litellm-rs 0.9.0

A high-performance AI Gateway written in Rust, providing OpenAI-compatible APIs with intelligent routing, load balancing, and enterprise features
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
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
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
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
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
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
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
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
use super::router_tests::create_test_deployment;
use crate::core::router::config::RouterConfig;
use crate::core::router::deployment::{Deployment, DeploymentConfig};
use crate::core::router::error::RouterError;
use crate::core::router::unified::Router;
#[cfg(feature = "gateway")]
use std::sync::Arc;
use std::sync::atomic::Ordering;

#[tokio::test]
async fn unavailable_backend_fails_closed_without_reservation() {
    let router = Router::new(RouterConfig::default()).with_unavailable_admission();
    let deployment = limited_deployment("closed-1", Some(1), None, None).await;
    router.add_deployment(deployment);
    let err = router
        .select_deployment_lease("gpt-4")
        .expect_err("unavailable admission must fail closed");
    assert!(matches!(err, RouterError::NoAvailableDeployment(_)));
    let deployment = router.get_deployment("closed-1").unwrap();
    assert_eq!(deployment.state.active_requests.load(Ordering::Relaxed), 0);
    assert_eq!(deployment.state.fail_requests.load(Ordering::Relaxed), 0);
    assert!(!deployment.is_in_cooldown());
}

#[cfg(feature = "gateway")]
mod redis {
    use super::*;
    use crate::config::models::storage::RedisConfig;
    use crate::core::router::selection::DeploymentLease;
    use crate::core::types::model::ProviderCapability;
    use crate::storage::redis::RedisPool;

    #[tokio::test(flavor = "current_thread")]
    async fn provider_failure_survives_cancellation_before_circuit_bridge_admission() {
        use crate::core::providers::ProviderError;
        use crate::core::router::RuntimeBinding;
        use std::time::Duration;

