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[router] Speak cleartext h2c on both edges: serve it inbound, forward it outbound (#39006)

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Co-authored-by: Kangyan Zhou <kangyan.zhou@radixark.ai>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
This commit is contained in:
Kangyan-Zhou
2026-09-15 22:30:31 -07:00
committed by GitHub
co-authored by Kangyan Zhou Claude Opus 5
parent c1f5b4736a
commit afde31a2f5
17 changed files with 1009 additions and 41 deletions
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experimental/sgl-router/Cargo.lock
Generated
+3
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@@ -2887,6 +2887,7 @@ dependencies = [
"bytes",
"futures-core",
"futures-util",
"h2",
"http",
"http-body",
"http-body-util",
@@ -3294,6 +3295,8 @@ dependencies = [
"futures",
"hf-hub",
"http-body-util",
"hyper",
"hyper-util",
"k8s-openapi",
"kube",
"minijinja",
experimental/sgl-router/Cargo.toml
+21 -2
View File
@@ -38,10 +38,21 @@ chrono = { version = "0.4", default-features = false, features = ["clock"] }
# Async runtime + http
tokio = { version = "1.42", features = ["full"] }
axum = { version = "0.8", features = ["macros", "tracing"] }
# http2 on both sides: axum serves cleartext h2c on the inbound listener, reqwest
# dials it outbound.
#
# axum's `http2` looks redundant and is not — please don't drop it. `axum::serve`
# runs on hyper-util's auto Builder, whose HTTP/2 branch is compiled by
# `hyper-util/http2`, and that arrives today only transitively, via
# sgl-kv-indexer -> tonic "transport" -> tonic/server -> hyper-util/server-auto
# (which is server + http1 + http2). So the listener speaks h2c whether or not
# this line exists. Declaring it forwards `hyper-util/http2` from axum directly,
# so inbound h2c no longer rides on a gRPC dependency it has nothing to do with,
# and it enables HTTP/2 extended CONNECT for h2 websockets.
axum = { version = "0.8", features = ["macros", "tracing", "http2"] }
tower = { version = "0.5", features = ["full"] }
tower-http = { version = "0.6", features = ["trace", "compression-gzip", "cors", "timeout", "request-id"] }
reqwest = { version = "0.12", features = ["stream", "json", "rustls-tls"], default-features = false }
reqwest = { version = "0.12", features = ["stream", "json", "rustls-tls", "http2"], default-features = false }
sgl-kv-indexer = { path = "sgl-kv-indexer" }
# Serialization
@@ -81,6 +92,14 @@ zeromq = { version = "0.6", default-features = false, features = ["tokio-runtime
[dev-dependencies]
dirs = "5"
http-body-util = "0.1"
# HTTP/2-only mock server for the proxy h2c forwarding tests (tests/proxy/h2c_forward.rs).
# `http1` as well as `http2`: tests/proxy/pd_protocol_binding.rs drives both
# `hyper::server::conn::http1` and `::http2` to build single-protocol mocks.
# `http1` arrives transitively via axum's defaults today; declaring it here
# means an axum `default-features = false` later fails at the dependency
# rather than as an unresolved import in a test.
hyper = { version = "1", features = ["server", "http1", "http2"] }
hyper-util = { version = "0.1", features = ["tokio"] }
serde = { version = "1", features = ["derive"] }
serde_json = "1"
tempfile = "3"
experimental/sgl-router/README.md
+44 -1
View File
@@ -6,7 +6,8 @@ Serves a single model and routes across its workers. Exposes
`/v1/tokenize`, `/v1/detokenize`, `/v1/models`, `/v1/chat/completions`
(buffered and SSE), plus `/healthz` / `/readyz` and `/metrics`. Worker
pools come from either a static URL list or Kubernetes EndpointSlice
discovery.
discovery. Both edges speak cleartext HTTP/2 where the peer does — see
[HTTP/2](#http2).
## Building
@@ -68,6 +69,48 @@ The Indexer replaces the Router-local radix tree as the native Cache-Aware
signal. Query timeouts and local concurrency are bounded by the two Indexer
options, which default to 100 ms and 32 respectively.
## HTTP/2
There is nothing to configure. The router negotiates per connection inbound and
resolves the protocol per worker outbound; every combination below is reached
automatically, and HTTP/1.1 remains a supported peer on both edges.
**Inbound.** The listener accepts cleartext HTTP/2 (h2c, prior knowledge) and
HTTP/1.1 on the same `--port`, chosen per connection. A mesh sidecar or
load balancer that prefers h2c multiplexes over one connection instead of
opening one per request; an HTTP/1.1 client is unaffected.
**Outbound.** At registration the router reads each worker's `/server_info` and
forwards over cleartext h2c only when that worker reports `--enable-http2` (the
engine's Granian server, which serves h2c and HTTP/1.1 together) **and** the
worker URL is cleartext. Everything else uses the default client, which speaks
HTTP/1.1 in cleartext and negotiates ALPN `h2, http/1.1` over TLS:
| `/server_info` | worker URL | router forwards over |
|---|---|---|
| `enable_http2: true` | `http://` | cleartext h2c |
| `enable_http2: true` | `https://` | HTTP/2 over TLS, by ALPN |
| `enable_http2: false`, or absent | any | HTTP/1.1 (cleartext) or ALPN (TLS) |
The choice is per worker, not fleet-wide, so a mixed fleet works and one
worker's state never changes another's. The flag comes from the `/server_info`
launch record, which has reported it all along, so no engine change is needed.
A worker whose `/server_info` does not answer has no readable protocol and
forwards over HTTP/1.1 for as long as it stays registered — a throughput cost,
never a correctness one. Admin fan-out (`/flush_cache`) always uses the default
client, because it addresses every worker at once rather than a selected one.
Two things worth knowing when debugging. h2c is prior-knowledge only — there is
no negotiation and no fallback — which is why the router requires the engine's
own `enable_http2` report before using it. And a worker's protocol is fixed
for as long as that worker stays registered: it is read once, at registration,
and never re-read. Under the K8s backend a restarting engine flips its
EndpointSlice to `ready=false`, which is a `Removed` → `Added` cycle and so a
fresh reading; under `--worker-urls` the fan-out happens once at startup and
nothing re-registers. So a worker registered over h2c that later stops serving
it (a proxy interposed on its port, say) is not detected until it
is re-registered; its circuit breaker will open in the meantime.
## Upgrading from `cache_aware_zmq`
The `cache_aware_zmq` policy has been removed. Configurations using it should
experimental/sgl-router/src/main.rs
+4
View File
@@ -167,6 +167,10 @@ async fn main() -> Result<()> {
sgl_router::policies::active_load::spawn_janitor(Arc::clone(&active_load), sweep_interval);
// Spawn discovery + manager tasks.
