream; charset=utf-8`.
Specifically, the proxy used `StreamingResponse` with a fixed
`media_type` of `application/json`, which caused FastAPI to override the
response headers and break proper SSE semantics. As a result, clients
(e.g. `curl -i`, EventSource, or OpenAI-compatible SDKs) could not
reliably receive token-by-token streaming output.
In addition, this incorrect response type causes compatibility issues
with benchmarking and load-testing tools such as **EvalScope**. When
streaming is enabled, these tools expect SSE-formatted responses to
correctly parse token usage information. With the incorrect
`application/json` content type, EvalScope fails to parse the response
and reports errors similar to:`2025-12-15 09:27:56 - evalscope - ERROR:
Failed to parse usage from response: list index out of range. Response:
[]`
This PR updates the proxy to:
- Detect whether the incoming request is a streaming request
(`stream=true`)
- Use `text/event-stream; charset=utf-8` for streaming responses
- Preserve `application/json` for non-streaming responses
This aligns the proxy behavior with native vLLM prefill/decoder servers
and the OpenAI-compatible streaming API contract.
Fixes incorrect streaming response headers that prevented proper
real-time token delivery.
### Does this PR introduce _any_ user-facing change?
None
### How was this patch tested?
This change was tested manually using a disaggregated prefill + decode
setup
with the proxy server.
### Test Steps
1. Start prefiller and decoder vLLM servers:
```bash
vllm serve --host 0.0.0.0 --port 8001 ...
vllm serve --host 0.0.0.0 --port 8002 ...
```
2. Start the proxy server:
```bash
python load_balance_proxy_server_example.py \
--host 127.0.0.1 --port 8000 \
--prefiller-hosts 127.0.0.1 --prefiller-ports 8001 \
--decoder-hosts 127.0.0.1 --decoder-ports 8002
```
3. Send a streaming completion request through the proxy:
```bash
curl -i -X POST http://127.0.0.1:8000/v1/completions \
-H "Content-Type: application/json" \
-d '{
"model": "test",
"prompt": "hello",
"max_tokens": 3,
"stream": true
}'
```
4. Verify the following:
- The response header is Content-Type: text/event-stream; charset=utf-8
- Tokens are streamed incrementally as SSE data: events
- Non-streaming requests still return application/json
No automated tests were added because this change affects an example
proxy
server and is limited to HTTP response headers. The behavior is directly
verifiable using standard SSE-compatible clients.
- vLLM version: v0.16.0
- vLLM main:
15d76f74e2
Signed-off-by: zrj026 <zhangrunjiang026@gmail.com>
Co-authored-by: zrj026 <zhangrunjiang026@gmail.com>
### What this PR does / why we need it?
The incorrect regular expression syntax `.*[UE4M3|ue4m3].*` actually
ignores all words containing any of the following characters: `u, e, 4,
m, 3, |`
```yaml
extend-ignore-identifiers-re = [".*Unc.*", ".*_thw",
".*UE8M0.*", ".*[UE4M3|ue4m3].*", ".*eles.*", ".*fo.*", ".*ba.*",
".*ot.*", ".*[Tt]h[rR].*"]
```
===fix===>
```yaml
extend-ignore-identifiers-re = [".*Unc.*", ".*_thw",
".*UE8M0.*", ".*(UE4M3|ue4m3]).*", ".*eles.*", ".*fo.*", ".*ba.*",
".*ot.*", ".*[Tt]h[rR].*"]
```
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.15.0
- vLLM main:
9562912cea
Signed-off-by: MrZ20 <2609716663@qq.com>
### What this PR does / why we need it?
The variables `self.prefiller_heap` `self.decoder_heap` are used as
`List[tuple[float, int, ServerState]]` but defined as `List[tuple[int,
int, ServerState]]`, which leads to the failed of mypy, see
https://github.com/vllm-project/vllm-ascend/actions/runs/21351411010/job/61448739554?pr=6265
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.14.1
- vLLM main:
d68209402d
Signed-off-by: wangli <wangli858794774@gmail.com>
### What this PR does / why we need it?
For the proxy, we should remove instances when the proxy are not
processing requests.
But sometimes, We need to **isolate** some faulty nodes when a large
number of **requests** are coming in.
So we support to **isolate** faulty nodes by **lowering their priority**
and **deleted** them when the proxy does not process requests.