        const CHILD: &str = "LITELLM_FAILURE_BEFORE_CIRCUIT_CHILD";
        if std::env::var_os(CHILD).is_none() {
            // This test occupies every circuit I/O slot. Isolate the process
            // so unrelated tests never wait behind its deliberate pause.
            let output = tokio::task::spawn_blocking(|| {
                std::process::Command::new(std::env::current_exe().unwrap())
                    .args([
                        "--exact",
                        "core::router::tests::admission_tests::redis::provider_failure_survives_cancellation_before_circuit_bridge_admission",
                        "--nocapture",
                    ])
                    .env(CHILD, "1")
                    .output()
                    .unwrap()
            })
            .await
            .unwrap();
            let stdout = String::from_utf8_lossy(&output.stdout);
            assert!(
                output.status.success() && stdout.contains("1 passed; 0 failed"),
                "isolated failure accounting must pass once:\n{stdout}\n{}",
                String::from_utf8_lossy(&output.stderr)
            );
            return;
        }
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        for (mode, retries, completed_usage) in [
            ("unary", 0, None),
            ("unary", 1, None),
            ("stream", 0, None),
            ("stream", 1, None),
            ("once", 0, None),
            ("unary", 0, Some(None)),
            ("unary", 0, Some(Some(0_u64))),
            ("unary", 0, Some(Some(3_u64))),
        ] {
            for cancel in [false, true] {
                let id = unique("failure-before-circuit");
                let router = Arc::new(
                    Router::new(RouterConfig {
                        num_retries: retries,
                        max_fallbacks: 0,
                        allowed_fails: 1,
                        min_requests: 1,
                        ..Default::default()
                    })
                    .with_admission_redis(pool.clone())
                    .with_circuit_redis(pool.clone()),
                );
                seed(&router, &id, Some(1), Some(10), Some(100)).await;
                let deployment = router.get_deployment(&id).unwrap();
                let handle = RuntimeBinding::new(router.clone()).bind();
                let paused = Arc::new(parking_lot::Mutex::new(None));
                let paused_in_provider = paused.clone();
                let fail = move |_deployment: Arc<Deployment>| {
                    let paused = paused_in_provider.clone();
                    async move {
                        let permit = crate::core::router::circuit::pause_circuit_io().await;
                        *paused.lock() = Some(permit);
                        Err::<(), ProviderError>(ProviderError::timeout(
                            "openai",
                            "completed failure",
                        ))
                    }
                };
                let mut request = Box::pin(async {
                    match mode {
                        "unary" => {
                            handle
                                .execute_with_selected_deployment_capability_typed(
                                    "gpt-4",
                                    &ProviderCapability::ChatCompletion,
                                    20,
                                    move |deployment| {
                                        let result = fail(deployment);
                                        async move {
                                            result
                                                .await
                                                .map(|()| ((), None::<u64>))
                                                .map_err(|error| (error, completed_usage))
                                        }
                                    },
                                )
                                .await
                                .unwrap_err();
                        }
                        "stream" => {
                            handle
                                .execute_stream_with_selected_deployment_capability_typed(
                                    "gpt-4",
                                    &ProviderCapability::ChatCompletionStream,
                                    20,
                                    fail,
                                )
                                .await
                                .unwrap_err();
                        }
                        "once" => {
                            router
                                .execute_once_with_selected_deployment("gpt-4", move |deployment| {
                                    let result = fail(deployment);
                                    async move { result.await.map(|()| ((), 0_u64)) }
                                })
                                .await
                                .unwrap_err();
                        }
                        _ => unreachable!(),
                    }
                });
                tokio::select! {
                    () = request.as_mut() => panic!("shared failure publication must remain paused"),
                    () = async {
                        tokio::time::timeout(Duration::from_secs(5), async {
                            while paused.lock().is_none() {
                                tokio::task::yield_now().await;
                            }
                        }).await.expect("provider must finish before shared publication waits");
                    } => {}
                }
                assert_eq!(deployment.state.total_requests.load(Ordering::Relaxed), 1);
                assert_eq!(deployment.state.fail_requests.load(Ordering::Relaxed), 1);
                assert_eq!(
                    deployment.state.rpm_current.load(Ordering::Relaxed),
                    u64::from(completed_usage.is_some())
                );
                assert_eq!(
                    deployment.state.tpm_current.load(Ordering::Relaxed),
                    completed_usage.flatten().unwrap_or(0)
                );
                assert!(deployment.is_in_cooldown());
                if cancel {
                    drop(request);
                    drop(paused.lock().take());
                } else {
                    drop(paused.lock().take());
                    request.await;
                }
                assert_eq!(deployment.state.active_requests.load(Ordering::Relaxed), 0);
                assert_eq!(deployment.state.total_requests.load(Ordering::Relaxed), 1);
                assert_eq!(deployment.state.fail_requests.load(Ordering::Relaxed), 1);
                assert_eq!(deployment.state.success_requests.load(Ordering::Relaxed), 0);
                assert_eq!(
                    deployment.state.rpm_current.load(Ordering::Relaxed),
                    u64::from(completed_usage.is_some())
                );
                assert_eq!(
                    deployment.state.tpm_current.load(Ordering::Relaxed),
                    completed_usage.flatten().unwrap_or(0)
                );
                let mut conn = pool.open_live_connection().await.unwrap();
                tokio::time::timeout(Duration::from_secs(5), async {
                    loop {
                        let counts: Vec<Option<i64>> = ::redis::cmd("HMGET")
                            .arg(RedisPool::admission_key(&id))
                            .arg(&["p", "r", "t"])
                            .query_async(&mut conn)
                            .await
                            .unwrap();
                        let expected_tokens = match completed_usage {
                            Some(Some(tokens)) => tokens as i64,
                            Some(None) => 20,
                            None => 0,
                        };
                        let expected =
                            vec![0, i64::from(completed_usage.is_some()), expected_tokens];
                        let fields: Vec<String> = ::redis::cmd("HKEYS")
                            .arg(RedisPool::admission_key(&id))
                            .query_async(&mut conn)
                            .await
                            .unwrap();
                        if counts
                            .iter()
                            .map(|value| value.unwrap_or(0))
                            .collect::<Vec<_>>()
                            == expected
                            && !fields.iter().any(|field| field.starts_with("l:"))
                        {
                            break;
                        }
                        tokio::task::yield_now().await;
                    }
                })
                .await
                .expect(
                    "ordinary failure refunds; completed response keeps known or estimated usage",
                );
                let shared: Vec<Option<i64>> = ::redis::cmd("HMGET")
                    .arg(RedisPool::circuit_key(&id))
                    .arg(&["tot", "fail"])
                    .query_async(&mut conn)
                    .await
                    .unwrap();
                let expected = i64::from(!cancel);
                assert_eq!(
                    shared
                        .iter()
                        .map(|value| value.unwrap_or(0))
                        .collect::<Vec<_>>(),
                    vec![expected, expected]
                );
                cleanup(&pool, &id).await;
                pool.delete(&RedisPool::circuit_key(&id)).await.unwrap();
            }
        }
    }

