router.rs 47.5 KB
Newer Older
1
use crate::config::types::{CircuitBreakerConfig as ConfigCircuitBreakerConfig, RetryConfig};
2
use crate::core::{CircuitBreakerConfig, HealthChecker, RetryExecutor, Worker, WorkerFactory};
3
use crate::metrics::RouterMetrics;
4
use crate::openai_api_types::{ChatCompletionRequest, CompletionRequest, GenerateRequest};
5
use crate::policies::LoadBalancingPolicy;
6
7
8
9
use crate::routers::{RouterTrait, WorkerManagement};
use axum::{
    body::Body,
    extract::Request,
10
    http::{header::CONTENT_LENGTH, header::CONTENT_TYPE, HeaderMap, HeaderValue, StatusCode},
11
12
13
14
    response::{IntoResponse, Response},
    Json,
};
use futures_util::StreamExt;
15
use reqwest::Client;
16
17
18
19
use std::collections::HashMap;
use std::sync::{Arc, RwLock};
use std::thread;
use std::time::{Duration, Instant};
20
use tokio_stream::wrappers::UnboundedReceiverStream;
21
use tracing::{debug, error, info, warn};
22
pub fn copy_request_headers(req: &Request<Body>) -> Vec<(String, String)> {
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
    req.headers()
        .iter()
        .filter_map(|(name, value)| {
            value
                .to_str()
                .ok()
                .map(|v| (name.to_string(), v.to_string()))
        })
        .collect()
}

/// Regular router that uses injected load balancing policies
#[derive(Debug)]
pub struct Router {
    workers: Arc<RwLock<Vec<Box<dyn Worker>>>>,
    policy: Arc<dyn LoadBalancingPolicy>,
39
    client: Client,
40
41
    timeout_secs: u64,
    interval_secs: u64,
42
43
    dp_aware: bool,
    api_key: Option<String>,
44
    retry_config: RetryConfig,
45
    circuit_breaker_config: CircuitBreakerConfig,
46
47
48
49
50
51
    _worker_loads: Arc<tokio::sync::watch::Receiver<HashMap<String, isize>>>,
    _load_monitor_handle: Option<Arc<tokio::task::JoinHandle<()>>>,
    _health_checker: Option<HealthChecker>,
}

impl Router {
52
    /// Create a new router with injected policy and client
53
54
55
    pub fn new(
        worker_urls: Vec<String>,
        policy: Arc<dyn LoadBalancingPolicy>,
56
        client: Client,
57
58
        timeout_secs: u64,
        interval_secs: u64,
59
60
        dp_aware: bool,
        api_key: Option<String>,
61
        retry_config: RetryConfig,
62
        circuit_breaker_config: ConfigCircuitBreakerConfig,
63
64
    ) -> Result<Self, String> {
        // Update active workers gauge
65
        RouterMetrics::set_active_workers(worker_urls.len());
66
67
68
69
70
71

        // Wait for workers to be healthy (skip if empty - for service discovery mode)
        if !worker_urls.is_empty() {
            Self::wait_for_healthy_workers(&worker_urls, timeout_secs, interval_secs)?;
        }

72
73
74
75
76
77
78
79
        let worker_urls = if dp_aware {
            // worker address now in the format of "http://host:port@dp_rank"
            Self::get_dp_aware_workers(&worker_urls, &api_key)
                .map_err(|e| format!("Failed to get dp-aware workers: {}", e))?
        } else {
            worker_urls
        };

80
81
82
83
84
85
86
87
88
89
90
91
        // Convert config CircuitBreakerConfig to core CircuitBreakerConfig
        let core_cb_config = CircuitBreakerConfig {
            failure_threshold: circuit_breaker_config.failure_threshold,
            success_threshold: circuit_breaker_config.success_threshold,
            timeout_duration: std::time::Duration::from_secs(
                circuit_breaker_config.timeout_duration_secs,
            ),
            window_duration: std::time::Duration::from_secs(
                circuit_breaker_config.window_duration_secs,
            ),
        };

