Files
sglang/sgl-router/src/routers/http/router.rs

1624 lines
62 KiB
Rust

use crate::config::types::RetryConfig;
use crate::core::{
is_retryable_status, BasicWorkerBuilder, CircuitBreakerConfig, ConnectionMode, RetryExecutor,
Worker, WorkerRegistry, WorkerType,
};
use crate::metrics::RouterMetrics;
use crate::policies::{LoadBalancingPolicy, PolicyRegistry};
use crate::protocols::spec::{
ChatCompletionRequest, CompletionRequest, EmbeddingRequest, GenerateRequest, GenerationRequest,
RerankRequest, RerankResponse, RerankResult, ResponsesRequest,
};
use crate::routers::header_utils;
use crate::routers::{RouterTrait, WorkerManagement};
use axum::body::to_bytes;
use axum::{
body::Body,
extract::Request,
http::{
header::CONTENT_LENGTH, header::CONTENT_TYPE, HeaderMap, HeaderValue, Method, StatusCode,
},
response::{IntoResponse, Response},
Json,
};
use futures_util::StreamExt;
use reqwest::Client;
use std::collections::HashMap;
use std::sync::Arc;
use std::time::{Duration, Instant};
use tokio_stream::wrappers::UnboundedReceiverStream;
use tracing::{debug, error, info, warn};
/// Regular router that uses injected load balancing policies
#[derive(Debug)]
pub struct Router {
worker_registry: Arc<WorkerRegistry>,
policy_registry: Arc<PolicyRegistry>,
client: Client,
worker_startup_timeout_secs: u64,
worker_startup_check_interval_secs: u64,
dp_aware: bool,
#[allow(dead_code)]
api_key: Option<String>,
retry_config: RetryConfig,
circuit_breaker_config: CircuitBreakerConfig,
_worker_loads: Arc<tokio::sync::watch::Receiver<HashMap<String, isize>>>,
_load_monitor_handle: Option<Arc<tokio::task::JoinHandle<()>>>,
}
impl Router {
/// Create a new router with injected policy and client
pub async fn new(ctx: &Arc<crate::server::AppContext>) -> Result<Self, String> {
let workers = ctx.worker_registry.get_workers_filtered(
None, // any model
Some(WorkerType::Regular),
Some(ConnectionMode::Http),
false, // include all workers
);
// Update active workers gauge
RouterMetrics::set_active_workers(workers.len());
// Get worker URLs for monitoring
let worker_urls: Vec<String> = workers.iter().map(|w| w.url().to_string()).collect();
// Convert config CircuitBreakerConfig to core CircuitBreakerConfig
let circuit_breaker_config = ctx.router_config.effective_circuit_breaker_config();
let core_cb_config = CircuitBreakerConfig {
failure_threshold: circuit_breaker_config.failure_threshold,
success_threshold: circuit_breaker_config.success_threshold,
timeout_duration: Duration::from_secs(circuit_breaker_config.timeout_duration_secs),
window_duration: Duration::from_secs(circuit_breaker_config.window_duration_secs),
};
// Cache-aware policies are initialized in WorkerInitializer
// Setup load monitoring for PowerOfTwo policy
let (tx, rx) = tokio::sync::watch::channel(HashMap::new());
let worker_loads = Arc::new(rx);
// Get default policy to check if we need load monitoring
let default_policy = ctx.policy_registry.get_default_policy();
// Check if default policy is power_of_two for load monitoring
let load_monitor_handle = if default_policy.name() == "power_of_two" {
let monitor_urls = worker_urls.clone();
let monitor_api_keys = monitor_urls
.iter()
.map(|url| {
ctx.worker_registry
.get_by_url(url)
.and_then(|w| w.api_key().clone())
})
.collect::<Vec<Option<String>>>();
let monitor_interval = ctx.router_config.worker_startup_check_interval_secs;
let policy_clone = default_policy.clone();
let client_clone = ctx.client.clone();
Some(Arc::new(tokio::spawn(async move {
Self::monitor_worker_loads(
monitor_urls,
monitor_api_keys,
tx,
monitor_interval,
policy_clone,
client_clone,
)
.await;
})))
} else {
None
};
Ok(Router {
worker_registry: ctx.worker_registry.clone(),
policy_registry: ctx.policy_registry.clone(),
client: ctx.client.clone(),
worker_startup_timeout_secs: ctx.router_config.worker_startup_timeout_secs,
worker_startup_check_interval_secs: ctx
.router_config
.worker_startup_check_interval_secs,
dp_aware: ctx.router_config.dp_aware,
api_key: ctx.router_config.api_key.clone(),
retry_config: ctx.router_config.effective_retry_config(),
circuit_breaker_config: core_cb_config,
_worker_loads: worker_loads,
_load_monitor_handle: load_monitor_handle,
})
}
/// Get the current list of worker URLs
pub fn get_worker_urls(&self) -> Vec<String> {
self.worker_registry.get_all_urls()
}
/// Get worker URLs for a specific model
pub fn get_worker_urls_for_model(&self, model_id: Option<&str>) -> Vec<String> {
let workers = self.worker_registry.get_workers_filtered(
model_id,
Some(WorkerType::Regular),
Some(ConnectionMode::Http),
false, // get all workers
);
workers.iter().map(|w| w.url().to_string()).collect()
}
pub async fn wait_for_healthy_workers(
worker_urls: &[String],
worker_startup_timeout_secs: u64,
worker_startup_check_interval_secs: u64,
) -> Result<(), String> {
if worker_urls.is_empty() {
return Err(
"Timeout waiting for workers to become healthy: no workers provided".to_string(),
);
}
// Perform health check asynchronously
Self::wait_for_healthy_workers_async(
worker_urls,
worker_startup_timeout_secs,
worker_startup_check_interval_secs,
)
.await
}
async fn wait_for_healthy_workers_async(
worker_urls: &[String],
worker_startup_timeout_secs: u64,
worker_startup_check_interval_secs: u64,
