[HiCache] Fix the compatibility between PP and HiCache (L2). (#27285)

Co-authored-by: ybyang <ybyang7@iflytek.com>
Co-authored-by: hzh0425 <hzh0425@apache.org>
Co-authored-by: shangmingc <csmthu@gmail.com>
Co-authored-by: 晟海 <huangtingwei.htw@antgroup.com>

test/registered/radix_cache/unified_radix_tree/test_unified_radix_cache_hicache_pp_kl.py

@@ -0,0 +1,107 @@
+import unittest
+from types import SimpleNamespace
+from urllib.parse import urlparse
+
+from sglang.srt.utils import kill_process_tree
+from sglang.test.ci.ci_register import register_cuda_ci
+from sglang.test.kits.unified_radix_cache_kit import UnifiedRadixTreeTestMixin
+from sglang.test.kl_multiturn_utils import get_input_ids
+from sglang.test.test_utils import (
+    DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
+    DEFAULT_URL_FOR_TEST,
+    CustomTestCase,
+    popen_launch_server,
+)
+
+register_cuda_ci(est_time=400, stage="base-c", runner_config="4-gpu-h100")
+
+QWEN3_30B_MODEL = "Qwen/Qwen3-30B-A3B-FP8"
+
+
+def _assert_pp_decode_cached_tokens(result, history_len, output_len, label):
+    expected = history_len + output_len
+    actual = result["meta_info"]["cached_tokens"]
+    lower = max(0, expected - 1)
+    assert (
+        lower <= actual <= expected
+    ), f"{label}: expected cached_tokens in [{lower}, {expected}], got {actual}"
+
+
+class TestUnifiedQwen3HiCachePP(UnifiedRadixTreeTestMixin, CustomTestCase):
+    """Qwen3-30B-A3B-FP8 + HiCache + PP + UnifiedRadixCache."""
+
+    hicache_io_backend = "direct"
+    hicache_mem_layout = "page_first_direct"
+    max_running_requests = 4
+    kl_threshold = 0.012
+    gsm8k_threshold = 0.7
+    num_gsm8k_questions = 50
+    mmlu_threshold = 0.7
+    decode_cache_assert = staticmethod(_assert_pp_decode_cached_tokens)
+
+    def test_gsm8k(self):
+        from sglang.test.few_shot_gsm8k import run_eval as run_few_shot_gsm8k
+
+        url = urlparse(self.base_url)
+        args = SimpleNamespace(
+            num_shots=10,
+            data_path=None,
+            num_questions=self.num_gsm8k_questions,
+            max_new_tokens=2048,
+            parallel=self.max_running_requests,
+            host=f"http://{url.hostname}",
+            port=int(url.port),
+        )
+        metrics = run_few_shot_gsm8k(args)
+        print(
+            f"[{self.__class__.__name__}] GSM8K accuracy: {metrics['accuracy']:.3f} "
+            f"(threshold: {self.gsm8k_threshold})"
+        )
+        self.assertGreaterEqual(metrics["accuracy"], self.gsm8k_threshold)
+
+    @classmethod
+    def setUpClass(cls):
+        cls.model = QWEN3_30B_MODEL
+        cls.base_url = DEFAULT_URL_FOR_TEST
+        cls.process = popen_launch_server(
+            cls.model,
+            cls.base_url,
+            timeout=DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
+            other_args=[
+                "--trust-remote-code",
+                "--tp-size",
+                "2",
+                "--pp-size",
+                "2",
+                "--mem-fraction-static",
+                "0.8",
+                "--cuda-graph-max-bs",
+                "32",
+                "--max-running-requests",
+                str(cls.max_running_requests),
+                "--max-total-tokens",
+                "14000",
+                "--disable-piecewise-cuda-graph",
+                "--model-loader-extra-config",
+                '{"enable_multithread_load": true, "num_threads": 64}',
+                "--enable-hierarchical-cache",
+                "--hicache-ratio",
+                "4",
+                "--hicache-write-policy",
+                "write_through",
+                "--hicache-io-backend",
+                cls.hicache_io_backend,
+                "--hicache-mem-layout",
+                cls.hicache_mem_layout,
+            ],
+            env={"SGLANG_ENABLE_UNIFIED_RADIX_TREE": "1"},
+        )
+        cls.input_ids = get_input_ids(cls.model, num_samples=18)
+
+    @classmethod
+    def tearDownClass(cls):
+        kill_process_tree(cls.process.pid)
+
+
+if __name__ == "__main__":
+    unittest.main()

test/registered/unit/mem_cache/test_unified_radix_cache_unittest.py

@@ -2205,7 +2205,7 @@ class UnifiedRadixCacheSuite:
         if storage_backend == "file":
             import sglang.srt.managers.cache_controller as cache_controller
 
-            # The file-backend storage config records TP rank/size.  These unit
+            # The file-backend storage config records TP/PP rank/size.  These unit
             # fixtures run without initializing distributed parallel state, so
             # provide the local single-rank values that the fixture represents.
             tp_rank_patcher = mock.patch.object(
@@ -2214,10 +2214,22 @@ class UnifiedRadixCacheSuite:
             tp_size_patcher = mock.patch.object(
                 cache_controller, "get_tensor_model_parallel_world_size", return_value=1
             )
+            pp_rank_patcher = mock.patch.object(
+                cache_controller, "get_pipeline_model_parallel_rank", return_value=0
+            )
+            pp_size_patcher = mock.patch.object(
+                cache_controller,
+                "get_pipeline_model_parallel_world_size",
+                return_value=1,
+            )
             tp_rank_patcher.start()
             tp_size_patcher.start()
+            pp_rank_patcher.start()
+            pp_size_patcher.start()
             self.addCleanup(tp_rank_patcher.stop)
             self.addCleanup(tp_size_patcher.stop)
+            self.addCleanup(pp_rank_patcher.stop)
+            self.addCleanup(pp_size_patcher.stop)
 
             assert storage_dir is not None, "file backend needs a storage_dir"
             # HiCacheFile reads the directory from this env var.