92
93
94
        // Create Worker trait objects from URLs
        let workers: Vec<Box<dyn Worker>> = worker_urls
            .iter()
95
96
97
            .map(|url| {
                WorkerFactory::create_regular_with_config(url.clone(), core_cb_config.clone())
            })
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
            .collect();

        // Initialize policy with workers if needed (e.g., for cache-aware)
        if let Some(cache_aware) = policy
            .as_any()
            .downcast_ref::<crate::policies::CacheAwarePolicy>()
        {
            cache_aware.init_workers(&workers);
        }

        let workers = Arc::new(RwLock::new(workers));
        let health_checker = crate::core::start_health_checker(Arc::clone(&workers), interval_secs);

        // Setup load monitoring for PowerOfTwo policy
        let (tx, rx) = tokio::sync::watch::channel(HashMap::new());
        let worker_loads = Arc::new(rx);

        let load_monitor_handle = if policy.name() == "power_of_two" {
            let monitor_urls = worker_urls.clone();
            let monitor_interval = interval_secs;
            let policy_clone = Arc::clone(&policy);
119
            let client_clone = client.clone();
120
121

            Some(Arc::new(tokio::spawn(async move {
122
123
124
125
126
127
128
129
                Self::monitor_worker_loads(
                    monitor_urls,
                    tx,
                    monitor_interval,
                    policy_clone,
                    client_clone,
                )
                .await;
130
131
132
133
134
135
136
137
            })))
        } else {
            None
        };

        Ok(Router {
            workers,
            policy,
138
            client,
139
140
            timeout_secs,
            interval_secs,
141
142
            dp_aware,
            api_key,
143
            retry_config,
144
            circuit_breaker_config: core_cb_config,
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
            _worker_loads: worker_loads,
            _load_monitor_handle: load_monitor_handle,
            _health_checker: Some(health_checker),
        })
    }

    /// Get the current list of worker URLs
    pub fn get_worker_urls(&self) -> Vec<String> {
        self.workers
            .read()
            .unwrap()
            .iter()
            .map(|w| w.url().to_string())
            .collect()
    }

    pub fn wait_for_healthy_workers(
        worker_urls: &[String],
        timeout_secs: u64,
        interval_secs: u64,
    ) -> Result<(), String> {
166
167
168
169
170
171
        if worker_urls.is_empty() {
            return Err(
                "Timeout waiting for workers to become healthy: no workers provided".to_string(),
            );
        }

172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
        let start_time = std::time::Instant::now();
        let sync_client = reqwest::blocking::Client::builder()
            .timeout(Duration::from_secs(timeout_secs))
            .build()
            .map_err(|e| format!("Failed to create HTTP client: {}", e))?;

        loop {
            if start_time.elapsed() > Duration::from_secs(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",
                    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",
                    timeout_secs, worker_urls
                ));
            }

            let mut all_healthy = true;
            let mut unhealthy_workers = Vec::new();

            for url in worker_urls {
                match sync_client.get(&format!("{}/health", url)).send() {
                    Ok(res) => {
                        if !res.status().is_success() {
                            all_healthy = false;
198
                            unhealthy_workers.push((url, format!("status: {}", res.status())));
199
200
201
202
                        }
                    }
                    Err(_) => {
                        all_healthy = false;
203
                        unhealthy_workers.push((url, "not ready".to_string()));
204
205
206
207
208
                    }
                }
            }

            if all_healthy {
209
                info!("All {} workers are healthy", worker_urls.len());
210
211
                return Ok(());
            } else {
212
213
214
215
216
                debug!(
                    "Waiting for {} workers to become healthy ({} unhealthy)",
                    worker_urls.len(),
                    unhealthy_workers.len()
                );
217
218
219
220
221
                thread::sleep(Duration::from_secs(interval_secs));
            }
        }
    }

222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
    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)
    }