// The manager resolves each worker's wire protocol from its `/server_info`
// and stamps it onto the registered worker. The proxy holds one client per
// protocol and selects by the worker's protocol per request, so the manager
// needs no proxy handle.
let (event_rx, discovery_handle) = sgl_router::discovery::spawn_discovery(&cfg)
.await
.context("spawn discovery")?;
experimental/sgl-router/src/proxy/mod.rs
+73 -10
View File
@@ -8,6 +8,7 @@ pub mod sse;
use crate::health::circuit_breaker::CircuitBreaker;
use crate::server::error::ApiError;
use crate::server::header_utils::should_forward_request_header;
use crate::workers::WireProtocol;
use anyhow::Context;
use axum::body::Body;
use axum::http::{HeaderMap, HeaderName, HeaderValue, Response};
@@ -32,28 +33,68 @@ fn parse_worker_url(worker_url: &str, breaker: &CircuitBreaker) -> Result<Url, A
#[derive(Debug)]
pub struct Proxy {
pub client: Client,
/// The negotiating client: HTTP/1.1 in cleartext, and ALPN `h2, http/1.1`
/// over TLS. Safe against any engine, which is why it is also the client
/// for side-channel admin traffic (`/flush_cache`).
default_client: Client,
/// Cleartext h2c (HTTP/2 prior knowledge). No negotiation happens, so this
/// is used only for workers whose `/server_info` reported `--enable-http2`
/// on a cleartext URL.
h2c_client: Client,
/// Wall-clock timeout applied to non-streaming upstream requests. Streaming
/// requests deliberately do not use this (long generations are valid).
pub request_timeout: Duration,
}
/// Build a forwarding client for `protocol`, sharing pool/connect tuning
/// across protocols. The h2c variant pins HTTP/2 prior knowledge, which is
/// what Granian's `HTTPModes.auto` serves on a plaintext port; plaintext has
/// no ALPN, so prior knowledge is the only way to reach it.
fn build_client(protocol: WireProtocol) -> Result<Client, anyhow::Error> {
let builder = Client::builder()
.pool_max_idle_per_host(64)
.connect_timeout(Duration::from_secs(5));
match protocol {
WireProtocol::Http1 => builder,
WireProtocol::H2c => builder.http2_prior_knowledge(),
}
.build()
.context("build reqwest client")
}
impl Proxy {
/// Build a proxy. `request_timeout` is the per-request wall-clock budget for
/// non-streaming forwards. Connect timeout is hard-coded to 5 s — even a
/// streaming request fails fast at TCP setup if the worker is unreachable.
///
/// WHY both clients up front: protocol is a per-worker property resolved
/// from each engine's `/server_info`, so the request path must be able to
/// pick either one per request. Building them here reduces that to a
/// selection — no per-request client construction, and no single shared
/// client whose first writer decides the protocol for the whole fleet.
pub fn new(request_timeout: Duration) -> Result<Self, anyhow::Error> {
let client = Client::builder()
.pool_max_idle_per_host(64)
.connect_timeout(Duration::from_secs(5))
.build()
.context("build reqwest client")?;
Ok(Self {
client,
default_client: build_client(WireProtocol::Http1)?,
h2c_client: build_client(WireProtocol::H2c)?,
request_timeout,
})
}
/// The forwarding client for `protocol`, taken from the selected worker's
/// [`crate::workers::Worker::protocol`].
fn client_for(&self, protocol: WireProtocol) -> &Client {
match protocol {
WireProtocol::Http1 => &self.default_client,
WireProtocol::H2c => &self.h2c_client,
}
}
/// The client for side-channel admin traffic (e.g. `/flush_cache`), which
/// fans out across workers and so cannot use any one worker's protocol.
pub fn admin_client(&self) -> &Client {
&self.default_client
}
/// Classify a reqwest error into the right `ApiError` variant, given an
/// explicit worker URL. Called from the breaker-gated `forward_*_to`
/// methods, which carry per-request worker URLs (not a single proxy-level
@@ -91,6 +132,7 @@ impl Proxy {
pub async fn forward_json_to(
&self,
worker_url: &str,
protocol: WireProtocol,
breaker: &CircuitBreaker,
path: &str,
headers: &HeaderMap,
@@ -105,7 +147,7 @@ impl Proxy {
let url = worker_url.join(path).map_err(|e| {
ApiError::Internal(anyhow::Error::new(e).context(format!("join worker path {path}")))
})?;
let mut req = self.client.post(url.clone()).body(body);
let mut req = self.client_for(protocol).post(url.clone()).body(body);
for (k, v) in headers {
if should_forward_request_header(k) {
req = req.header(k, v);
@@ -164,13 +206,14 @@ impl Proxy {
/// for the full streaming lifetime — without which a long-running SSE
/// response would under-report load.
// Each parameter is a distinct, required input to a single upstream
// forward (target, breaker, path, headers, body, plus the
// forward (target, protocol, breaker, path, headers, body, plus the
// streaming-lifetime callbacks). Bundling them into a struct purely to
// satisfy the arg-count heuristic would add indirection without clarity.
#[allow(clippy::too_many_arguments)]
pub async fn forward_streaming_to(
&self,
worker_url: &str,
protocol: WireProtocol,
breaker: &Arc<CircuitBreaker>,
path: &str,
headers: &HeaderMap,
@@ -188,7 +231,7 @@ impl Proxy {
let url = worker_url.join(path).map_err(|e| {
ApiError::Internal(anyhow::Error::new(e).context(format!("join worker path {path}")))
})?;
let mut req = self.client.post(url.clone()).body(body);
let mut req = self.client_for(protocol).post(url.clone()).body(body);
for (k, v) in headers {
if should_forward_request_header(k) {
req = req.header(k, v);
@@ -274,4 +317,24 @@ mod tests {
let p = Proxy::new(Duration::from_secs(5)).unwrap();
assert_eq!(p.request_timeout, Duration::from_secs(5));
}
/// `client_for` routes each protocol to its own field, and admin traffic
/// shares the default client. Asserting the two clients differ by address
/// would be vacuous — they are distinct struct fields, so that holds even
/// if `build_client` ignored its argument. What the selector must get right
/// is the mapping, so pin that instead; the on-the-wire difference between
/// the two clients is covered by tests/proxy/h2c_forward.rs.