) -> Result<(), String> {
info!(
"Waiting for {} workers to become healthy (timeout: {}s)",
worker_urls.len(),
worker_startup_timeout_secs
);
let start_time = std::time::Instant::now();
let client = reqwest::Client::builder()
.timeout(Duration::from_secs(2))
.build()
.map_err(|e| format!("Failed to create HTTP client: {}", e))?;
loop {
if start_time.elapsed() > Duration::from_secs(worker_startup_timeout_secs) {
error!(
"Timeout {}s waiting for workers {:?} to become healthy. Please set --router-worker-startup-timeout-secs (sglang_router.launch_server) or --worker-startup-timeout-secs (sglang_worker.router) to a larger value",
worker_startup_timeout_secs, worker_urls
);
return Err(format!(
"Timeout {}s waiting for workers {:?} to become healthy. Please set --router-worker-startup-timeout-secs (sglang_router.launch_server) or --worker-startup-timeout-secs (sglang_worker.router) to a larger value",
worker_startup_timeout_secs, worker_urls
));
}
// Perform all health checks concurrently
let mut health_checks = Vec::new();
for url in worker_urls {
let client_clone = client.clone();
let url_clone = url.clone();
let check_health = tokio::spawn(async move {
let health_url = format!("{}/health", url_clone);
match client_clone.get(&health_url).send().await {
Ok(res) => {
if res.status().is_success() {
None
} else {
Some((url_clone, format!("status: {}", res.status())))
}
}
Err(_) => Some((url_clone, "not ready".to_string())),
}
});
health_checks.push(check_health);
}
// Wait for all health checks to complete
let results = futures::future::join_all(health_checks).await;
let mut all_healthy = true;
let mut unhealthy_workers = Vec::new();
for result in results {
match result {
Ok(None) => {
// Worker is healthy
}
Ok(Some((url, reason))) => {
all_healthy = false;
unhealthy_workers.push((url, reason));
}
Err(e) => {
all_healthy = false;
unhealthy_workers
.push(("unknown".to_string(), format!("task error: {}", e)));
}
}
}
if all_healthy {
info!("All {} workers are healthy", worker_urls.len());
return Ok(());
} else {
debug!(
"Waiting for {} workers to become healthy ({} unhealthy: {:?})",
worker_urls.len(),
unhealthy_workers.len(),
unhealthy_workers
);
tokio::time::sleep(Duration::from_secs(worker_startup_check_interval_secs)).await;
}
}
}
fn get_worker_dp_size(worker_url: &str, api_key: &Option<String>) -> Result<usize, String> {
let sync_client = reqwest::blocking::Client::new();
let mut req_builder = sync_client.get(format!("{}/get_server_info", worker_url));
if let Some(key) = api_key {
req_builder = req_builder.bearer_auth(key);
}
match req_builder.send() {
Ok(res) => {
if res.status().is_success() {
let server_info = res
.text()
.map_err(|e| format!("failed to read text from response: {}", e))?;
let server_info: serde_json::Value = serde_json::from_str(&server_info)
.map_err(|e| format!("failed to decode JSON: {}", e))?;
let dp_size = server_info
.get("dp_size")
.and_then(|v| v.as_u64())
.ok_or_else(|| String::from("dp_size not found or not an u64"))?;
Ok(if dp_size > usize::MAX as u64 {
return Err(format!("dp_size is too large: {}", dp_size));
} else {
dp_size as usize
})
} else {
Err(format!("unexpected status code: {}", res.status()))
}
}
Err(e) => Err(format!("error response: {}", e)),
}
}
// Given a list of workers, return a list of workers with dp_rank as suffix
fn get_dp_aware_workers(
worker_urls: &[String],
api_key: &Option<String>,
) -> Result<Vec<String>, String> {
let mut dp_aware_workers: Vec<String> = Vec::new();
for url in worker_urls {
match Self::get_worker_dp_size(url, api_key) {
Ok(dp_size) => {
for i in 0..dp_size {
dp_aware_workers.push(format!("{}@{}", url, i));
}
}
Err(e) => return Err(format!("Failed to get DP size for {}: {}", url, e)),
}
}
Ok(dp_aware_workers)
}
fn select_first_worker(&self) -> Result<String, String> {
let workers = self.worker_registry.get_all();
if workers.is_empty() {
Err("No workers are available".to_string())
} else {
Ok(workers[0].url().to_string())
}
}
pub async fn send_health_check(&self, worker_url: &str) -> Response {
let health_url = if self.dp_aware {
// Need to extract the URL from "http://host:port@dp_rank"
match Self::extract_dp_rank(worker_url) {
Ok((worker_url_prefix, _dp_rank)) => worker_url_prefix,
Err(e) => {
error!("Failed to extract dp_rank for health check: {}", e);
return (
StatusCode::INTERNAL_SERVER_ERROR,
format!("Failed to extract dp_rank: {}", e),
)
.into_response();
}
}
} else {
worker_url
};
let request_builder = self.client.get(format!("{}/health", health_url));
let response = match request_builder.send().await {
Ok(res) => {
let status = StatusCode::from_u16(res.status().as_u16())
.unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);
match res.bytes().await {
Ok(body) => (status, body).into_response(),
Err(e) => {
error!(
worker_url = %health_url,
error = %e,
"Failed to read health response body"
);
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("Failed to read response body: {}", e),
)
.into_response()
}
}
}
Err(e) => {
error!(
worker_url = %health_url,
error = %e,
"Failed to send health request to worker"
);
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("Failed to send request to worker {}: {}", health_url, e),
)
.into_response()