278
279
280
281
282
283
284
285
286
    fn select_first_worker(&self) -> Result<String, String> {
        let workers_guard = self.workers.read().unwrap();
        if workers_guard.is_empty() {
            Err("No workers are available".to_string())
        } else {
            Ok(workers_guard[0].url().to_string())
        }
    }

287
    pub async fn send_health_check(&self, worker_url: &str) -> Response {
288
        let health_url = if self.dp_aware {
289
            // Need to extract the URL from "http://host:port@dp_rank"
290
291
            match Self::extract_dp_rank(worker_url) {
                Ok((worker_url_prefix, _dp_rank)) => worker_url_prefix,
292
                Err(e) => {
293
294
295
296
297
298
                    error!("Failed to extract dp_rank for health check: {}", e);
                    return (
                        StatusCode::INTERNAL_SERVER_ERROR,
                        format!("Failed to extract dp_rank: {}", e),
                    )
                        .into_response();
299
                }
300
            }
301
302
303
304
        } else {
            worker_url
        };

305
        let request_builder = self.client.get(format!("{}/health", health_url));
306
307
308

        let response = match request_builder.send().await {
            Ok(res) => {
309
310
                let status = StatusCode::from_u16(res.status().as_u16())
                    .unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);
311
312

                match res.bytes().await {
313
                    Ok(body) => (status, body).into_response(),
314
315
                    Err(e) => {
                        error!(
316
                            worker_url = %health_url,
317
                            error = %e,
318
                            "Failed to read health response body"
319
                        );
320
321
322
323
324
                        (
                            StatusCode::INTERNAL_SERVER_ERROR,
                            format!("Failed to read response body: {}", e),
                        )
                            .into_response()
325
                    }
326
327
                }
            }
328
329
            Err(e) => {
                error!(
330
                    worker_url = %health_url,
331
                    error = %e,
332
                    "Failed to send health request to worker"
333
                );
334
335
336
337
338
                (
                    StatusCode::INTERNAL_SERVER_ERROR,
                    format!("Failed to send request to worker {}: {}", health_url, e),
                )
                    .into_response()
339
            }
340
341
        };

342
        // Don't record metrics for health checks
343
344
345
        response
    }

346
    // Helper method to proxy GET requests to the first available worker
347
    async fn proxy_get_request(&self, req: Request<Body>, endpoint: &str) -> Response {
348
349
350
351
        let headers = copy_request_headers(&req);

        match self.select_first_worker() {
            Ok(worker_url) => {
352
                let mut request_builder = self.client.get(format!("{}/{}", worker_url, endpoint));
353
                for (name, value) in headers {
354
355
                    let name_lc = name.to_lowercase();
                    if name_lc != "content-type" && name_lc != "content-length" {
356
357
358
                        request_builder = request_builder.header(name, value);
                    }
                }
359

360
361
362
363
364
365
366
367
368
369
370
                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) => (
                                StatusCode::INTERNAL_SERVER_ERROR,
                                format!("Failed to read response: {}", e),
                            )
                                .into_response(),
371
372
                        }
                    }
373
374
375
376
377
                    Err(e) => (
                        StatusCode::INTERNAL_SERVER_ERROR,
                        format!("Request failed: {}", e),
                    )
                        .into_response(),
378
379
                }
            }
380
            Err(e) => (StatusCode::SERVICE_UNAVAILABLE, e).into_response(),
381
382
383
384
        }
    }

    // New method to route typed requests directly
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
    /// Select worker considering circuit breaker state
    fn select_worker_with_circuit_breaker(&self, text: Option<&str>) -> Option<Box<dyn Worker>> {
        let workers = self.workers.read().ok()?;
        let available: Vec<Box<dyn Worker>> = workers
            .iter()
            .filter(|w| w.is_available())
            .map(|w| w.clone_worker())
            .collect();
        if available.is_empty() {
            return None;
        }
        let idx = self.policy.select_worker(&available, text)?;
        Some(available[idx].clone_worker())
    }

    fn is_retryable_status(status: StatusCode) -> bool {
        matches!(
            status,
            StatusCode::REQUEST_TIMEOUT
                | StatusCode::TOO_MANY_REQUESTS
                | StatusCode::INTERNAL_SERVER_ERROR
                | StatusCode::BAD_GATEWAY
                | StatusCode::SERVICE_UNAVAILABLE
                | StatusCode::GATEWAY_TIMEOUT
        )
    }