#[tokio::test]
async fn client_for_maps_each_protocol_to_its_own_client() {
let p = Proxy::new(Duration::from_secs(5)).unwrap();
assert!(std::ptr::eq(
p.client_for(WireProtocol::Http1),
&p.default_client
));
assert!(std::ptr::eq(p.client_for(WireProtocol::H2c), &p.h2c_client));
assert!(std::ptr::eq(
p.client_for(WireProtocol::Http1),
p.admin_client()
));
}
}
experimental/sgl-router/src/server/routes/cache.rs
+6 -2
View File
@@ -100,8 +100,12 @@ pub async fn flush_cache(State(ctx): State<Arc<AppContext>>) -> Response {
.into_response();
}
let (successful, failed) =
fan_out_flush(&workers, &ctx.proxy.client, ctx.proxy.request_timeout).await;
let (successful, failed) = fan_out_flush(
&workers,
ctx.proxy.admin_client(),
ctx.proxy.request_timeout,
)
.await;
// Partial failure is an operational event an operator needs to see at the
// common production log level — match the rest of the router, which warns
experimental/sgl-router/src/server/routes/chat.rs
+6
View File
@@ -539,6 +539,7 @@ pub async fn chat_completions(
let bootstrap_room = bootstrap_room.expect("PD dispatch implies a resolved bootstrap room");
let prefill_url = worker.url.clone();
let prefill_protocol = worker.protocol();
let prefill_breaker = Arc::clone(&worker.breaker);
let prefill_headers = headers.clone();
let prefill_body = outgoing_body.clone();
@@ -555,6 +556,7 @@ pub async fn chat_completions(
match prefill_proxy
.forward_json_to(
&prefill_url,
prefill_protocol,
&prefill_breaker,
"/v1/chat/completions",
&prefill_headers,
@@ -588,6 +590,7 @@ pub async fn chat_completions(
Box::new((decode_guard, decode_active_guard, make_duration_guard()));
let fetch = ctx.proxy.forward_streaming_to(
&decode_worker.url,
decode_worker.protocol(),
&decode_worker.breaker,
"/v1/chat/completions",
&headers,
@@ -605,6 +608,7 @@ pub async fn chat_completions(
let _decode_hold = (decode_guard, decode_active_guard);
let fetch = ctx.proxy.forward_json_to(
&decode_worker.url,
decode_worker.protocol(),
&decode_worker.breaker,
"/v1/chat/completions",
&headers,
@@ -624,6 +628,7 @@ pub async fn chat_completions(
Box::new((guard, active_guard, make_duration_guard()));
let fetch = ctx.proxy.forward_streaming_to(
&worker.url,
worker.protocol(),
&worker.breaker,
"/v1/chat/completions",
&headers,
@@ -653,6 +658,7 @@ pub async fn chat_completions(
let _holds: (LoadGuard, _) = (guard, active_guard);
let fetch = ctx.proxy.forward_json_to(
&worker.url,
worker.protocol(),
&worker.breaker,
"/v1/chat/completions",
&headers,
experimental/sgl-router/src/workers/manager.rs
+11 -10
View File
@@ -82,11 +82,11 @@ fn dials_cleartext(worker_url: &str) -> Option<bool> {
/// that risk.
///
/// [`WireProtocol::Http1`] is the fallback for everything else, and it does
/// mean HTTP/1.1 on the wire: reqwest is built here without its `http2`
/// feature, so the forwarding client advertises only `http/1.1` even on TLS.
/// An `https://` worker running `--enable-http2` therefore stays on HTTP/1.1
/// — correct, because h2c cannot be sent to a TLS endpoint either way, but
/// not the ALPN upgrade the flag might suggest. See [`WireProtocol`].
/// not mean "HTTP/1.1 on the wire". It selects the negotiating client, which
/// advertises ALPN `h2, http/1.1`, so an `https://` worker running
/// `--enable-http2` reaches HTTP/2 over TLS on its own — the correct outcome,
/// arrived at by negotiation rather than by assumption. Only cleartext workers
/// need prior-knowledge h2c. See [`WireProtocol`].
fn resolve_protocol(enable_http2: Option<bool>, cleartext: Option<bool>) -> WireProtocol {
match (enable_http2, cleartext) {
(Some(true), Some(true)) => WireProtocol::H2c,
@@ -449,12 +449,12 @@ fn log_protocol_resolution(worker_url: &str, enable_http2: Option<bool>, clearte
worker_url = %worker_url,
"/server_info reports --enable-http2 on a cleartext worker; forwarding over h2c",
),
// A TLS worker. h2c is unsendable there and the client does not
// negotiate, so this worker stays on HTTP/1.1.
// A TLS worker. h2c is unsendable there, but the negotiating client
// advertises ALPN h2, so a TLS engine still reaches HTTP/2 on its own.
(Some(true), Some(false)) => tracing::info!(
worker_url = %worker_url,
"/server_info reports --enable-http2 on a TLS worker; \
forwarding over HTTP/1.1",
"/server_info reports --enable-http2 on a TLS worker; using the \
negotiating client, which reaches HTTP/2 over TLS via ALPN",
),
// `dials_cleartext` could not parse the URL. Reaching this at all means
// `/server_info` answered over a URL the scheme check then rejected, so
@@ -473,7 +473,8 @@ fn log_protocol_resolution(worker_url: &str, enable_http2: Option<bool>, clearte
// revisiting it, so this reading is the only one it will ever get.
(None, _) => tracing::info!(
worker_url = %worker_url,
"no --enable-http2 reading from /server_info; forwarding over HTTP/1.1",
"no --enable-http2 reading from /server_info; using the negotiating \
client (HTTP/1.1 in cleartext)",
),
// The engine explicitly disabled it. Nothing to explain.
(Some(false), _) => {}
experimental/sgl-router/src/workers/worker.rs
+9 -9
View File
@@ -13,19 +13,19 @@ use std::time::Instant;
/// Fixed for the worker's lifetime: it is derived by `manager::resolve_protocol`
/// from the engine's `--enable-http2` launch flag and the dialed URL scheme,
/// neither of which changes while the process runs. The asymmetry that drives
/// the default: HTTP/1.1 is accepted by every engine, while h2c is
/// prior-knowledge only and fails outright against an engine that does not
/// the default: the negotiating client is accepted by every engine, while h2c
/// is prior-knowledge only and fails outright against an engine that does not
/// serve it.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum WireProtocol {
/// HTTP/1.1, in cleartext and over TLS alike. Safe for every engine, so it
/// is also the fallback.
/// The negotiating client. Safe for every engine, so it is also the
/// fallback.
///
/// Not ALPN-negotiated: `Cargo.toml` builds reqwest with
/// `default-features = false` and does not enable `http2`, so the
/// forwarding client advertises only `http/1.1` and a TLS engine running
/// `--enable-http2` still gets HTTP/1.1. Enabling that feature is what
/// would make this variant negotiate.
/// HTTP/1.1 in cleartext, ALPN-negotiated over TLS: this crate enables
/// reqwest's `http2` feature (see `Cargo.toml`), so the client advertises
/// `h2, http/1.1` and a TLS engine running `--enable-http2` reaches HTTP/2
/// on its own. Dropping that feature silently reduces this variant to
/// HTTP/1.1 everywhere.
#[default]
Http1,
/// Cleartext HTTP/2 with prior knowledge (h2c). Used only when a worker
experimental/sgl-router/tests/e2e/k8s_integration/Dockerfile.fake_worker
+1 -1
View File
@@ -1,6 +1,6 @@
FROM python:3.12-slim
WORKDIR /app
RUN pip install --no-cache-dir fastapi uvicorn
RUN pip install --no-cache-dir fastapi uvicorn granian
COPY fake_worker.py .