}
};
// Don't record metrics for health checks
response
}
// Helper method to proxy GET requests to the first available worker
async fn proxy_get_request(&self, req: Request<Body>, endpoint: &str) -> Response {
let headers = header_utils::copy_request_headers(&req);
match self.select_first_worker() {
Ok(worker_url) => {
let mut request_builder = self.client.get(format!("{}/{}", worker_url, endpoint));
for (name, value) in headers {
let name_lc = name.to_lowercase();
if name_lc != "content-type" && name_lc != "content-length" {
request_builder = request_builder.header(name, value);
}
}
match request_builder.send().await {
Ok(res) => {
let status = StatusCode::from_u16(res.status().as_u16())
.unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);
// Preserve headers from backend
let response_headers =
header_utils::preserve_response_headers(res.headers());
match res.bytes().await {
Ok(body) => {
let mut response = Response::new(axum::body::Body::from(body));
*response.status_mut() = status;
*response.headers_mut() = response_headers;
response
}
Err(e) => (
StatusCode::INTERNAL_SERVER_ERROR,
format!("Failed to read response: {}", e),
)
.into_response(),
}
}
Err(e) => (
StatusCode::INTERNAL_SERVER_ERROR,
format!("Request failed: {}", e),
)
.into_response(),
}
}
Err(e) => (StatusCode::SERVICE_UNAVAILABLE, e).into_response(),
}
}
/// Select worker for a specific model considering circuit breaker state
fn select_worker_for_model(
&self,
model_id: Option<&str>,
text: Option<&str>,
) -> Option<Arc<dyn Worker>> {
// Get workers for the specified model O(1), filtered by connection mode
let workers = self.worker_registry.get_workers_filtered(
model_id,
Some(WorkerType::Regular),
Some(ConnectionMode::Http),
false, // get all workers, we'll filter by is_available() next
);
let available: Vec<Arc<dyn Worker>> = workers
.iter()
.filter(|w| w.is_available())
.cloned()
.collect();
if available.is_empty() {
return None;
}
// Get the appropriate policy for this model
let policy = match model_id {
Some(model) => self.policy_registry.get_policy_or_default(model),
None => self.policy_registry.get_default_policy(),
};
let idx = policy.select_worker(&available, text)?;
Some(available[idx].clone())
}
pub async fn route_typed_request<T: GenerationRequest + serde::Serialize + Clone>(
&self,
headers: Option<&HeaderMap>,
typed_req: &T,
route: &str,
model_id: Option<&str>,
) -> Response {
let start = Instant::now();
let is_stream = typed_req.is_stream();
let text = typed_req.extract_text_for_routing();
let response = RetryExecutor::execute_response_with_retry(
&self.retry_config,
// operation per attempt
|_: u32| async {
let worker = match self.select_worker_for_model(model_id, Some(&text)) {
Some(w) => w,
None => {
RouterMetrics::record_request_error(route, "no_available_workers");
return (
StatusCode::SERVICE_UNAVAILABLE,
"No available workers (all circuits open or unhealthy)",
)
.into_response();
}
};
// Optional load tracking for cache-aware policy
// Get the policy for this model to check if it's cache-aware
let policy = match model_id {
Some(model) => self.policy_registry.get_policy_or_default(model),
None => self.policy_registry.get_default_policy(),
};
let load_incremented = if policy.name() == "cache_aware" {
worker.increment_load();
RouterMetrics::set_running_requests(worker.url(), worker.load());
true
} else {
false
};
// Keep a clone for potential cleanup on retry
let worker_for_cleanup = if load_incremented {
Some(worker.clone())
} else {
None
};
let response = self
.send_typed_request(
headers,
typed_req,
route,
worker.url(),
is_stream,
load_incremented,
)
.await;
worker.record_outcome(response.status().is_success());
// For retryable failures, we need to decrement load since send_typed_request
// won't have done it (it only decrements on success or non-retryable failures)
if is_retryable_status(response.status()) && load_incremented {
if let Some(cleanup_worker) = worker_for_cleanup {
cleanup_worker.decrement_load();
RouterMetrics::set_running_requests(
cleanup_worker.url(),
cleanup_worker.load(),
);
}
}
response
},
// should_retry predicate
|res, _attempt| is_retryable_status(res.status()),
// on_backoff hook
|delay, attempt| {
RouterMetrics::record_retry(route);
RouterMetrics::record_retry_backoff_duration(delay, attempt);
},
// on_exhausted hook
|| RouterMetrics::record_retries_exhausted(route),
)
.await;
if response.status().is_success() {
let duration = start.elapsed();
RouterMetrics::record_request(route);
RouterMetrics::record_generate_duration(duration);
} else if !is_retryable_status(response.status()) {
RouterMetrics::record_request_error(route, "non_retryable_error");
}
response
}
// Helper: return base worker URL (strips DP suffix when enabled)
fn worker_base_url(&self, worker_url: &str) -> String {
if self.dp_aware {
if let Ok((prefix, _)) = Self::extract_dp_rank(worker_url) {
return prefix.to_string();
}
}
worker_url.to_string()
}
// Generic simple routing for GET/POST without JSON body
async fn route_simple_request(
&self,
headers: Option<&HeaderMap>,
endpoint: &str,
method: Method,
) -> Response {
// TODO: currently the sglang worker is using in-memory state management, so this implementation has to fan out to all workers.