412
413
414
415
    pub async fn route_typed_request<
        T: crate::openai_api_types::GenerationRequest + serde::Serialize + Clone,
    >(
        &self,
416
        headers: Option<&HeaderMap>,
417
418
        typed_req: &T,
        route: &str,
419
    ) -> Response {
420
        let start = Instant::now();
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
        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_with_circuit_breaker(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();
                    }
                };
439

440
                // Optional load tracking for cache-aware policy
441
                let load_incremented = if self.policy.name() == "cache_aware" {
442
443
444
                    worker.increment_load();
                    RouterMetrics::set_running_requests(worker.url(), worker.load());
                    true
445
446
447
448
449
450
                } else {
                    false
                };

                let response = self
                    .send_typed_request(
451
                        headers,
452
453
                        typed_req,
                        route,
454
                        worker.url(),
455
456
457
458
459
                        is_stream,
                        load_incremented,
                    )
                    .await;

460
461
462
463
464
465
466
467
468
469
470
471
                worker.record_outcome(response.status().is_success());
                response
            },
            // should_retry predicate
            |res, _attempt| Self::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),
472
        )
473
474
475
476
477
478
479
480
        .await;

        if response.status().is_success() {
            let duration = start.elapsed();
            RouterMetrics::record_request(route);
            RouterMetrics::record_generate_duration(duration);
        } else if !Self::is_retryable_status(response.status()) {
            RouterMetrics::record_request_error(route, "non_retryable_error");
481
        }
482
483

        response
484
485
    }

486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
    // 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
            )),
        }
    }

503
504
505
    // Send typed request directly without conversion
    async fn send_typed_request<T: serde::Serialize>(
        &self,
506
        headers: Option<&HeaderMap>,
507
508
509
510
511
        typed_req: &T,
        route: &str,
        worker_url: &str,
        is_stream: bool,
        load_incremented: bool, // Whether load was incremented for this request
512
    ) -> Response {
513
514
515
516
517
        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);
518
519
520
521
522
                    return (
                        StatusCode::INTERNAL_SERVER_ERROR,
                        format!("Failed to extract dp_rank: {}", e),
                    )
                        .into_response();
523
524
525
526
527
528
529
                }
            };

            // Parse the request body
            let mut json_val = match serde_json::to_value(typed_req) {
                Ok(j) => j,
                Err(e) => {
530
531
532
533
534
                    return (
                        StatusCode::BAD_REQUEST,
                        format!("Convert into serde_json::Value failed: {}", e),
                    )
                        .into_response();
535
536
537
538
539
540
541
542
543
544
545
546
547
548
                }
            };

            // 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 {
549
550
551
552
553
                return (
                    StatusCode::BAD_REQUEST,
                    "Failed to insert the data_parallel_rank field into the request body",
                )
                    .into_response();
554
555
            }

556
            self.client
557
558
559
                .post(format!("{}{}", worker_url_prefix, route))
                .json(&json_val)
        } else {
560
            self.client
561
562
563
                .post(format!("{}{}", worker_url, route))
                .json(typed_req) // Use json() directly with typed request
        };
564

565
566
567
568
        // 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
569
                if *name != CONTENT_TYPE && *name != CONTENT_LENGTH {
570
571
                    request_builder = request_builder.header(name, value);
                }
572
573
574
575
576
577
            }
        }

        let res = match request_builder.send().await {
            Ok(res) => res,
            Err(e) => {
578
579
580
581
                error!(
                    "Failed to send typed request worker_url={} route={} error={}",
                    worker_url, route, e
                );
582
583
584
585
586
587