EXPOSE 30000
CMD ["python", "fake_worker.py"]
experimental/sgl-router/tests/e2e/k8s_integration/fake_worker.py
+51 -4
View File
@@ -2,9 +2,21 @@
Responds to:
GET /health -> {"status": "ok"}
GET /server_info -> {"served_model_name": MODEL_ID}
GET /server_info -> {"served_model_name": MODEL_ID, ...}
GET /v1/models -> list with a single MODEL_ID model entry
POST /v1/chat/completions -> echoes the last user message back
POST /v1/chat/completions -> echoes the last user message back, plus
the HTTP version the request arrived on
Set `FAKE_WORKER_HTTP2=1` to imitate an engine launched with
`--enable-http2`: `/server_info` advertises the flag and the app is served by
Granian in `HTTPModes.auto`, which is what the real engine runs, so one port
serves cleartext h2c alongside HTTP/1.1. The default is uvicorn, which speaks
HTTP/1.1 only.
`x_http_version` on the chat response is the load-bearing part for
`test_h2c_forwarding.py`: a chat completion returns 200 over either protocol,
so without the worker reporting what it actually received, an h2c test passes
whether or not h2c was used.
"""
from __future__ import annotations
@@ -17,6 +29,16 @@ from fastapi import FastAPI, Request
app = FastAPI()
MODEL_ID = os.environ.get("MODEL_ID", "tiny")
# Normalised before comparing: a manifest that writes the Python-idiomatic
# "False" must not silently turn this worker into a Granian/h2c one, which
# would fail test_h2c_forwarding with a message about a router bug.
ENABLE_HTTP2 = os.environ.get("FAKE_WORKER_HTTP2", "").strip().lower() not in (
"",
"0",
"false",
"no",
"off",
)
@app.get("/health")
@@ -27,8 +49,12 @@ async def health():
@app.get("/server_info")
async def server_info():
# The sgl-router worker manager fetches this on every Added event and
# uses `served_model_name` to populate the registry's model index.
return {"served_model_name": MODEL_ID}
# uses `served_model_name` to populate the registry's model index, and
# `enable_http2` to resolve the worker's forwarding protocol.
info = {"served_model_name": MODEL_ID}
if ENABLE_HTTP2:
info["enable_http2"] = True
return info
@app.get("/v1/models")
@@ -55,6 +81,11 @@ async def chat_completions(request: Request):
"id": "chatcmpl-mock",
"object": "chat.completion",
"model": payload.get("model", MODEL_ID),
# Non-standard, and deliberately so: the router returns the upstream
# body verbatim (`proxy::forward_*` hands back `resp.bytes()`), so this
# is how a test on the other side of the router learns which protocol
# the forward leg actually used. "1.1" or "2".
"x_http_version": request.scope.get("http_version"),
"choices": [
{
"index": 0,
@@ -70,4 +101,20 @@ async def chat_completions(request: Request):
if __name__ == "__main__":
if ENABLE_HTTP2:
# Mirrors the engine's own server (`_run_granian_server` in
# sglang/srt/entrypoints/http_server.py): HTTPModes.auto dispatches per
# connection on the first bytes, so h2c prior-knowledge and HTTP/1.1
# share one cleartext port.
from granian import Granian
from granian.constants import HTTPModes, Interfaces
Granian(
target="fake_worker:app",
address="0.0.0.0",
port=30000,
interface=Interfaces.ASGI,
http=HTTPModes.auto,
).serve()
else:
uvicorn.run(app, host="0.0.0.0", port=30000)
experimental/sgl-router/tests/e2e/k8s_integration/test_h2c_forwarding.py
+198
View File
@@ -0,0 +1,198 @@
"""E2E: the router forwards to an h2c-capable worker over cleartext HTTP/2.
The in-process tests (`tests/proxy/h2c_forward.rs`, `inbound_h2c.rs`) already
drive real HTTP/2 sockets, and dropping reqwest's `http2` feature fails the
build outright, so neither the client nor the framing needs covering again
here. What no in-process test can assemble is the *chain*: a worker discovered
through a real EndpointSlice, introspected over the network, resolved to
`WireProtocol::H2c` from its own `/server_info`, and then actually forwarded to
over h2c.
The fleet is deliberately mixed. `setup.sh` leaves three uvicorn workers
(HTTP/1.1 only) behind the `app=sglang` Service; this module adds one Granian
worker reporting `enable_http2: true` to the same Service, so both protocols
must be in use simultaneously. That is the e2e form of the per-worker-protocol
property: a router that resolved one protocol fleet-wide would either fail
against the h2c worker or break the three HTTP/1.1 ones, and either way this
test fails.
"""
from __future__ import annotations
import httpx
import pytest
from conftest import (
NAMESPACE,
_apply_from_stdin,
_kubectl,
_poll_until,
_wait_for_deployment_ready,
logger,
)
H2C_DEPLOYMENT = "fake-worker-h2c"
# Round-robin over a 4-worker pool: 12 requests give every worker ~3 turns, so
# a miss means a routing or resolution failure rather than an unlucky draw.
_PROBE_REQUESTS = 12
# Kept low enough that a whole probe round (12 x 5 s worst case) fits inside the
# 90 s poll budget below. A fake worker answers instantly; a request that needs
# more than 5 s is already a failure, and letting a round outlast its own poll
# would make that timeout non-binding.
_CHAT_TIMEOUT = 5.0
_CONVERGE_TIMEOUT = 90
_H2C_WORKER_MANIFEST = f"""
apiVersion: apps/v1
kind: Deployment
metadata:
name: {H2C_DEPLOYMENT}
namespace: {NAMESPACE}
spec:
replicas: 1
selector:
matchLabels:
app: sglang-h2c
template:
metadata:
labels:
app: sglang-h2c
spec:
containers:
- name: worker
image: sgl-router-fake-worker:e2e
imagePullPolicy: Never
env:
- name: FAKE_WORKER_HTTP2
value: "1"
- name: MODEL_ID
value: "tiny"
ports:
- containerPort: 30000
readinessProbe:
httpGet:
path: /health
port: 30000
initialDelaySeconds: 2
periodSeconds: 3
---
apiVersion: v1
kind: Service
metadata:
name: {H2C_DEPLOYMENT}
namespace: {NAMESPACE}
# The router watches ENDPOINTSLICES whose labels match `--selector
# app=sglang`, and Kubernetes mirrors a Service's labels onto the slices it
# manages -- so this label, not the pods', is what puts these workers in the
# router's view.
labels:
app: sglang
spec:
# Pods are labelled `app: sglang-h2c`, deliberately NOT `app: sglang`: the
# fake-worker Deployment's selector is a bare `app=sglang`, so sharing that
# label would put these pods inside another controller's selector and into
# the HTTP/1.1 Service as well.
selector:
app: sglang-h2c
ports:
- port: 30000
targetPort: 30000
"""
@pytest.fixture(scope="module")
def h2c_worker(k8s_cluster):
"""Add one Granian/h2c worker, behind its own Service, to the router's view.