// Eventually, we need to have router to manage the chat history with a proper database, will update this implementation accordingly.
let worker_urls = self.get_worker_urls();
if worker_urls.is_empty() {
return (StatusCode::SERVICE_UNAVAILABLE, "No available workers").into_response();
}
let mut last_response: Option<Response> = None;
for worker_url in worker_urls {
let base = self.worker_base_url(&worker_url);
let url = format!("{}/{}", base, endpoint);
let mut request_builder = match method {
Method::GET => self.client.get(url),
Method::POST => self.client.post(url),
_ => {
return (
StatusCode::METHOD_NOT_ALLOWED,
"Unsupported method for simple routing",
)
.into_response()
}
};
if let Some(hdrs) = headers {
for (name, value) in hdrs {
let name_lc = name.as_str().to_lowercase();
if name_lc != "content-type" && name_lc != "content-length" {
request_builder = request_builder.header(name, value);
}
}
}
match request_builder.send().await {
Ok(res) => {
let status = StatusCode::from_u16(res.status().as_u16())
.unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);
let response_headers = header_utils::preserve_response_headers(res.headers());
match res.bytes().await {
Ok(body) => {
let mut response = Response::new(axum::body::Body::from(body));
*response.status_mut() = status;
*response.headers_mut() = response_headers;
if status.is_success() {
return response;
}
last_response = Some(response);
}
Err(e) => {
last_response = Some(
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("Failed to read response: {}", e),
)
.into_response(),
);
}
}
}
Err(e) => {
last_response = Some(
(
StatusCode::INTERNAL_SERVER_ERROR,
format!("Request failed: {}", e),
)
.into_response(),
);
}
}
}
last_response
.unwrap_or_else(|| (StatusCode::BAD_GATEWAY, "No worker response").into_response())
}
// Route a GET request with provided headers to a specific endpoint
async fn route_get_request(&self, headers: Option<&HeaderMap>, endpoint: &str) -> Response {
self.route_simple_request(headers, endpoint, Method::GET)
.await
}
// Route a POST request with empty body to a specific endpoint
async fn route_post_empty_request(
&self,
headers: Option<&HeaderMap>,
endpoint: &str,
) -> Response {
self.route_simple_request(headers, endpoint, Method::POST)
.await
}
// TODO (rui): Better accommodate to the Worker abstraction
fn extract_dp_rank(worker_url: &str) -> Result<(&str, usize), String> {
let parts: Vec<&str> = worker_url.split('@').collect();
if parts.len() != 2 {
return Err(format!("invalid worker_url format: {}", worker_url));
}
// Parse the second part (dp_rank) into an integer
match parts[1].parse::<usize>() {
Ok(dp_rank) => Ok((parts[0], dp_rank)),
Err(_) => Err(format!(
"failed to parse dp_rank from worker_url: {}",
worker_url
)),
}
}
// Send typed request directly without conversion
async fn send_typed_request<T: serde::Serialize>(
&self,
headers: Option<&HeaderMap>,
typed_req: &T,
route: &str,
worker_url: &str,
is_stream: bool,
load_incremented: bool, // Whether load was incremented for this request
) -> Response {
let mut request_builder = if self.dp_aware {
let (worker_url_prefix, dp_rank) = match Self::extract_dp_rank(worker_url) {
Ok(tup) => tup,
Err(e) => {
error!("Failed to extract dp_rank: {}", e);
return (
StatusCode::INTERNAL_SERVER_ERROR,
format!("Failed to extract dp_rank: {}", e),
)
.into_response();
}
};
// Parse the request body
let mut json_val = match serde_json::to_value(typed_req) {
Ok(j) => j,
Err(e) => {
return (
StatusCode::BAD_REQUEST,
format!("Convert into serde_json::Value failed: {}", e),
)
.into_response();
}
};
// Insert the data_parallel_rank field
if let Some(map) = json_val.as_object_mut() {
map.insert(
String::from("data_parallel_rank"),
serde_json::json!(dp_rank),
);
debug!(
"Modified request body: {}",
serde_json::to_string(&json_val).unwrap_or(String::from("ERR"))
);
} else {
return (
StatusCode::BAD_REQUEST,
"Failed to insert the data_parallel_rank field into the request body",
)
.into_response();
}
self.client
.post(format!("{}{}", worker_url_prefix, route))
.json(&json_val)
} else {
self.client
.post(format!("{}{}", worker_url, route))
.json(typed_req) // Use json() directly with typed request
};
// Copy all headers from original request if provided
if let Some(headers) = headers {
for (name, value) in headers {
// Skip Content-Type and Content-Length as .json() sets them
if *name != CONTENT_TYPE && *name != CONTENT_LENGTH {
request_builder = request_builder.header(name, value);
}
}
}
let res = match request_builder.send().await {
Ok(res) => res,
Err(e) => {
error!(
"Failed to send typed request worker_url={} route={} error={}",
worker_url, route, e
);
// Decrement load on error if it was incremented
if load_incremented {
if let Some(worker) = self.worker_registry.get_by_url(worker_url) {
worker.decrement_load();
RouterMetrics::set_running_requests(worker_url, worker.load());
}
}
return (
StatusCode::INTERNAL_SERVER_ERROR,
format!("Request failed: {}", e),
)
.into_response();
}
};
let status = StatusCode::from_u16(res.status().as_u16())
.unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);
if !is_stream {
// For non-streaming requests, preserve headers
let response_headers = header_utils::preserve_response_headers(res.headers());
let response = match res.bytes().await {
Ok(body) => {
let mut response = Response::new(axum::body::Body::from(body));
*response.status_mut() = status;