    #[tokio::test(flavor = "current_thread")]
    async fn legacy_id_selectors_release_shared_admission_before_returning() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        for capability in [false, true] {
            let id = unique("legacy-id");
            let a = router_with(pool.clone());
            let b = router_with(pool.clone());
            seed(&a, &id, Some(1), None, None).await;
            seed(&b, &id, Some(1), None, None).await;
            let selected = if capability {
                a.select_deployment_lease_for_capability(
                    "gpt-4",
                    &ProviderCapability::ChatCompletion,
                )
            } else {
                a.select_deployment_lease("gpt-4")
            }
            .map(DeploymentLease::into_deployment_id)
            .expect("legacy selector can reserve inside a current-thread runtime");
            assert_eq!(
                a.get_deployment(&id)
                    .unwrap()
                    .state
                    .active_requests
                    .load(Ordering::Relaxed),
                1
            );
            Router::release_selected_deployment(&a.get_deployment(&selected).unwrap());
            assert_eq!(
                a.get_deployment(&id)
                    .unwrap()
                    .state
                    .active_requests
                    .load(Ordering::Relaxed),
                0
            );
            let second = if capability {
                b.select_deployment_lease_for_capability(
                    "gpt-4",
                    &ProviderCapability::ChatCompletion,
                )
            } else {
                b.select_deployment_lease("gpt-4")
            }
            .map(DeploymentLease::into_deployment_id)
            .expect("legacy release must leave the shared parallel slot reusable immediately");
            Router::release_selected_deployment(&b.get_deployment(&second).unwrap());
            drop(
                a.select_deployment_lease("gpt-4")
                    .expect("owned admission remains reusable"),
            );
            cleanup(&pool, &id).await;
        }
    }

    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
    async fn two_routers_share_max_parallel_limit() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("parallel");
        let a = Arc::new(router_with(pool.clone()));
        let b = Arc::new(router_with(pool.clone()));
        seed(&a, &id, Some(1), None, None).await;
        seed(&b, &id, Some(1), None, None).await;

        let a_task = {
            let a = Arc::clone(&a);
            tokio::spawn(async move { a.select_deployment_lease("gpt-4") })
        };
        let b_task = {
            let b = Arc::clone(&b);
            tokio::spawn(async move { b.select_deployment_lease("gpt-4") })
        };
        let a_result = a_task.await.expect("join a");
        let b_result = b_task.await.expect("join b");
        let successes = [&a_result, &b_result]
            .iter()
            .filter(|result| result.is_ok())
            .count();
        assert_eq!(successes, 1, "replica count must not multiply max_parallel");

        for result in [&a_result, &b_result] {
            if let Err(err) = result {
                assert!(matches!(err, RouterError::NoAvailableDeployment(_)));
            }
        }
        let denied = a.get_deployment(&id).unwrap();
        assert_eq!(denied.state.fail_requests.load(Ordering::Relaxed), 0);
        assert!(!denied.is_in_cooldown());
        cleanup(&pool, &id).await;
    }

    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
    async fn two_routers_share_rpm_limit() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("rpm");
        let a = router_with(pool.clone());
        let b = router_with(pool.clone());
        seed(&a, &id, None, Some(1), None).await;
        seed(&b, &id, None, Some(1), None).await;

        let mut first = a
            .select_deployment_lease("gpt-4")
            .expect("first rpm reserve");
        assert!(
            b.select_deployment_lease("gpt-4").is_err(),
            "outstanding rpm must block the second replica"
        );
        first.commit_admission(0);
        drop(first);
        assert!(
            b.select_deployment_lease("gpt-4").is_err(),
            "settled rpm must still occupy the minute window"
        );
        cleanup(&pool, &id).await;
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn cancel_refunds_rpm_for_the_other_replica() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("rpm-cancel");
        let a = router_with(pool.clone());
        let b = router_with(pool.clone());
        seed(&a, &id, None, Some(1), None).await;
        seed(&b, &id, None, Some(1), None).await;