Its own Service rather than the existing one: the router selects
EndpointSlices, so a second Service labelled `app: sglang` is watched just
the same, while its pods stay out of the `fake-worker` Deployment's bare
`app=sglang` selector. Torn down afterwards so the suite's other modules
see the three-worker fleet they expect.
"""
_apply_from_stdin(_H2C_WORKER_MANIFEST)
try:
_wait_for_deployment_ready(H2C_DEPLOYMENT)
yield
finally:
for kind in ("deployment", "service"):
_kubectl(
"delete",
kind,
H2C_DEPLOYMENT,
"-n",
NAMESPACE,
"--ignore-not-found",
"--wait=true",
check=False,
)
def _chat(router_url: str, content: str) -> httpx.Response:
return httpx.post(
f"{router_url}/v1/chat/completions",
json={
"model": "tiny",
"messages": [{"role": "user", "content": content}],
"stream": False,
},
timeout=_CHAT_TIMEOUT,
)
def _observed_protocols(router_url: str, *, strict: bool) -> set[str]:
"""Fan out round-robin and collect the HTTP version each worker saw.
`x_http_version` is reported by the worker itself, not inferred from the
client side: the test's own connection to the router is a separate hop, so
only the worker can say what the forward leg used. Distinct content per
request keeps any content-derived routing from collapsing onto one worker.
`strict=False` while converging. The router runs `--cb-threshold 1`
(manifests/router.yaml), so one refused connection to the still-starting h2c
pod opens its breaker and round-robin hands back a 502 for that turn. That
is precisely what the poll is meant to wait out — and `conftest._poll_until`
retries only transport-level errors, so an `AssertionError` raised here
would escape the retry budget and fail the test on the first blip. Skip
non-200s while converging; assert on them once converged.
"""
seen: set[str] = set()
for i in range(_PROBE_REQUESTS):
r = _chat(router_url, f"h2c-probe-{i}")
if r.status_code != 200:
if strict:
raise AssertionError(f"request {i} failed {r.status_code}: {r.text}")
continue
version = r.json().get("x_http_version")
# Fatal either way: this is a stale fake-worker image or a router that
# stopped returning the upstream body verbatim, neither of which a retry
# fixes, and without it the test cannot tell h2c from HTTP/1.1 at all.
assert version is not None, (
"worker did not report `x_http_version` — the fake-worker image is "
"stale, or the router stopped returning the upstream body verbatim; "
"either way this test cannot tell h2c from HTTP/1.1"
)
seen.add(version)
logger.info("protocols observed across %d requests: %s", _PROBE_REQUESTS, seen)
return seen
def test_router_forwards_over_h2c_to_an_http2_worker(router_url, h2c_worker):
"""A worker advertising `enable_http2` is reached over HTTP/2, and the
HTTP/1.1 workers alongside it keep their own protocol."""
# The router must first see the new pod's EndpointSlice entry and
# introspect it; until then every response comes back "1.1".
_poll_until(
lambda: "2" in _observed_protocols(router_url, strict=False),
"router forwards to the h2c worker over HTTP/2",
timeout=_CONVERGE_TIMEOUT,
interval=5,
)
seen = _observed_protocols(router_url, strict=True)
assert "2" in seen, f"expected an HTTP/2 forward, saw {seen}"
assert "1.1" in seen, (
f"expected the three uvicorn workers to stay on HTTP/1.1, saw {seen}; "
"a fleet-wide protocol would have taken them with it"
)
experimental/sgl-router/tests/proxy/chat_routing.rs
+7 -1
View File
@@ -12,7 +12,7 @@ use sgl_router::server::app::build_router;
use sgl_router::server::app_context::AppContext;
use sgl_router::server::routes::chat::MAX_CHAT_BODY_BYTES;
use sgl_router::tokenizer::TokenizerRegistry;
use sgl_router::workers::{Worker, WorkerRegistry};
use sgl_router::workers::{WireProtocol, Worker, WorkerRegistry};
use axum::body::Body;
use axum::http::{Request, StatusCode};
@@ -839,6 +839,7 @@ async fn forward_json_to_records_failure_on_body_drop() {
let res: Result<_, ApiError> = proxy
.forward_json_to(
&worker.url,
WireProtocol::Http1,
&breaker,
"/v1/chat/completions",
&headers,
@@ -895,6 +896,7 @@ async fn forward_json_to_records_success_only_after_body_completes() {
let res: Result<_, ApiError> = proxy
.forward_json_to(
&ok_worker.url,
WireProtocol::Http1,
&breaker,
"/v1/chat/completions",
&headers,
@@ -945,6 +947,7 @@ async fn forward_streaming_to_records_failure_on_mid_stream_drop() {
let res: Result<_, ApiError> = proxy
.forward_streaming_to(
&worker.url,
WireProtocol::Http1,
&breaker,
"/v1/chat/completions",
&headers,
@@ -995,6 +998,7 @@ async fn forward_json_to_records_failure_on_5xx() {
let _: Result<_, ApiError> = proxy
.forward_json_to(
&worker.url,
WireProtocol::Http1,
&breaker,
"/v1/chat/completions",
&headers,
@@ -1028,6 +1032,7 @@ async fn forward_json_to_rejects_when_breaker_open() {
let res = proxy
.forward_json_to(
&worker.url,
WireProtocol::Http1,
&breaker,
"/v1/chat/completions",
&headers,
@@ -1065,6 +1070,7 @@ async fn forward_json_to_malformed_url_returns_worker_misconfigured_and_trips_br
let res = proxy
.forward_json_to(
"not-a-url",
WireProtocol::Http1,
&breaker,
"/v1/chat/completions",
&headers,
experimental/sgl-router/tests/proxy/h2c_forward.rs
+195
View File
@@ -0,0 +1,195 @@
// SPDX-FileCopyrightText: Copyright (c) 2026 The SGLang Authors
// SPDX-License-Identifier: Apache-2.0
//! Cleartext-HTTP/2 (h2c) forwarding tests for [`Proxy`].
//!
