Cache-hit EAGLE/NextN draft was falling back to full materialization while the target path used page-aligned prefix materialize plus fresh current-suffix splice. That creates a target/draft KV source asymmetry exactly on the high-cache-hit path where decode accept length collapsed. The draft model still does not get next-layer async prefetch; only the same-layer current suffix compose contract is made role-agnostic. Constraint: EAGLE/NextN has no real next decoder layer, so draft async prefetch remains disabled. Rejected: Restore draft full-materialize fallback | recreates the observed target/draft cache-hit asymmetry and hides stale-current-suffix bugs. Confidence: medium Scope-risk: moderate Directive: Do not reintroduce draft cache-hit current-reuse fallback without proving the draft persistent pool has fully fresh suffix rows before attention. Tested: Local py_compile for cp_shared_kv_runtime.py and test_cp_shared_kv_runtime.py. Tested: Remote g0034 container py_compile for changed runtime/test files. Tested: Remote g0034 pytest test_cp_shared_kv_runtime.py: 73 passed, 5 warnings, 2 subtests passed. Tested: Remote g0034 related suite test_nsa_cp_utils.py test_cp_shared_kv_layout.py test_cp_shared_kv_runtime.py: 128 passed, 5 warnings, 2 subtests passed. Not-tested: ETE cache-hit accept-length validation after restarting prefill/decode with this synced code.
Unit Tests
Component-level tests that do not launch a server or load model weights. Tests can use CPU or GPU — the key criterion is no server process.
Quick Start
- Find the source file under
python/sglang/srt/. - Create the corresponding test here, mirroring the source tree:
srt/mem_cache/radix_cache.py → unit/mem_cache/test_radix_cache.py srt/sampling/sampling_params.py → unit/sampling/test_sampling_params.py - Register for CI at the top of the file (after imports, before test classes):
from sglang.test.ci.ci_register import register_cpu_ci register_cpu_ci(est_time=5, suite="stage-a-test-cpu") # or: register_cuda_ci(est_time=10, suite="stage-b-test-1-gpu-small") - Run locally:
pytest test/registered/unit/ -v # all unit tests pytest test/registered/unit/mem_cache/ -v # one module - Run with coverage:
# summary pytest test/registered/unit/ --cov --cov-config=.coveragerc -v # PR incremental check (require ≥60% on changed lines) pytest test/registered/unit/ --cov --cov-config=.coveragerc --cov-report=xml diff-cover coverage.xml --compare-branch=origin/main --fail-under=60
Example
"""Unit tests for <module> — no server, no model loading."""
from sglang.test.ci.ci_register import register_cpu_ci
register_cpu_ci(est_time=5, suite="stage-a-test-cpu")
import unittest
from sglang.srt.<module> import TargetClass
from sglang.test.test_utils import CustomTestCase
class TestTargetClass(CustomTestCase):
def test_basic_behavior(self):
obj = TargetClass(...)
self.assertEqual(obj.method(), expected)
if __name__ == "__main__":
unittest.main()
Rules
- No
popen_launch_server()orEngine(...). - No model weight loading.
- Use
CustomTestCase(fromsglang.test.test_utils, adds CI retry). - Use
unittest.mockfor dependencies that are expensive to construct.