        drop(a.select_deployment_lease("gpt-4").expect("reserve"));
        b.select_deployment_lease("gpt-4")
            .expect("cancel must refund rpm so the other replica can admit");
        cleanup(&pool, &id).await;
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn tpm_estimate_is_shared_and_settled() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("tpm");
        let a = router_with(pool.clone());
        let b = router_with(pool.clone());
        seed(&a, &id, None, None, Some(10)).await;
        seed(&b, &id, None, None, Some(10)).await;

        let mut hold = a
            .select_deployment_lease_with_tokens("gpt-4", 10)
            .expect("first tpm reserve");
        assert!(b.select_deployment_lease_with_tokens("gpt-4", 1).is_err());
        hold.commit_admission(4);
        drop(hold);
        b.select_deployment_lease_with_tokens("gpt-4", 6)
            .expect("settled 4 of 10 should leave 6");
        cleanup(&pool, &id).await;
    }

    #[tokio::test(flavor = "current_thread")]
    async fn current_thread_runtime_can_admit_without_panic() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("current-thread");
        let router = router_with(pool.clone());
        seed(&router, &id, Some(1), None, None).await;
        let lease = router
            .select_deployment_lease("gpt-4")
            .expect("Actix workers use current_thread; admit must not panic");
        drop(lease);
        cleanup(&pool, &id).await;
    }

    #[tokio::test(flavor = "current_thread")]
    async fn synchronous_admission_works_inside_a_futures_executor() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("nested-executor");
        let a = router_with(pool.clone());
        let b = router_with(pool.clone());
        seed(&a, &id, Some(1), None, Some(10)).await;
        seed(&b, &id, Some(1), None, Some(10)).await;

        futures::executor::block_on(async {
            let mut lease = a
                .select_deployment_lease_with_tokens("gpt-4", 10)
                .expect("nested executor can reserve shared admission");
            assert!(b.select_deployment_lease_with_tokens("gpt-4", 1).is_err());
            lease.commit_admission(4);
            drop(lease);
            drop(
                b.select_deployment_lease_with_tokens("gpt-4", 6)
                    .expect("sync settlement records actual tokens"),
            );
            drop(
                a.select_deployment_lease_with_tokens("gpt-4", 6)
                    .expect("sync drop refunds the unused reservation"),
            );
        });
        cleanup(&pool, &id).await;
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn stream_disconnect_releases_parallel_slot() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("stream-drop");
        let a = router_with(pool.clone());
        let b = router_with(pool.clone());
        seed(&a, &id, Some(1), None, None).await;
        seed(&b, &id, Some(1), None, None).await;

        let lease = a.select_deployment_lease("gpt-4").expect("reserve");
        assert!(b.select_deployment_lease("gpt-4").is_err());
        drop(lease);
        b.select_deployment_lease("gpt-4")
            .expect("drop must release the shared parallel slot");
        cleanup(&pool, &id).await;
    }