//! These spin up an **HTTP/2-only** server (hyper's `http2::Builder`, no
//! HTTP/1.1 path) and drive `forward_json_to` against it with an explicit
//! per-request [`WireProtocol`]. Together the two tests prove what a value-only
//! unit test cannot: that the proxy's h2c client genuinely speaks HTTP/2 on the
//! wire when a request selects [`WireProtocol::H2c`] (not just that the value
//! was threaded through), and that the HTTP/1.1 client cannot reach an h2c
//! worker — so a regression that dropped the `http2` Cargo feature, removed
//! `http2_prior_knowledge()`, or mismatched `build_client`'s arms would fail
//! here rather than slip through. They also pin the per-worker design: the
//! protocol is chosen per `forward_json_to` call, not committed fleet-wide.
use std::convert::Infallible;
use std::sync::Arc;
use std::time::Duration;
use bytes::Bytes;
use http_body_util::{BodyExt, Full, StreamBody};
use hyper::body::Frame;
use hyper::server::conn::http2;
use hyper::service::service_fn;
use hyper::{Request, Response};
use hyper_util::rt::{TokioExecutor, TokioIo};
use sgl_router::health::circuit_breaker::CircuitBreaker;
use sgl_router::proxy::Proxy;
use sgl_router::workers::WireProtocol;
use tokio::net::TcpListener;
/// Serve HTTP/2 only. `http2::Builder::serve_connection` speaks the HTTP/2
/// framing protocol with no HTTP/1.1 fallback, so a client that does not
/// send the HTTP/2 connection preface cannot complete a request. Returns the
/// base URL; the accept loop is aborted when the test runtime shuts down.
async fn spawn_h2c_only_server() -> String {
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
let addr = listener.local_addr().unwrap();
tokio::spawn(async move {
while let Ok((stream, _)) = listener.accept().await {
tokio::spawn(async move {
let _ = http2::Builder::new(TokioExecutor::new())
.serve_connection(
TokioIo::new(stream),
service_fn(|_req: Request<hyper::body::Incoming>| async {
Ok::<_, Infallible>(Response::new(Full::new(Bytes::from_static(
b"{\"ok\":true}",
))))
}),
)
.await;
});
}
});
format!("http://{addr}")
}
#[tokio::test]
async fn h2c_client_reaches_http2_only_worker() {
let url = spawn_h2c_only_server().await;
let proxy = Proxy::new(Duration::from_secs(5)).unwrap();
let breaker = CircuitBreaker::new();
// Select h2c per request, as the chat handler does for a worker whose
// `/server_info` reported --enable-http2 on a cleartext URL.
let resp = proxy
.forward_json_to(
&url,
WireProtocol::H2c,
&breaker,
"/v1/chat/completions",
&axum::http::HeaderMap::new(),
Bytes::from_static(b"{}"),
)
.await
.expect("h2c client must reach an HTTP/2-only worker");
assert_eq!(resp.status(), 200);
}
#[tokio::test]
async fn http1_client_cannot_reach_http2_only_worker() {
let url = spawn_h2c_only_server().await;
let proxy = Proxy::new(Duration::from_secs(5)).unwrap();
let breaker = CircuitBreaker::new();
// The HTTP/1.1 client never sends the HTTP/2 preface, so the h2c-only
// server cannot serve it. This is what makes selecting the protocol
// meaningful: Http1 and H2c are different protocols on the wire, not the
// same client pointed at the same endpoint.
let res = proxy
.forward_json_to(
&url,
WireProtocol::Http1,
&breaker,
"/v1/chat/completions",
&axum::http::HeaderMap::new(),
Bytes::from_static(b"{}"),
)
.await;
assert!(
res.is_err(),
"HTTP/1.1 client must not complete a request against an HTTP/2-only worker, got {res:?}",
);
}
/// Serve HTTP/2 only, answering with a multi-frame SSE body. Each `data:`
/// chunk is its own HTTP/2 DATA frame, which is the framing the real engine
/// produces for a streaming generation.
async fn spawn_h2c_only_sse_server() -> String {
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
let addr = listener.local_addr().unwrap();
tokio::spawn(async move {
while let Ok((stream, _)) = listener.accept().await {
tokio::spawn(async move {
let _ = http2::Builder::new(TokioExecutor::new())
.serve_connection(
TokioIo::new(stream),
service_fn(|_req: Request<hyper::body::Incoming>| async {
let chunks: Vec<Result<Frame<Bytes>, Infallible>> = vec![
Ok(Frame::data(Bytes::from_static(b"data: {\"i\":0}\n\n"))),
Ok(Frame::data(Bytes::from_static(b"data: {\"i\":1}\n\n"))),
Ok(Frame::data(Bytes::from_static(b"data: [DONE]\n\n"))),
];
let body = StreamBody::new(futures::stream::iter(chunks));
Ok::<_, Infallible>(
Response::builder()
.header("content-type", "text/event-stream")
.body(body)
.unwrap(),
)
}),
)
.await;
});
}
});
format!("http://{addr}")
}
/// The streaming forward — the path every chat generation actually takes — must
/// work over h2c, and must deliver the whole multi-frame body.
///
/// `forward_streaming_to` differs from `forward_json_to` in ways HTTP/2 reaches
/// differently: it omits the request timeout, and it hands `bytes_stream()` to
/// the SSE pump rather than buffering. A break confined to SSE-over-h2c — a
/// truncated body, a stall, a mid-stream reset surfacing as success — leaves
/// the buffered tests green, so cover it directly.
#[tokio::test]
async fn h2c_client_streams_sse_from_http2_only_worker() {
let url = spawn_h2c_only_sse_server().await;
let proxy = Proxy::new(Duration::from_secs(5)).unwrap();
let breaker = Arc::new(CircuitBreaker::new());
let first_byte_seen = Arc::new(std::sync::atomic::AtomicBool::new(false));
let flag = Arc::clone(&first_byte_seen);
let resp = proxy
.forward_streaming_to(
&url,
WireProtocol::H2c,
&breaker,
"/v1/chat/completions",
&axum::http::HeaderMap::new(),
Bytes::from_static(b"{}"),
None,
Some(Box::new(move || {
flag.store(true, std::sync::atomic::Ordering::SeqCst);
})),
None,
)
.await
.expect("h2c client must stream from an HTTP/2-only worker");
assert_eq!(resp.status(), 200);
let body = resp
.into_body()
.collect()
.await
.expect("streaming body must complete over h2c")
.to_bytes();
let text = String::from_utf8(body.to_vec()).unwrap();
// Every frame arrives, in order — not just the first.
assert!(text.contains("\"i\":0"), "missing first chunk: {text}");
assert!(text.contains("\"i\":1"), "missing second chunk: {text}");
assert!(
text.contains("[DONE]"),
"stream truncated before DONE: {text}"
);
assert!(
first_byte_seen.load(std::sync::atomic::Ordering::SeqCst),
"on_first_byte must fire for an h2c stream (TTFT accounting depends on it)",
);
}
experimental/sgl-router/tests/proxy/inbound_h2c.rs
+116
View File
@@ -0,0 +1,116 @@
// SPDX-FileCopyrightText: Copyright (c) 2026 The SGLang Authors
// SPDX-License-Identifier: Apache-2.0
//! Inbound cleartext-HTTP/2 (h2c) listener tests for the router's own server.
//!
