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milan-berri
0fb710400f
* fix(spend_counter): seed Redis counter via SET NX to prevent cross-pod double-seed Symptom ------- Customers on multi-pod deployments see team `spend` jump to ~2x (or N x the pod count) shortly after a Redis cache miss / TTL expiry, triggering spurious "Budget Crossed" alerts and blocked requests until the value is manually reset. Root cause ---------- `SpendCounterReseed.coalesced` warmed the primary spend counter by calling `redis.async_increment(key, value=db_spend, refresh_ttl=True)`, which lowers to Redis `INCRBYFLOAT`. That is additive, not idempotent. The per-counter `asyncio.Lock` only coalesces seeders inside one process. With N pods sharing one Redis, on a cold key (cold start, TTL expiry, manual delete) every pod independently passes its lock + Redis re-check, reads the same `db_spend`, and issues `INCRBYFLOAT db_spend`. Final value: N x db_spend. Fix --- Use `redis.async_set_cache(key, value=db_spend, nx=True)` for the seed. SET NX is atomic across pods: exactly one writer initializes the key; losers read the winner's value via `async_get_cache`. This is the same idiom already used by `coalesced_window` in the same file, so the two seed paths are now consistent. Per-request deltas continue to use `INCRBYFLOAT` (correct - additive behaviour is what we want for increments, not for initial seed). Verification ------------ Live two-process repro against the same Postgres + Redis (DB spend = 506): Unpatched: 4/4 runs -> Redis counter = ~1012 (~2 x db_spend) Patched: 12/12 runs -> Redis counter = ~506 Unit tests (`test_proxy_server.py`): - New `test_primary_spend_counter_redis_concurrent_seed_does_not_double_seed` patches `_get_lock` to return a fresh lock per caller (otherwise the per-process lock masks the race), races two `coalesced` calls, and asserts final = 506 with exactly one of two SET NX attempts winning. - 4 existing tests updated for the new seed contract (SET NX for the seed, INCRBYFLOAT only for the per-request delta). - Full `spend_counter or reseed or budget` slice: 22 passed. Co-authored-by: Cursor <cursoragent@cursor.com> * test(spend_counter): make SET NX mock atomic so loser branch is exercised Greptile flagged that `redis_set_cache` in test_primary_spend_counter_redis_concurrent_seed_does_not_double_seed placed `await asyncio.sleep(0)` AFTER the NX membership check. Both concurrent tasks observed an empty `redis_store`, passed the guard, and both returned True - so the loser branch (else: read back winner's value) was never exercised. Fix the mock to model real atomic Redis SET NX: - Yield BEFORE the membership check so two concurrent callers interleave the way real SET NX does (first to resume runs check + write atomically and wins; second resumes after the key exists and loses). - Track set_cache return values; assert sorted([loser, winner]) so we know exactly one task wins and one loses. - Track async_get_cache calls that happen AFTER at least one SET NX has completed; assert at least one such read - that is the loser-path fallback (`current_value = float(cached)` when seeded is False). Verified by temporarily reverting the mock to the old order: the test now fails with `expected exactly one SET NX winner and one loser, got [True, True]`, exactly the failure mode Greptile described. No production code change. Co-authored-by: Cursor <cursoragent@cursor.com> * test(spend_counter): mock async_set_cache to populate redis_store in concurrent read+write test `test_concurrent_read_and_write_paths_share_one_db_query` mocks `async_increment` to populate the in-memory `redis_store`, but did not mock `async_set_cache`. After the SET-NX seed change in `coalesced()`, the seed step writes via `async_set_cache(nx=True)` (default AsyncMock, no `redis_store` write), so the simulated Redis stays empty after the first reseed. The second `get_current_spend` then sees a clean Redis miss, re-enters the DB read path, and the test fails with `expected 1 DB query, got 2`. Fix: add a `redis_set_cache` side_effect that updates `redis_store` on `nx=True` (and rejects when the key already exists), matching the pattern used by the four sibling tests fixed in this branch's first commit. Pre-existing assertions are unchanged. Full `tests/test_litellm/proxy/test_proxy_server.py`: 158 passed. Co-authored-by: Cursor <cursoragent@cursor.com> --------- Co-authored-by: Cursor <cursoragent@cursor.com>
In total litellm runs 1000+ tests
[02/20/2025] Update:
To make it easier to contribute and map what behavior is tested,
we've started mapping the litellm directory in tests/test_litellm
This folder can only run mock tests.