*response.headers_mut() = response_headers;
response
}
Err(e) => {
// IMPORTANT: Decrement load on error before returning
if load_incremented {
if let Some(worker) = self.worker_registry.get_by_url(worker_url) {
worker.decrement_load();
RouterMetrics::set_running_requests(worker_url, worker.load());
}
}
let error_msg = format!("Failed to get response body: {}", e);
(StatusCode::INTERNAL_SERVER_ERROR, error_msg).into_response()
}
};
// Decrement load counter for non-streaming requests if it was incremented
if load_incremented {
if let Some(worker) = self.worker_registry.get_by_url(worker_url) {
worker.decrement_load();
RouterMetrics::set_running_requests(worker_url, worker.load());
}
}
response
} else if load_incremented {
// For streaming with load tracking, we need to manually decrement when done
let registry = Arc::clone(&self.worker_registry);
let worker_url = worker_url.to_string();
// Preserve headers for streaming response
let mut response_headers = header_utils::preserve_response_headers(res.headers());
// Ensure we set the correct content-type for SSE
response_headers.insert(CONTENT_TYPE, HeaderValue::from_static("text/event-stream"));
let stream = res.bytes_stream();
let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
// Spawn task to forward stream and detect completion
tokio::spawn(async move {
let mut stream = stream;
let mut decremented = false;
while let Some(chunk) = stream.next().await {
match chunk {
Ok(bytes) => {
// Check for stream end marker
if bytes
.as_ref()
.windows(12)
.any(|window| window == b"data: [DONE]")
{
if let Some(worker) = registry.get_by_url(&worker_url) {
worker.decrement_load();
RouterMetrics::set_running_requests(&worker_url, worker.load());
decremented = true;
}
}
if tx.send(Ok(bytes)).is_err() {
break;
}
}
Err(e) => {
let _ = tx.send(Err(format!("Stream error: {}", e)));
break;
}
}
}
if !decremented {
if let Some(worker) = registry.get_by_url(&worker_url) {
worker.decrement_load();
RouterMetrics::set_running_requests(&worker_url, worker.load());
}
}
});
let stream = UnboundedReceiverStream::new(rx);
let body = Body::from_stream(stream);
let mut response = Response::new(body);
*response.status_mut() = status;
*response.headers_mut() = response_headers;
response
} else {
// For requests without load tracking, just stream
// Preserve headers for streaming response
let mut response_headers = header_utils::preserve_response_headers(res.headers());
// Ensure we set the correct content-type for SSE
response_headers.insert(CONTENT_TYPE, HeaderValue::from_static("text/event-stream"));
let stream = res.bytes_stream();
let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
// Spawn task to forward stream
tokio::spawn(async move {
let mut stream = stream;
while let Some(chunk) = stream.next().await {
match chunk {
Ok(bytes) => {
if tx.send(Ok(bytes)).is_err() {
break;
}
}
Err(e) => {
let _ = tx.send(Err(format!("Stream error: {}", e)));
break;
}
}
}
});
let stream = UnboundedReceiverStream::new(rx);
let body = Body::from_stream(stream);
let mut response = Response::new(body);
*response.status_mut() = status;
*response.headers_mut() = response_headers;
response
}
}
pub async fn add_worker(
&self,
worker_url: &str,
api_key: &Option<String>,
) -> Result<String, String> {
let start_time = std::time::Instant::now();
let client = reqwest::Client::builder()
.timeout(Duration::from_secs(self.worker_startup_timeout_secs))
.build()
.map_err(|e| format!("Failed to create HTTP client: {}", e))?;
loop {
if start_time.elapsed() > Duration::from_secs(self.worker_startup_timeout_secs) {
error!(
"Timeout {}s waiting for worker {} to become healthy. Please set --router-worker-startup-timeout-secs (sglang_router.launch_server) or --worker-startup-timeout-secs (sglang_worker.router) to a larger value",
self.worker_startup_timeout_secs, worker_url
);
return Err(format!(
"Timeout {}s waiting for worker {} to become healthy. Please set --router-worker-startup-timeout-secs (sglang_router.launch_server) or --worker-startup-timeout-secs (sglang_worker.router) to a larger value",
self.worker_startup_timeout_secs, worker_url
));
}
match client.get(format!("{}/health", worker_url)).send().await {
Ok(res) => {
if res.status().is_success() {
if self.dp_aware {
// Need to contact the worker to extract the dp_size,
// and add them as multiple workers
let url_vec = vec![String::from(worker_url)];
let dp_url_vec = Self::get_dp_aware_workers(&url_vec, api_key)
.map_err(|e| format!("Failed to get dp-aware workers: {}", e))?;
let mut worker_added: bool = false;
for dp_url in &dp_url_vec {
if self.worker_registry.get_by_url(dp_url).is_some() {
warn!("Worker {} already exists", dp_url);
continue;
}
info!("Added worker: {}", dp_url);
// TODO: In IGW mode, fetch model_id from worker's /get_model_info endpoint
let new_worker_builder =
BasicWorkerBuilder::new(dp_url.to_string())
.worker_type(WorkerType::Regular)
.circuit_breaker_config(
self.circuit_breaker_config.clone(),
);
let new_worker = if let Some(api_key) = api_key {
new_worker_builder.api_key(api_key).build()
} else {
new_worker_builder.build()
};
let worker_arc = Arc::new(new_worker);
self.worker_registry.register(worker_arc.clone());
// Notify PolicyRegistry about the new worker
let model_id = worker_arc.model_id();
self.policy_registry.on_worker_added(model_id, None);
// Initialize cache-aware policy if applicable
let model_workers = self.worker_registry.get_workers_filtered(