                // Decrement load on error if it was incremented
                if load_incremented {
                    if let Ok(workers_guard) = self.workers.read() {
                        if let Some(worker) = workers_guard.iter().find(|w| w.url() == worker_url) {
                            worker.decrement_load();
588
                            RouterMetrics::set_running_requests(&worker_url, worker.load());
589
590
591
592
                        }
                    }
                }

593
594
595
596
597
                return (
                    StatusCode::INTERNAL_SERVER_ERROR,
                    format!("Request failed: {}", e),
                )
                    .into_response();
598
599
600
            }
        };

601
602
        let status = StatusCode::from_u16(res.status().as_u16())
            .unwrap_or(StatusCode::INTERNAL_SERVER_ERROR);
603
604
605
606

        if !is_stream {
            // For non-streaming requests, get response first
            let response = match res.bytes().await {
607
                Ok(body) => (status, body).into_response(),
608
609
                Err(e) => {
                    let error_msg = format!("Failed to get response body: {}", e);
610
                    (StatusCode::INTERNAL_SERVER_ERROR, error_msg).into_response()
611
612
613
614
615
616
617
618
                }
            };

            // Decrement load counter for non-streaming requests if it was incremented
            if load_incremented && !is_stream {
                if let Ok(workers_guard) = self.workers.read() {
                    if let Some(worker) = workers_guard.iter().find(|w| w.url() == worker_url) {
                        worker.decrement_load();
619
                        RouterMetrics::set_running_requests(&worker_url, worker.load());
620
621
622
623
624
625
626
627
628
629
                    }
                }
            }

            response
        } else if load_incremented {
            // For streaming with load tracking, we need to manually decrement when done
            let workers = Arc::clone(&self.workers);
            let worker_url = worker_url.to_string();

630
631
632
633
634
635
            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;
636
                let mut decremented = false;
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
                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 Ok(workers_guard) = workers.read() {
                                    if let Some(worker) =
                                        workers_guard.iter().find(|w| w.url() == &worker_url)
                                    {
                                        worker.decrement_load();
                                        RouterMetrics::set_running_requests(
                                            &worker_url,
                                            worker.load(),
                                        );
655
                                        decremented = true;
656
657
658
                                    }
                                }
                            }
659
660
661
662
663
664
665
666
667
668
                            if tx.send(Ok(bytes)).is_err() {
                                break;
                            }
                        }
                        Err(e) => {
                            let _ = tx.send(Err(format!("Stream error: {}", e)));
                            break;
                        }
                    }
                }
669
670
671
672
673
674
675
676
677
                if !decremented {
                    if let Ok(workers_guard) = workers.read() {
                        if let Some(worker) = workers_guard.iter().find(|w| w.url() == &worker_url)
                        {
                            worker.decrement_load();
                            RouterMetrics::set_running_requests(&worker_url, worker.load());
                        }
                    }
                }
678
679
680
681
682
683
684
685
686
687
688
            });

            let stream = UnboundedReceiverStream::new(rx);
            let body = Body::from_stream(stream);

            let mut response = Response::new(body);
            *response.status_mut() = status;
            response
                .headers_mut()
                .insert(CONTENT_TYPE, HeaderValue::from_static("text/event-stream"));
            response
689
690
        } else {
            // For requests without load tracking, just stream
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
            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()
                .insert(CONTENT_TYPE, HeaderValue::from_static("text/event-stream"));
            response
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
        }
    }

    pub async fn add_worker(&self, worker_url: &str) -> Result<String, String> {
        let start_time = std::time::Instant::now();
        let client = reqwest::Client::builder()
            .timeout(Duration::from_secs(self.timeout_secs))
            .build()
            .map_err(|e| format!("Failed to create HTTP client: {}", e))?;

        loop {
            if start_time.elapsed() > Duration::from_secs(self.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.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.timeout_secs, worker_url
                ));
            }