//! Where `h2c_forward.rs` proves the router's *outbound* client speaks h2c to
//! an HTTP/2-only worker, these prove the *inbound* side: the router's
//! `axum::serve` listener accepts an h2c prior-knowledge client on the same
//! cleartext port it serves HTTP/1.1 on, auto-negotiating per connection.
//!
//! Protocol negotiation happens at the connection layer, below the tower
//! service — so unlike the `oneshot` tests in `chat_routing.rs`, these must
//! drive a real socket via `axum::serve` (mirroring `main.rs`).
//!
//! What actually compiles the listener's h2 path is `hyper-util/http2`, reached
//! through `server-auto`, and several dependencies enable it. So these tests do
//! NOT fail if axum's own `http2` feature is dropped — verified by removing it.
//! Their job is the property an operator depends on, whatever the feature graph
//! happens to look like: one cleartext port serving both h2c prior-knowledge
//! and HTTP/1.1. That is what would break if a dependency change silently took
//! `hyper-util/http2` away.
use std::sync::Arc;
use std::time::Duration;
use sgl_router::config::PolicyKind;
use sgl_router::policies::factory::build_registry_with_defaults as build_policy_registry;
use sgl_router::proxy::Proxy;
use sgl_router::server::app::build_router;
use sgl_router::server::app_context::AppContext;
use sgl_router::tokenizer::TokenizerRegistry;
use sgl_router::workers::WorkerRegistry;
use axum::http::Version;
const TEST_TIMEOUT: Duration = Duration::from_secs(5);
fn build_ctx() -> Arc<AppContext> {
// Reuse the shared fixture rather than restating the whole `Config`: this
// test is about the listener, not the routing policy, and a local literal
// would be one more site to edit every time `ModelConfig` gains a field.
let mut cfg = crate::common::cache_aware_fixture::config();
cfg.model.policy = PolicyKind::RoundRobin;
cfg.model.cache_aware = None;
let tokenizers = Arc::new(TokenizerRegistry::load_from_config(&cfg).unwrap());
let registry = Arc::new(WorkerRegistry::default());
let policies = Arc::new(build_policy_registry(&cfg).unwrap());
let proxy = Arc::new(Proxy::new(TEST_TIMEOUT).unwrap());
Arc::new(AppContext::new(cfg, tokenizers, proxy, registry, policies))
}
/// Spawn the real router (`build_router`) behind `axum::serve` on an ephemeral
/// port — the exact serve path used in `main.rs`. `/healthz` returns 200
/// unconditionally, so no worker is needed. Returns the base URL; the accept
/// loop is dropped when the test runtime shuts down.
async fn spawn_router() -> String {
let ctx = build_ctx();
ctx.mark_ready();
let app = build_router(ctx);
let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
let addr = listener.local_addr().unwrap();
tokio::spawn(async move {
let _ = axum::serve(listener, app).await;
});
format!("http://{addr}")
}
#[tokio::test]
async fn inbound_accepts_h2c_prior_knowledge() {
let base = spawn_router().await;
// `http2_prior_knowledge()` sends the HTTP/2 connection preface directly
// over cleartext (no ALPN, no h1 upgrade) — the same way a service-mesh
// sidecar dials h2c. The listener must recognize the preface and serve h2.
let client = reqwest::Client::builder()
.http2_prior_knowledge()
.build()
.unwrap();
let resp = client
.get(format!("{base}/healthz"))
.send()
.await
.expect("h2c prior-knowledge client must reach the router listener");
assert_eq!(resp.status(), 200);
assert_eq!(
resp.version(),
Version::HTTP_2,
"listener must negotiate HTTP/2 for an h2c prior-knowledge client",
);
}
#[tokio::test]
async fn inbound_still_accepts_http1() {
let base = spawn_router().await;
// The default reqwest client speaks HTTP/1.1 over cleartext. Enabling h2c
// must not break existing HTTP/1.1 callers (load balancers, probes, curl)
// — the auto builder serves both on the same port.
let client = reqwest::Client::new();
let resp = client
.get(format!("{base}/healthz"))
.send()
.await
.expect("HTTP/1.1 client must still reach the router listener");
assert_eq!(resp.status(), 200);
assert_eq!(
resp.version(),
Version::HTTP_11,
"an HTTP/1.1 client must keep negotiating HTTP/1.1 on the same port",
);
}
experimental/sgl-router/tests/proxy/main.rs
+3
View File
@@ -16,9 +16,12 @@ mod chat_routing;
mod external_indexer_routing;
mod failover;
mod graceful_shutdown;
mod h2c_forward;
mod header_forwarding;
mod inbound_h2c;
mod pd_bootstrap_injection;
mod pd_pool_isolation;
mod pd_protocol_binding;
mod radix_tree_routing;
mod roundrobin_input_ids;
mod shared_prefill_admission;
experimental/sgl-router/tests/proxy/pd_protocol_binding.rs
+260
View File
@@ -0,0 +1,260 @@
// SPDX-FileCopyrightText: Copyright (c) 2026 The SGLang Authors
// SPDX-License-Identifier: Apache-2.0
//! Binds protocol *resolution* to protocol *use*, across the PD split.
//!
//! Everywhere else the two halves are tested apart: the manager tests assert
//! what lands on the registry, and `h2c_forward.rs` passes a `WireProtocol` to
//! the proxy by hand. Nothing asserts that the protocol a worker resolved to is
//! the one its own forward actually uses — and in the PD arm of
//! `chat_completions` that join is three separate expressions, a
//! `prefill_protocol` captured before a `tokio::spawn` plus two live
//! `decode_worker.protocol()` reads. Passing the wrong one of those compiles,
//! and every other test in the suite stays green.
//!
//! So make the two workers disagree and let the wire enforce it: the prefill
//! mock speaks **HTTP/2 only**, the decode mock speaks **HTTP/1.1 only**, and
//! each is registered with the matching protocol. Any mix-up sends a client at
//! a server that cannot answer it. This is also why neither mock can be the
//! shared `MockWorker` — that one runs on `axum::serve`, which answers both
//! protocols and would pass no matter which was selected.
use std::convert::Infallible;
use std::sync::{Arc, Mutex};
use std::time::Duration;
use axum::body::Body;
use axum::http::{Request, StatusCode};
use bytes::Bytes;
use http_body_util::{BodyExt, Full};
use hyper::server::conn::{http1, http2};
use hyper::service::service_fn;
use hyper::Response as HyperResponse;
use hyper_util::rt::{TokioExecutor, TokioIo};
use sgl_router::config::{
ActiveLoadConfig, Config, DiscoveryBackend, ModelConfig, ObservabilityConfig, PolicyKind,
ProxyConfig, ServerConfig, StaticUrlsDiscoveryConfig,
};
use sgl_router::discovery::{ModelId, WorkerId, WorkerMode, WorkerSpec};
use sgl_router::policies::factory::build_registry_with_defaults;
use sgl_router::proxy::Proxy;
use sgl_router::server::app::build_router;
use sgl_router::server::app_context::AppContext;
use sgl_router::tokenizer::TokenizerRegistry;
use sgl_router::workers::{WireProtocol, WorkerRegistry};
use tokio::net::TcpListener;
use tower::ServiceExt;
/// A chat-completions response shaped enough for the handler to return 200.