Some(model_id),
Some(WorkerType::Regular),
Some(ConnectionMode::Http),
false,
);
self.policy_registry
.init_cache_aware_policy(model_id, &model_workers);
worker_added = true;
}
if !worker_added {
return Err(format!("No worker added for {}", worker_url));
}
} else {
if self.worker_registry.get_by_url(worker_url).is_some() {
return Err(format!("Worker {} already exists", worker_url));
}
info!("Added worker: {}", worker_url);
// TODO: In IGW mode, fetch model_id from worker's /get_model_info endpoint
let new_worker_builder =
BasicWorkerBuilder::new(worker_url.to_string())
.worker_type(WorkerType::Regular)
.circuit_breaker_config(self.circuit_breaker_config.clone());
let new_worker = if let Some(api_key) = api_key {
new_worker_builder.api_key(api_key).build()
} else {
new_worker_builder.build()
};
let worker_arc = Arc::new(new_worker);
self.worker_registry.register(worker_arc.clone());
// Notify PolicyRegistry about the new worker
let model_id = worker_arc.model_id();
self.policy_registry.on_worker_added(model_id, None);
// Initialize cache-aware policy if applicable
let model_workers = self.worker_registry.get_workers_filtered(
Some(model_id),
Some(WorkerType::Regular),
Some(ConnectionMode::Http),
false,
);
self.policy_registry
.init_cache_aware_policy(model_id, &model_workers);
}
RouterMetrics::set_active_workers(self.worker_registry.get_all().len());
return Ok(format!("Successfully added worker: {}", worker_url));
} else {
debug!(
"Worker {} health check pending - status: {}",
worker_url,
res.status()
);
// if the url does not have http or https prefix, warn users
if !worker_url.starts_with("http://") && !worker_url.starts_with("https://")
{
warn!("The worker url {} does not have http or https prefix. Please add the prefix to the url.", worker_url);
}
tokio::time::sleep(Duration::from_secs(
self.worker_startup_check_interval_secs,
))
.await;
continue;
}
}
Err(e) => {
debug!("Worker {} health check pending - error: {}", worker_url, e);
// if the url does not have http or https prefix, warn users
if !worker_url.starts_with("http://") && !worker_url.starts_with("https://") {
warn!("The worker url {} does not have http or https prefix. Please add the prefix to the url.", worker_url);
}
tokio::time::sleep(Duration::from_secs(
self.worker_startup_check_interval_secs,
))
.await;
continue;
}
}
}
}
pub fn remove_worker(&self, worker_url: &str) {
if self.dp_aware {
// remove dp-aware workers in a prefix-matching fashion
// without contacting the remote worker
let mut removed_workers: Vec<String> = Vec::new();
let worker_url_prefix = format!("{}@", worker_url);
// Find and remove all workers with matching prefix
let all_workers = self.worker_registry.get_all();
for w in all_workers.iter() {
if w.url().starts_with(&worker_url_prefix) {
// Get model_id before removing
let model_id = w.model_id().to_string();
if self.worker_registry.remove_by_url(w.url()).is_some() {
info!("Removed worker: {}", w.url());
removed_workers.push(w.url().to_string());
// Notify PolicyRegistry about the removed worker
self.policy_registry.on_worker_removed(&model_id);
} else {
warn!("Worker {} not found, skipping removal", w.url());
}
}
}
RouterMetrics::set_active_workers(self.worker_registry.get_all().len());
for dp_url in removed_workers.iter() {
if let Some(worker) = self.worker_registry.get_by_url(dp_url) {
let model_id = worker.model_id();
self.policy_registry
.remove_worker_from_cache_aware(model_id, dp_url);
}
}
} else {
// Get the worker first to extract model_id
let model_id = if let Some(worker) = self.worker_registry.get_by_url(worker_url) {
worker.model_id().to_string()
} else {
warn!("Worker {} not found, skipping removal", worker_url);
return;
};
if self.worker_registry.remove_by_url(worker_url).is_some() {
info!("Removed worker: {}", worker_url);
// Notify PolicyRegistry about the removed worker
self.policy_registry.on_worker_removed(&model_id);
RouterMetrics::set_active_workers(self.worker_registry.get_all().len());
}
self.policy_registry
.remove_worker_from_cache_aware(&model_id, worker_url);
}
}
async fn get_worker_load(&self, worker_url: &str, api_key: &Option<String>) -> Option<isize> {
let worker_url = if self.dp_aware {
// Need to extract the URL from "http://host:port@dp_rank"
let (worker_url_prefix, _dp_rank) = match Self::extract_dp_rank(worker_url) {
Ok(tup) => tup,
Err(e) => {
error!("Failed to extract dp_rank: {}", e);
return None;
}
};
worker_url_prefix
} else {
worker_url
};
let mut req_builder = self.client.get(format!("{}/get_load", worker_url));
if let Some(key) = api_key {
req_builder = req_builder.bearer_auth(key);
}
match req_builder.send().await {
Ok(res) if res.status().is_success() => match res.bytes().await {
Ok(bytes) => match serde_json::from_slice::<serde_json::Value>(&bytes) {
Ok(data) => data
.get("load")
.and_then(|v| v.as_i64())
.map(|v| v as isize),
Err(e) => {
debug!("Failed to parse load response from {}: {}", worker_url, e);
None
}
},
Err(e) => {
debug!("Failed to read load response from {}: {}", worker_url, e);
None
}
},
Ok(res) => {
debug!(
"Worker {} returned non-success status: {}",
worker_url,
res.status()
);
None
}
Err(e) => {
debug!("Failed to get load from {}: {}", worker_url, e);
None
}
}
}
// Background task to monitor worker loads
async fn monitor_worker_loads(
worker_urls: Vec<String>,
worker_api_keys: Vec<Option<String>>,
tx: tokio::sync::watch::Sender<HashMap<String, isize>>,