    #[tokio::test(flavor = "current_thread")]
    async fn cancelled_success_settlement_retains_local_counts_for_all_execution_paths() {
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        for execution in ["once", "retry", "stream"] {
            let id = unique("cancel-success");
            let router = Arc::new(router_with(pool.clone()).with_circuit_redis(pool.clone()));
            seed(&router, &id, Some(1), Some(10), Some(100)).await;
            let (started, ready) = tokio::sync::oneshot::channel();
            let started = Arc::new(std::sync::Mutex::new(Some(started)));
            let worker = router.clone();
            let task = tokio::spawn(async move {
                if execution == "stream" {
                    let lease = worker.select_deployment_lease_async("gpt-4").await.unwrap();
                    let handle = crate::core::router::RuntimeBinding::new(worker.clone()).bind();
                    let mut completion = handle.stream_completion(lease, std::time::Instant::now());
                    completion.observe_usage(42);
                    let _slots = crate::core::router::admission::pause_admission_io().await;
                    let _ = started.lock().unwrap().take().unwrap().send(());
                    completion.finish_success().await;
                    return Ok(());
                }
                let operation = move |_| {
                    let started = started.clone();
                    async move {
                        // Reserve has finished. Hold every I/O permit in the
                        // result so the real settlement suspends until abort.
                        let slots = crate::core::router::admission::pause_admission_io().await;
                        let _ = started.lock().unwrap().take().unwrap().send(());
                        Ok((slots, 42))
                    }
                };
                if execution == "retry" {
                    worker
                        .execute_with_selected_deployment_retry("gpt-4", operation)
                        .await
                        .map(|_| ())
                } else {
                    worker
                        .execute_once_with_selected_deployment("gpt-4", operation)
                        .await
                        .map(|_| ())
                        .map_err(crate::core::router::execution::router_error_to_provider_error)
                        .map_err(|e| (e, 1))
                }
            });
            tokio::time::timeout(std::time::Duration::from_secs(10), ready)
                .await
                .unwrap()
                .unwrap();
            let mut conn = pool.open_live_connection().await.unwrap();
            tokio::time::timeout(std::time::Duration::from_secs(3), async {
                loop {
                    let successes: Option<i64> = ::redis::cmd("HGET")
                        .arg(RedisPool::circuit_key(&id))
                        .arg("r")
                        .query_async(&mut conn)
                        .await
                        .unwrap();
                    if successes == Some(1) {
                        break;
                    }
                    tokio::time::sleep(std::time::Duration::from_millis(10)).await;
                }
            })
            .await
            .expect("successful circuit outcome must precede blocked admission settlement");
            let before: (i64, i64) = ::redis::cmd("HMGET")
                .arg(RedisPool::circuit_key(&id))
                .arg(&["tot", "r"])
                .query_async(&mut conn)
                .await
                .unwrap();
            assert_eq!(before, (1, 1));
            let deployment = router.get_deployment(&id).unwrap();
            assert_eq!(deployment.state.success_requests.load(Ordering::Relaxed), 1);
            assert_eq!(deployment.state.total_requests.load(Ordering::Relaxed), 1);
            assert_eq!(deployment.state.rpm_current.load(Ordering::Relaxed), 1);
            assert_eq!(deployment.state.tpm_current.load(Ordering::Relaxed), 42);
            task.abort();
            assert!(task.await.unwrap_err().is_cancelled());
            assert_eq!(deployment.state.active_requests.load(Ordering::Relaxed), 0);
            assert_eq!(deployment.state.success_requests.load(Ordering::Relaxed), 1);
            // RAII must also retain actual shared usage after the waiter dies.
            let mut conn = pool.open_live_connection().await.unwrap();
            tokio::time::timeout(std::time::Duration::from_secs(3), async {
                loop {
                    let state: (i64, i64) = ::redis::cmd("HMGET")
                        .arg(RedisPool::admission_key(&id))
                        .arg(&["p", "t"])
                        .query_async(&mut conn)
                        .await
                        .unwrap();
                    if state == (0, 42) {
                        break;
                    }
                    tokio::time::sleep(std::time::Duration::from_millis(10)).await;
                }
            })
            .await
            .unwrap();
            let after: (i64, i64) = ::redis::cmd("HMGET")
                .arg(RedisPool::circuit_key(&id))
                .arg(&["tot", "r"])
                .query_async(&mut conn)
                .await
                .unwrap();
            assert_eq!(after, (1, 1), "abort must not record circuit success twice");
            cleanup(&pool, &id).await;
        }
    }

    #[tokio::test(flavor = "current_thread")]
    async fn resource_rotation_isolates_shared_admission_and_cached_circuit_state() {
        use crate::config::models::provider::ProviderConfig;
        use crate::core::router::runtime_state::GatewayRuntimeIdentity;