fn chat_completion_json() -> Bytes {
Bytes::from(
serde_json::json!({
"id": "chatcmpl-test",
"object": "chat.completion",
"created": 0,
"model": "tiny",
"choices": [{
"index": 0,
"message": {"role": "assistant", "content": "ok"},
"finish_reason": "stop"
}],
"usage": {"prompt_tokens": 1, "completion_tokens": 1, "total_tokens": 2}
})
.to_string(),
)
}
/// Serve HTTP/2 only, recording that a request body arrived. An HTTP/1.1
/// client cannot complete a request here — it never sends the HTTP/2 preface.
async fn spawn_h2_only_worker(hits: Arc<Mutex<usize>>) -> String {
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
let addr = listener.local_addr().unwrap();
tokio::spawn(async move {
while let Ok((stream, _)) = listener.accept().await {
let hits = Arc::clone(&hits);
tokio::spawn(async move {
let _ = http2::Builder::new(TokioExecutor::new())
.serve_connection(
TokioIo::new(stream),
service_fn(move |_req| {
let hits = Arc::clone(&hits);
async move {
*hits.lock().unwrap() += 1;
Ok::<_, Infallible>(HyperResponse::new(Full::new(
chat_completion_json(),
)))
}
}),
)
.await;
});
}
});
format!("http://{addr}")
}
/// Serve HTTP/1.1 only. `http1::Builder` speaks no HTTP/2, so an h2c client
/// sending the preface cannot be served here.
async fn spawn_http1_only_worker(hits: Arc<Mutex<usize>>) -> String {
let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
let addr = listener.local_addr().unwrap();
tokio::spawn(async move {
while let Ok((stream, _)) = listener.accept().await {
let hits = Arc::clone(&hits);
tokio::spawn(async move {
let _ = http1::Builder::new()
.serve_connection(
TokioIo::new(stream),
service_fn(move |_req| {
let hits = Arc::clone(&hits);
async move {
*hits.lock().unwrap() += 1;
Ok::<_, Infallible>(HyperResponse::new(Full::new(
chat_completion_json(),
)))
}
}),
)
.await;
});
}
});
format!("http://{addr}")
}
fn config() -> Config {
Config {
server: ServerConfig {
host: "0".into(),
port: 0,
},
observability: ObservabilityConfig::default(),
model: ModelConfig {
id: "tiny".into(),
tokenizer_path: "tests/fixtures/tiny_tokenizer.json".into(),
policy: PolicyKind::RoundRobin,
decode_policy: Default::default(),
bucket_config: None,
circuit_breaker: None,
cache_aware: None,
sticky: None,
affinity: None,
fused: None,
eligibility: None,
},
discovery: DiscoveryBackend::StaticUrls(StaticUrlsDiscoveryConfig {
urls: vec!["http://placeholder:0".into()],
}),
proxy: ProxyConfig::default(),
active_load: ActiveLoadConfig::default(),
}
}
/// Register both workers with their own resolved protocol, the way
/// `manager::register_one` does after introspecting `/server_info`.
fn build_ctx(prefill_url: String, decode_url: String) -> Arc<AppContext> {
let cfg = config();
let tokenizers = Arc::new(TokenizerRegistry::load_from_config(&cfg).unwrap());
let registry = Arc::new(WorkerRegistry::default());
let prefill_id = WorkerId("p1".into());
let decode_id = WorkerId("d1".into());
// The two disagree on purpose. This is the state a mixed fleet reaches
// when only some engines run with --enable-http2.
registry
.add_with_cb(
WorkerSpec {
id: prefill_id.clone(),
url: prefill_url,
mode: WorkerMode::Prefill,
model_ids: vec![ModelId("tiny".into())],
bootstrap_port: Some(8997),
},
None,
WireProtocol::H2c,
)
.unwrap();
registry
.add_with_cb(
WorkerSpec {
id: decode_id.clone(),
url: decode_url,
mode: WorkerMode::Decode,
model_ids: vec![ModelId("tiny".into())],
bootstrap_port: None,
},
None,
WireProtocol::Http1,
)
.unwrap();
let policies = Arc::new(build_registry_with_defaults(&cfg).unwrap());
let proxy = Arc::new(Proxy::new(Duration::from_secs(5)).unwrap());
Arc::new(AppContext::new(cfg, tokenizers, proxy, registry, policies))
}
fn chat_request() -> Request<Body> {
Request::builder()
.method("POST")
.uri("/v1/chat/completions")
.header("content-type", "application/json")
.body(Body::from(
serde_json::to_vec(&serde_json::json!({
"model": "tiny",
"messages": [{"role": "user", "content": "hi"}],
"stream": false
}))
.unwrap(),
))
.unwrap()
}
/// Each PD leg must forward over the protocol *its own* worker resolved.
///
/// The decode leg is awaited, so a protocol mix-up there fails the response
/// outright. The prefill leg is detached, so its mix-up shows up as a body that
/// never arrives — poll for it rather than reading once.
#[tokio::test]
async fn pd_legs_each_use_their_own_workers_protocol() {
let prefill_hits = Arc::new(Mutex::new(0usize));
let decode_hits = Arc::new(Mutex::new(0usize));
let prefill_url = spawn_h2_only_worker(Arc::clone(&prefill_hits)).await;
let decode_url = spawn_http1_only_worker(Arc::clone(&decode_hits)).await;
let app = build_router(build_ctx(prefill_url, decode_url));
let res = app.oneshot(chat_request()).await.unwrap();
// Decode answered, so the decode leg used HTTP/1.1 — had it been handed the
// prefill worker's H2c, this HTTP/1.1-only server could not have replied.
assert_eq!(
res.status(),
StatusCode::OK,
"decode leg must forward over the decode worker's own protocol (HTTP/1.1)",
);
let body = res.into_body().collect().await.unwrap().to_bytes();
assert!(
!body.is_empty(),
"decode response body must reach the client",
);
// Prefill is spawn-and-forget; it races the response back to the client.
let reached = tokio::time::timeout(Duration::from_secs(3), async {
loop {
if *prefill_hits.lock().unwrap() > 0 {
return true;
}
tokio::time::sleep(Duration::from_millis(10)).await;
}
})
.await;
assert!(
reached.is_ok(),
"prefill leg must forward over the prefill worker's own protocol (h2c); \
an HTTP/1.1 client cannot reach this HTTP/2-only worker",
);
assert_eq!(
*decode_hits.lock().unwrap(),
1,
"decode worker should be hit exactly once",
);
}