### Does this PR introduce _any_ user-facing change?
For
`examples/disaggregated_prefill_v1/load_balance_proxy_server_example.py`,
when using `/instances/remove` API to delete the node from the proxy
server:
```txt
curl -X POST http://localhost:9000/instances/remove \
-H "Content-Type: application/json" \
-d '{
"type": "decode",
"instances": "127.0.0.1:8201"
}'
```
There are 2 situations:
* 【New】When the proxy is processing requests, isolate the nodes and
remove them when the proxy is free.
```txt
{"message": "Instances ['127.0.0.1:8201'] are isolated and waiting to be removed.", "current_prefill_instances": ['127.0.0.1:8100', '127.0.0.1:8101'], "current_decode_instances": ['127.0.0.1:8200', '127.0.0.1:8201']}
```
* When the proxy is free, remove the nodes directly.
```txt
{"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?
- vLLM version: v0.13.0
- vLLM main:
11b6af5280
Signed-off-by: yuxinshan <syx_ctyg@126.com>
**[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>
### What this PR does / why we need it?
fix fastapi version == 0.123.10(<0.124.0)
- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c
Signed-off-by: hfadzxy <starmoon_zhang@163.com>
### What this PR does / why we need it?
This PR adds a load-balance dp proxy server which can be used in
external DP scenario without Disaggregated-Prefill enabled. What's more,
add a doc of external dp and load-balance dp proxy server.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
See the new doc.
- vLLM version: v0.11.0
- vLLM main:
2918c1b49c
---------
Signed-off-by: whx-sjtu <2952154980@qq.com>
### What this PR does / why we need it?
fix proxy when host ip using domain name
- vLLM version: v0.11.0
- vLLM main:
2918c1b49c
---------
Signed-off-by: liziyu <liziyu16@huawei.com>
### What this PR does / why we need it?
pd proxy support ipv6, mooncake connector check whether the IPv6 address
is used and notify the user.
- vLLM version: v0.11.0
- vLLM main:
2918c1b49c
---------
Signed-off-by: liziyu <liziyu16@huawei.com>
### What this PR does / why we need it?
fix proxy decode bug when parsing non-UTF-8 characters.
- vLLM version: v0.11.0
- vLLM main:
c9461e05a4
---------
Signed-off-by: CHEN <116010019@link.cuhk.edu.cn>
### What this PR does / why we need it?
Modify the recalculation logic to prevent waiting requests from filling
up the D node KVCache
- vLLM version: v0.11.0rc3
- vLLM main:
17c540a993
Signed-off-by: underfituu <hzhucong@163.com>
### What this PR does / why we need it?
This PR is aimed to fix the recomputing out of memory bug in decode
instance. When recomputing happens in decode, kv cache usage may exceed
the pre-allocated memory, and it will cause OOM.
So we propose a new scheduling strategy, when decode instance cannot
allocate new block for running requests, we will stop the request that
will be preempted. These stopped request will be recognied by proxy, and
they will be send to prefill instance again to calculate kvc and then
direct to decode instance.
This is a temporary plan to fix the bug. The long-term stratege is to
use CPU offload in decode instance.
### Does this PR introduce _any_ user-facing change?
An extra ascend configuration option **-- recompute_scheduler_enable =
True** is added to enable this strategy. The default value is False
### How was this patch tested?
- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0
---------
Signed-off-by: CHEN <116010019@link.cuhk.edu.cn>
### What this PR does / why we need it?
Resolve the issue of waiting queue accumulation when requests are
canceled.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
By ci
- vLLM version: v0.10.1.1
- vLLM main:
006477e60b
---------
Signed-off-by: wangxiaoteng666 <wangxiaoteng@huawei.com>
### What this PR does / why we need it?
The PR is the cherry-pick from v0.9.1
https://github.com/vllm-project/vllm-ascend/pull/1953
This PR introduce a new load balance proxy server example implementation
for disaggregated pd, which support simple token&kv_cache aware load
balance routing strategy for the disaggregated pd system compared with
origin round robin toy_proxy.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
tested on real workload and unittest
- vLLM version: v0.10.0
- vLLM main:
ad57f23f6a
---------
Signed-off-by: ganyi <pleaplusone.gy@gmail.com>