interval_secs: u64,
policy: Arc<dyn LoadBalancingPolicy>,
client: Client,
) {
let mut interval = tokio::time::interval(Duration::from_secs(interval_secs));
loop {
interval.tick().await;
let mut loads = HashMap::new();
for (url, api_key) in worker_urls.iter().zip(worker_api_keys.iter()) {
if let Some(load) = Self::get_worker_load_static(&client, url, api_key).await {
loads.insert(url.clone(), load);
}
}
if !loads.is_empty() {
// Update policy with new loads
policy.update_loads(&loads);
// Send to watchers
if let Err(e) = tx.send(loads) {
error!("Failed to send load update: {}", e);
}
}
}
}
// Static version of get_worker_load for use in monitoring task
async fn get_worker_load_static(
client: &reqwest::Client,
worker_url: &str,
api_key: &Option<String>,
) -> Option<isize> {
let worker_url = if worker_url.contains("@") {
// Need to extract the URL from "http://host:port@dp_rank"
let (worker_url_prefix, _dp_rank) = match Self::extract_dp_rank(worker_url) {
Ok(tup) => tup,
Err(e) => {
debug!("Failed to extract dp_rank: {}", e);
return None;
}
};
worker_url_prefix
} else {
worker_url
};
let mut req_builder = client.get(format!("{}/get_load", worker_url));
if let Some(key) = api_key {
req_builder = req_builder.bearer_auth(key);
}
match req_builder.send().await {
Ok(res) if res.status().is_success() => match res.bytes().await {
Ok(bytes) => match serde_json::from_slice::<serde_json::Value>(&bytes) {
Ok(data) => data
.get("load")
.and_then(|v| v.as_i64())
.map(|v| v as isize),
Err(e) => {
debug!("Failed to parse load response from {}: {}", worker_url, e);
None
}
},
Err(e) => {
debug!("Failed to read load response from {}: {}", worker_url, e);
None
}
},
Ok(res) => {
debug!(
"Worker {} returned non-success status: {}",
worker_url,
res.status()
);
None
}
Err(e) => {
debug!("Failed to get load from {}: {}", worker_url, e);
None
}
}
}
async fn build_rerank_response(
req: &RerankRequest,
response: Response,
) -> anyhow::Result<Response> {
let (_, response_body) = response.into_parts();
let body_bytes = to_bytes(response_body, usize::MAX).await?;
let rerank_results = serde_json::from_slice::<Vec<RerankResult>>(&body_bytes)?;
let mut rerank_response =
RerankResponse::new(rerank_results, req.model.clone(), req.rid.clone());
rerank_response.sort_by_score();
if let Some(top_k) = req.top_k {
rerank_response.apply_top_k(top_k);
}
if !req.return_documents {
rerank_response.drop_documents();
}
Ok(Json(rerank_response).into_response())
}
}
use async_trait::async_trait;
#[async_trait]
impl WorkerManagement for Router {
async fn add_worker(
&self,
worker_url: &str,
api_key: &Option<String>,
) -> Result<String, String> {
Router::add_worker(self, worker_url, api_key).await
}
fn remove_worker(&self, worker_url: &str) {
Router::remove_worker(self, worker_url)
}
fn get_worker_urls(&self) -> Vec<String> {
Router::get_worker_urls(self)
}
}
#[async_trait]
impl RouterTrait for Router {
fn as_any(&self) -> &dyn std::any::Any {
self
}
async fn health(&self, _req: Request<Body>) -> Response {
let workers = self.worker_registry.get_all();
let unhealthy_servers: Vec<_> = workers
.iter()
.filter(|w| !w.is_healthy())
.map(|w| w.url().to_string())
.collect();
if unhealthy_servers.is_empty() {
(StatusCode::OK, "All servers healthy").into_response()
} else {
(
StatusCode::SERVICE_UNAVAILABLE,
format!("Unhealthy servers: {:?}", unhealthy_servers),
)
.into_response()
}
}
async fn health_generate(&self, req: Request<Body>) -> Response {
self.proxy_get_request(req, "health_generate").await
}
async fn get_server_info(&self, req: Request<Body>) -> Response {
self.proxy_get_request(req, "get_server_info").await
}
async fn get_models(&self, req: Request<Body>) -> Response {
self.proxy_get_request(req, "v1/models").await
}
async fn get_model_info(&self, req: Request<Body>) -> Response {
self.proxy_get_request(req, "get_model_info").await
}
async fn route_generate(
&self,
headers: Option<&HeaderMap>,
body: &GenerateRequest,
model_id: Option<&str>,
) -> Response {
self.route_typed_request(headers, body, "/generate", model_id)
.await
}
async fn route_chat(
&self,
headers: Option<&HeaderMap>,
body: &ChatCompletionRequest,
model_id: Option<&str>,
) -> Response {
self.route_typed_request(headers, body, "/v1/chat/completions", model_id)
.await
}
async fn route_completion(
&self,
headers: Option<&HeaderMap>,
body: &CompletionRequest,
model_id: Option<&str>,
) -> Response {
self.route_typed_request(headers, body, "/v1/completions", model_id)
.await
}
async fn route_responses(
&self,
headers: Option<&HeaderMap>,
body: &ResponsesRequest,
model_id: Option<&str>,
) -> Response {
self.route_typed_request(headers, body, "/v1/responses", model_id)
.await
}
async fn get_response(&self, headers: Option<&HeaderMap>, response_id: &str) -> Response {
let endpoint = format!("v1/responses/{}", response_id);
self.route_get_request(headers, &endpoint).await
}
async fn cancel_response(&self, headers: Option<&HeaderMap>, response_id: &str) -> Response {
let endpoint = format!("v1/responses/{}/cancel", response_id);
self.route_post_empty_request(headers, &endpoint).await
}
async fn route_embeddings(
&self,
headers: Option<&HeaderMap>,
body: &EmbeddingRequest,
model_id: Option<&str>,
) -> Response {
// Record embeddings-specific metrics in addition to general request metrics
let start = Instant::now();
let res = self
.route_typed_request(headers, body, "/v1/embeddings", model_id)
.await;