            match client.get(&format!("{}/health", worker_url)).send().await {
                Ok(res) => {
                    if res.status().is_success() {
                        let mut workers_guard = self.workers.write().unwrap();
747
748
749
750
751
752
753
754
755
756
757
758
759
                        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, &self.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 workers_guard.iter().any(|w| w.url() == dp_url) {
                                    warn!("Worker {} already exists", dp_url);
                                    continue;
                                }
                                info!("Added worker: {}", dp_url);
760
761
762
763
                                let new_worker = WorkerFactory::create_regular_with_config(
                                    dp_url.to_string(),
                                    self.circuit_breaker_config.clone(),
                                );
764
765
766
767
768
769
770
771
772
773
774
                                workers_guard.push(new_worker);
                                worker_added = true;
                            }
                            if !worker_added {
                                return Err(format!("No worker added for {}", worker_url));
                            }
                        } else {
                            if workers_guard.iter().any(|w| w.url() == worker_url) {
                                return Err(format!("Worker {} already exists", worker_url));
                            }
                            info!("Added worker: {}", worker_url);
775
776
777
778
                            let new_worker = WorkerFactory::create_regular_with_config(
                                worker_url.to_string(),
                                self.circuit_breaker_config.clone(),
                            );
779
                            workers_guard.push(new_worker);
780
                        }
781

782
                        RouterMetrics::set_active_workers(workers_guard.len());
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797

                        // If cache aware policy, initialize the worker in the tree
                        if let Some(cache_aware) =
                            self.policy
                                .as_any()
                                .downcast_ref::<crate::policies::CacheAwarePolicy>()
                        {
                            // Get updated workers after adding
                            drop(workers_guard);
                            let workers_guard = self.workers.read().unwrap();
                            cache_aware.init_workers(&workers_guard);
                        }

                        return Ok(format!("Successfully added worker: {}", worker_url));
                    } else {
798
799
                        debug!(
                            "Worker {} health check pending - status: {}",
800
801
802
803
804
805
806
807
808
809
810
811
812
813
                            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.interval_secs)).await;
                        continue;
                    }
                }
                Err(e) => {
814
                    debug!("Worker {} health check pending - error: {}", worker_url, e);
815
816
817
818
819
820
821
822
823
824
825
826
827
828

                    // 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.interval_secs)).await;
                    continue;
                }
            }
        }
    }

    pub fn remove_worker(&self, worker_url: &str) {
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
        if self.dp_aware {
            // remove dp-aware workers in a prefix-matching fashion
            // without contacting the remote worker
            let mut candidate_workers: Vec<String> = Vec::new();
            let mut removed_workers: Vec<String> = Vec::new();
            let worker_url_prefix = format!("{}@", worker_url);

            {
                // find the candidate workers to be removed
                let workers_guard = self.workers.read().unwrap();
                for w in workers_guard.iter() {
                    if w.url().starts_with(&worker_url_prefix) {
                        candidate_workers.push(w.url().to_string());
                    }
                }
            }

            {
                // do the removing on the worker_urls
                let mut workers_guard = self.workers.write().unwrap();
                for dp_url in candidate_workers.iter() {
                    if let Some(index) = workers_guard.iter().position(|w| w.url() == dp_url) {
                        workers_guard.remove(index);
                        info!("Removed worker: {}", dp_url);
                        removed_workers.push(dp_url.to_string());
                    } else {
                        warn!("Worker {} not found, skipping removal", dp_url);
                        continue;
                    }
                }
                RouterMetrics::set_active_workers(workers_guard.len());
            }

            // If cache aware policy, remove the workers from the tree
            if let Some(cache_aware) = self
                .policy
                .as_any()
                .downcast_ref::<crate::policies::CacheAwarePolicy>()
            {
                for dp_url in removed_workers.iter() {
                    cache_aware.remove_worker(dp_url);
                    info!("Removed worker from tree: {}", dp_url);
                }
            }
        } else {
            let mut workers_guard = self.workers.write().unwrap();
            if let Some(index) = workers_guard.iter().position(|w| w.url() == worker_url) {
                workers_guard.remove(index);
                info!("Removed worker: {}", worker_url);
                RouterMetrics::set_active_workers(workers_guard.len());
            } else {
                warn!("Worker {} not found, skipping removal", worker_url);
                return;
            }