        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("resource-rotation");
        let router = router_with(pool.clone()).with_circuit_redis(pool.clone());
        let mut config = ProviderConfig {
            api_key: "retired-test-credential".into(),
            ..ProviderConfig::default()
        };
        let old_identity = GatewayRuntimeIdentity::for_provider(&config).for_model("gpt-4");
        let mut old = limited_deployment(&id, Some(1), Some(1), Some(10)).await;
        old.state.runtime_identity = Some(old_identity);
        router.add_deployment(old);
        let mut lease = router.select_deployment_lease_async("gpt-4").await.unwrap();
        let old_shared_id = lease.deployment().shared_state_id();
        router.record_failure_with_reason(&id, crate::core::router::CooldownReason::AuthError);
        assert!(router.select_deployment_lease_async("gpt-4").await.is_err());

        config.api_key = "rotated-test-credential".into();
        let new_identity = GatewayRuntimeIdentity::for_provider(&config).for_model("gpt-4");
        let mut replacement = limited_deployment(&id, Some(1), Some(1), Some(10)).await;
        replacement.state.runtime_identity = Some(new_identity.clone());
        let mut replacement_router = router_with(pool.clone());
        // A real gateway revision inherits state by construction identity.
        // Retain the backend cache too, so cached old cooldown cannot hide a
        // correct Redis namespace behind an ID-only local lookup.
        replacement_router.circuit = router.circuit.clone();
        replacement_router.add_deployment(replacement);
        replacement_router.inherit_runtime_state(&router);
        let mut replacement_lease = replacement_router
            .select_deployment_lease_async("gpt-4")
            .await
            .expect("rotated resource must not inherit the old lease or cached auth cooldown");
        let peer = router_with(pool.clone()).with_circuit_redis(pool.clone());
        let mut same_resource = limited_deployment(&id, Some(1), Some(1), Some(10)).await;
        same_resource.state.runtime_identity = Some(new_identity);
        peer.add_deployment(same_resource);
        assert!(
            peer.select_deployment_lease_async("gpt-4").await.is_err(),
            "replicas of the same replacement still share the parallel limit"
        );
        let new_shared_id = replacement_lease.deployment().shared_state_id();
        lease.commit_admission_async(7).await;
        replacement_lease.commit_admission_async(4).await;
        let mut conn = pool.open_live_connection().await.unwrap();
        for (shared_id, tokens) in [(&old_shared_id, 7), (&new_shared_id, 4)] {
            let state: (i64, i64) = ::redis::cmd("HMGET")
                .arg(RedisPool::admission_key(shared_id))
                .arg(&["p", "t"])
                .query_async(&mut conn)
                .await
                .unwrap();
            assert_eq!(
                state,
                (0, tokens),
                "each hold finishes in its original resource namespace"
            );
            cleanup(&pool, shared_id).await;
            pool.delete(&RedisPool::circuit_key(shared_id))
                .await
                .unwrap();
        }
        drop(replacement_lease);
        drop(lease);
    }

    #[tokio::test(flavor = "current_thread")]
    async fn cleanup_capacity_is_reserved_before_admission_and_known_usage_is_retained() {
        use crate::core::router::admission::{AdmissionBackend, AdmissionReserve};