// Embedding specific metrics
if res.status().is_success() {
RouterMetrics::record_embeddings_request();
RouterMetrics::record_embeddings_duration(start.elapsed());
} else {
let error_type = format!("http_{}", res.status().as_u16());
RouterMetrics::record_embeddings_error(&error_type);
}
res
}
async fn route_rerank(
&self,
headers: Option<&HeaderMap>,
body: &RerankRequest,
model_id: Option<&str>,
) -> Response {
if let Err(e) = body.validate() {
return (StatusCode::BAD_REQUEST, e).into_response();
}
let response = self
.route_typed_request(headers, body, "/v1/rerank", model_id)
.await;
if response.status().is_success() {
match Self::build_rerank_response(body, response).await {
Ok(rerank_response) => rerank_response,
Err(e) => {
error!("Failed to build rerank response: {}", e);
return (
StatusCode::INTERNAL_SERVER_ERROR,
"Failed to build rerank response".to_string(),
)
.into_response();
}
}
} else {
response
}
}
async fn flush_cache(&self) -> Response {
// Get all worker URLs
let worker_urls = self.get_worker_urls();
// Send requests to all workers concurrently without headers
let mut tasks = Vec::new();
for worker_url in &worker_urls {
let worker_url = if self.dp_aware {
// Need to extract the URL from "http://host:port@dp_rank"
let (worker_url_prefix, _dp_rank) = match Self::extract_dp_rank(worker_url) {
Ok(tup) => tup,
Err(e) => {
error!("Failed to extract dp_rank: {}", e);
return (
StatusCode::INTERNAL_SERVER_ERROR,
format!("Failed to extract dp_rank: {}", e),
)
.into_response();
}
};
worker_url_prefix
} else {
worker_url
};
let request_builder = self.client.post(format!("{}/flush_cache", worker_url));
tasks.push(request_builder.send());
}
// Wait for all responses
let results = futures_util::future::join_all(tasks).await;
// Check if all succeeded
let all_success = results.iter().all(|r| {
r.as_ref()
.map(|res| res.status().is_success())
.unwrap_or(false)
});
if all_success {
(StatusCode::OK, "Cache flushed on all servers").into_response()
} else {
(
StatusCode::INTERNAL_SERVER_ERROR,
"Cache flush failed on one or more servers",
)
.into_response()
}
}
async fn get_worker_loads(&self) -> Response {
let urls_with_key = self.worker_registry.get_all_urls_with_api_key();
let mut loads = Vec::new();
// Get loads from all workers
for (url, api_key) in &urls_with_key {
let load = self.get_worker_load(url, api_key).await.unwrap_or(-1);
loads.push(serde_json::json!({
"worker": url,
"load": load
}));
}
Json(serde_json::json!({
"workers": loads
}))
.into_response()
}
fn router_type(&self) -> &'static str {
"regular"
}
fn readiness(&self) -> Response {
// Regular router is ready if it has at least one healthy worker
let workers = self.worker_registry.get_all();
let healthy_count = workers.iter().filter(|w| w.is_healthy()).count();
let total_workers = workers.len();
if healthy_count > 0 {
Json(serde_json::json!({
"status": "ready",
"healthy_workers": healthy_count,
"total_workers": total_workers
}))
.into_response()
} else {
(
StatusCode::SERVICE_UNAVAILABLE,
Json(serde_json::json!({
"status": "not_ready",
"reason": "no healthy workers available",
"total_workers": total_workers
})),
)
.into_response()
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use std::collections::HashMap;
fn create_test_regular_router() -> Router {
// Create registries
let worker_registry = Arc::new(WorkerRegistry::new());
let policy_registry = Arc::new(PolicyRegistry::new(
crate::config::types::PolicyConfig::RoundRobin,
));
// Register test workers
let worker1 = BasicWorkerBuilder::new("http://worker1:8080")
.worker_type(WorkerType::Regular)
.api_key("test_api_key")
.build();
let worker2 = BasicWorkerBuilder::new("http://worker2:8080")
.worker_type(WorkerType::Regular)
.api_key("test_api_key")
.build();
worker_registry.register(Arc::new(worker1));
worker_registry.register(Arc::new(worker2));
let (_, rx) = tokio::sync::watch::channel(HashMap::new());
Router {
worker_registry,
policy_registry,
worker_startup_timeout_secs: 5,
worker_startup_check_interval_secs: 1,
dp_aware: false,
api_key: None,
client: Client::new(),
retry_config: RetryConfig::default(),
circuit_breaker_config: CircuitBreakerConfig::default(),
_worker_loads: Arc::new(rx),
_load_monitor_handle: None,
}
}
#[test]
fn test_router_get_worker_urls_regular() {
let router = create_test_regular_router();
let urls = router.get_worker_urls();
assert_eq!(urls.len(), 2);
assert!(urls.contains(&"http://worker1:8080".to_string()));
assert!(urls.contains(&"http://worker2:8080".to_string()));
}
#[test]
fn test_select_first_worker_regular() {
let router = create_test_regular_router();
let result = router.select_first_worker();
assert!(result.is_ok());
let url = result.unwrap();
// DashMap doesn't guarantee order, so just check we get one of the workers
assert!(url == "http://worker1:8080" || url == "http://worker2:8080");
}
#[tokio::test]
async fn test_wait_for_healthy_workers_empty_list() {
// Empty list will return error immediately
let result = Router::wait_for_healthy_workers(&[], 1, 1).await;
assert!(result.is_err());
assert!(result.unwrap_err().contains("no workers provided"));
}
#[tokio::test]
async fn test_wait_for_healthy_workers_invalid_urls() {
// This test will timeout quickly since the URLs are invalid
let result =
Router::wait_for_healthy_workers(&["http://nonexistent:8080".to_string()], 1, 1).await;
assert!(result.is_err());
assert!(result.unwrap_err().contains("Timeout"));
}
}