            // If cache aware policy, remove the workers from the tree
            if let Some(cache_aware) = self
                .policy
                .as_any()
                .downcast_ref::<crate::policies::CacheAwarePolicy>()
            {
                cache_aware.remove_worker(worker_url);
                info!("Removed worker from tree: {}", worker_url);
            }
        }
    }

896
    async fn get_worker_load(&self, worker_url: &str) -> Option<isize> {
897
898
899
900
901
902
903
904
905
906
907
908
909
910
        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
        };

911
912
913
914
915
916
        match self
            .client
            .get(&format!("{}/get_load", worker_url))
            .send()
            .await
        {
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
            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>,
        tx: tokio::sync::watch::Sender<HashMap<String, isize>>,
        interval_secs: u64,
        policy: Arc<dyn LoadBalancingPolicy>,
954
        client: Client,
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
    ) {
        let mut interval = tokio::time::interval(Duration::from_secs(interval_secs));

        loop {
            interval.tick().await;

            let mut loads = HashMap::new();
            for url in &worker_urls {
                if let Some(load) = Self::get_worker_load_static(&client, url).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) -> Option<isize> {
982
983
984
985
986
987
988
989
990
991
992
993
994
995
        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
        };

996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
        match client.get(&format!("{}/get_load", worker_url)).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
            }
        }
    }
}

use async_trait::async_trait;

#[async_trait]
impl WorkerManagement for Router {
    async fn add_worker(&self, worker_url: &str) -> Result<String, String> {
        Router::add_worker(self, worker_url).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)
    }
}

1046
#[async_trait]
1047
1048
1049
1050
1051
impl RouterTrait for Router {
    fn as_any(&self) -> &dyn std::any::Any {
        self
    }

1052
    async fn health(&self, _req: Request<Body>) -> Response {
1053
1054
1055
1056
1057
1058
        let workers = self.workers.read().unwrap();
        let unhealthy_servers: Vec<_> = workers
            .iter()
            .filter(|w| !w.is_healthy())
            .map(|w| w.url().to_string())
            .collect();
1059

1060
1061
        if unhealthy_servers.is_empty() {
            (StatusCode::OK, "All servers healthy").into_response()
1062
        } else {
1063
1064
1065
1066
1067
            (
                StatusCode::SERVICE_UNAVAILABLE,
                format!("Unhealthy servers: {:?}", unhealthy_servers),
            )
                .into_response()
1068
1069
1070
        }
    }

1071
1072
    async fn health_generate(&self, req: Request<Body>) -> Response {
        self.proxy_get_request(req, "health_generate").await
1073
1074
    }

1075
1076
    async fn get_server_info(&self, req: Request<Body>) -> Response {
        self.proxy_get_request(req, "get_server_info").await
1077
1078
    }

1079
1080
    async fn get_models(&self, req: Request<Body>) -> Response {
        self.proxy_get_request(req, "v1/models").await
1081
1082
    }

1083
1084
    async fn get_model_info(&self, req: Request<Body>) -> Response {
        self.proxy_get_request(req, "get_model_info").await
1085
1086
1087
1088
    }

    async fn route_generate(
        &self,
1089
1090
1091
        headers: Option<&HeaderMap>,
        body: &GenerateRequest,
    ) -> Response {
1092
        self.route_typed_request(headers, body, "/generate").await
1093
1094
1095
1096
    }

    async fn route_chat(
        &self,
1097
1098
1099
        headers: Option<&HeaderMap>,
        body: &ChatCompletionRequest,
    ) -> Response {
1100
        self.route_typed_request(headers, body, "/v1/chat/completions")
1101
            .await
1102
1103
1104
1105
    }

    async fn route_completion(
        &self,
1106
1107
1108
        headers: Option<&HeaderMap>,
        body: &CompletionRequest,
    ) -> Response {
1109
        self.route_typed_request(headers, body, "/v1/completions")
1110
            .await
1111
1112
    }