        // Match the budget bridge's subprocess isolation: this test owns every
        // process-wide cleanup slot without rejecting unrelated parallel tests.
        const CHILD: &str = "LITELLM_ADMISSION_CLEANUP_TEST_CHILD";
        let module = module_path!().split_once("::").unwrap().1;
        let name = format!(
            "{module}::cleanup_capacity_is_reserved_before_admission_and_known_usage_is_retained"
        );
        if std::env::var(CHILD).as_deref() != Ok(name.as_str()) {
            let output = tokio::task::spawn_blocking(move || {
                std::process::Command::new(std::env::current_exe().unwrap())
                    .args(["--exact", &name, "--nocapture", "--test-threads=1"])
                    .env(CHILD, &name)
                    .output()
                    .unwrap()
            })
            .await
            .unwrap();
            let stdout = String::from_utf8_lossy(&output.stdout);
            assert!(
                output.status.success() && stdout.contains("1 passed; 0 failed"),
                "isolated cleanup regression must run once and pass:\n{stdout}\n{}",
                String::from_utf8_lossy(&output.stderr)
            );
            return;
        }
        let Some(pool) = live_redis_pool().await else {
            return;
        };
        let id = unique("cleanup-capacity");
        let deployment = limited_deployment(&id, Some(2_000), None, Some(100_000)).await;
        let backend = AdmissionBackend::redis(pool.clone());
        let mut conn = pool.open_live_connection().await.unwrap();
        let (seconds, micros): (u64, u64) =
            ::redis::cmd("TIME").query_async(&mut conn).await.unwrap();
        // The exact TPM assertion belongs to one Redis minute. Completed
        // usage expires at rollover, unlike outstanding reservations.
        let remaining_ms = 60_000 - (seconds % 60 * 1_000 + micros / 1_000);
        if remaining_ms < 15_000 {
            tokio::time::sleep(std::time::Duration::from_millis(remaining_ms + 1)).await;
        }
        let mut holds = Vec::new();
        for _ in 0..1_024 {
            match backend.reserve_async(&deployment, 1).await {
                AdmissionReserve::Granted(hold) => holds.push(hold),
                _ => panic!("cleanup capacity must accommodate 1024 owned holds"),
            }
        }
        assert!(
            matches!(
                backend.reserve_async(&deployment, 1).await,
                AdmissionReserve::Unavailable
            ),
            "saturated cleanup capacity must fail closed before accepting more liabilities"
        );
        for hold in &holds {
            hold.prepare_settlement(2);
        }
        drop(holds);
        tokio::time::timeout(std::time::Duration::from_secs(10), async {
            loop {
                let (parallel, tokens): (i64, i64) = ::redis::cmd("HMGET")
                    .arg(RedisPool::admission_key(&id))
                    .arg(&["p", "t"])
                    .query_async(&mut conn)
                    .await
                    .unwrap();
                if parallel == 0 {
                    assert_eq!(
                        tokens, 2_048,
                        "every queued completion must retain actual usage"
                    );
                    break;
                }
                tokio::time::sleep(std::time::Duration::from_millis(10)).await;
            }
        })
        .await
        .expect("all owned cleanup events must finish");
        let AdmissionReserve::Granted(hold) = backend.reserve_async(&deployment, 1).await else {
            panic!("terminal cleanup releases process admission capacity");
        };
        backend.cancel_async(&hold).await;
        drop(hold);
        cleanup(&pool, &id).await;
    }

    fn router_with(pool: Arc<RedisPool>) -> Router {
        Router::new(RouterConfig::default()).with_admission_redis(pool)
    }

    async fn seed(
        router: &Router,
        id: &str,
        max_parallel: Option<u32>,
        rpm: Option<u64>,
        tpm: Option<u64>,
    ) {
        router.add_deployment(limited_deployment(id, max_parallel, rpm, tpm).await);
    }

    fn unique(prefix: &str) -> String {
        format!("{prefix}-{}", uuid::Uuid::new_v4())
    }

    async fn cleanup(pool: &RedisPool, deployment_id: &str) {
        let _ = pool.delete(&RedisPool::admission_key(deployment_id)).await;
    }

    async fn live_redis_pool() -> Option<Arc<RedisPool>> {
        let redis_url =
            std::env::var("REDIS_URL").unwrap_or_else(|_| "redis://127.0.0.1:6379".into());
        let config = RedisConfig {
            url: redis_url.clone(),
            enabled: true,
            max_connections: 10,
            connection_timeout: 1,
            cluster: false,
            allow_degraded: false,
        };

        match RedisPool::new(&config).await {
            Ok(pool) => match pool.health_check().await {
                Ok(()) => Some(Arc::new(pool)),
                Err(err) => {
                    if std::env::var("CI").is_ok() {
                        panic!("Redis should pass health check in CI at {redis_url}: {err}");
                    }
                    eprintln!("Skipping distributed admission Redis integration test: {err}");
                    None
                }
            },
            Err(err) => {
                if std::env::var("CI").is_ok() {
                    panic!("Redis should be reachable in CI at {redis_url}: {err}");
                }
                eprintln!("Skipping distributed admission Redis integration test: {err}");
                None
            }
        }
    }
}

async fn limited_deployment(
    id: &str,
    max_parallel: Option<u32>,
    rpm: Option<u64>,
    tpm: Option<u64>,
) -> Deployment {
    create_test_deployment(id, "gpt-4")
        .await
        .with_config(DeploymentConfig {
            max_parallel_requests: max_parallel,
            rpm_limit: rpm,
            tpm_limit: tpm,
            ..Default::default()
        })
}