1113
    async fn flush_cache(&self) -> Response {
1114
1115
1116
1117
1118
1119
        // 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 {
1120
1121
1122
1123
1124
1125
            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);
1126
1127
1128
1129
1130
                        return (
                            StatusCode::INTERNAL_SERVER_ERROR,
                            format!("Failed to extract dp_rank: {}", e),
                        )
                            .into_response();
1131
1132
1133
1134
1135
1136
                    }
                };
                worker_url_prefix
            } else {
                worker_url
            };
1137
            let request_builder = self.client.post(format!("{}/flush_cache", worker_url));
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
            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 {
1152
            (StatusCode::OK, "Cache flushed on all servers").into_response()
1153
        } else {
1154
1155
1156
1157
1158
            (
                StatusCode::INTERNAL_SERVER_ERROR,
                "Cache flush failed on one or more servers",
            )
                .into_response()
1159
1160
1161
        }
    }

1162
    async fn get_worker_loads(&self) -> Response {
1163
1164
1165
1166
1167
        let urls = self.get_worker_urls();
        let mut loads = Vec::new();

        // Get loads from all workers
        for url in &urls {
1168
            let load = self.get_worker_load(url).await.unwrap_or(-1);
1169
1170
1171
1172
1173
1174
            loads.push(serde_json::json!({
                "worker": url,
                "load": load
            }));
        }

1175
        Json(serde_json::json!({
1176
1177
            "workers": loads
        }))
1178
        .into_response()
1179
1180
1181
1182
1183
1184
    }

    fn router_type(&self) -> &'static str {
        "regular"
    }

1185
    fn readiness(&self) -> Response {
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
        // Regular router is ready if it has at least one healthy worker
        let healthy_count = self
            .workers
            .read()
            .unwrap()
            .iter()
            .filter(|w| w.is_healthy())
            .count();

        if healthy_count > 0 {
1196
            Json(serde_json::json!({
1197
1198
1199
1200
                "status": "ready",
                "healthy_workers": healthy_count,
                "total_workers": self.workers.read().unwrap().len()
            }))
1201
            .into_response()
1202
        } else {
1203
1204
1205
1206
1207
1208
1209
1210
1211
            (
                StatusCode::SERVICE_UNAVAILABLE,
                Json(serde_json::json!({
                    "status": "not_ready",
                    "reason": "no healthy workers available",
                    "total_workers": self.workers.read().unwrap().len()
                })),
            )
                .into_response()
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::policies::RandomPolicy;
    use std::collections::HashMap;

    fn create_test_regular_router() -> Router {
        let workers = vec![
            WorkerFactory::create_regular("http://worker1:8080".to_string()),
            WorkerFactory::create_regular("http://worker2:8080".to_string()),
        ];
        let (_, rx) = tokio::sync::watch::channel(HashMap::new());
        Router {
            workers: Arc::new(RwLock::new(workers)),
            policy: Arc::new(RandomPolicy::new()),
            timeout_secs: 5,
            interval_secs: 1,
1233
1234
            dp_aware: false,
            api_key: None,
1235
            client: Client::new(),
1236
            retry_config: RetryConfig::default(),
1237
            circuit_breaker_config: CircuitBreakerConfig::default(),
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
            _worker_loads: Arc::new(rx),
            _load_monitor_handle: None,
            _health_checker: 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());
        assert_eq!(result.unwrap(), "http://worker1:8080");
    }

    #[test]
    fn test_wait_for_healthy_workers_empty_list() {
1265
        // Empty list will timeout as there are no workers to check
1266
        let result = Router::wait_for_healthy_workers(&[], 1, 1);
1267
1268
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("Timeout"));
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
    }

    #[test]
    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);
        assert!(result.is_err());
        assert!(result.unwrap_err().contains("Timeout"));
    }
}