Simplify flush_cache: reject concurrent requests, remove client-side retry (#21490)

test/manual/hicache/test_disaggregation_hicache.py

@@ -1,7 +1,6 @@
 import os
 import random
 import tempfile
-import time
 import unittest
 from typing import Dict
 
@@ -14,7 +13,6 @@ from sglang.test.server_fixtures.disaggregation_fixture import (
 from sglang.test.test_utils import (
     DEFAULT_MODEL_NAME_FOR_TEST,
     DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
-    flush_cache_with_retry,
     popen_launch_pd_server,
 )
 
@@ -116,8 +114,12 @@ class DisaggregationHiCacheBase(PDDisaggregationServerBase):
         self.send_request(self.gen_prompt(1), max_tokens=150)
 
         # Flush device cache to force remote storage access.
-        time.sleep(2)
-        flush_cache_with_retry(self.prefill_url)
+        res = requests.post(
+            f"{self.prefill_url}/flush_cache",
+            params={"timeout": 30},
+            timeout=40,
+        )
+        res.raise_for_status()
 
 
 class TestDisaggregationPrefillWithHiCache(DisaggregationHiCacheBase):

test/manual/hicache/test_pp_with_hicache.py

@@ -18,7 +18,6 @@ from sglang.test.test_utils import (
     DEFAULT_MODEL_NAME_FOR_TEST,
     DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
     find_available_port,
-    flush_cache_with_retry,
     popen_launch_server,
 )
 
@@ -180,8 +179,13 @@ class TestPPWithHiCache(unittest.TestCase):
 
         return False
 
-    def flush_cache(self) -> bool:
-        return flush_cache_with_retry(self.base_url)
+    def flush_cache(self):
+        res = requests.post(
+            f"{self.base_url}/flush_cache",
+            params={"timeout": 30},
+            timeout=40,
+        )
+        res.raise_for_status()
 
     def test_eval_accuracy(self):
         args = SimpleNamespace(
@@ -197,8 +201,7 @@ class TestPPWithHiCache(unittest.TestCase):
         metrics_initial = run_eval_few_shot_gsm8k(args)
         self.assertGreater(metrics_initial["accuracy"], 0.6)
 
-        self.assertTrue(self.flush_cache())
-        time.sleep(2)
+        self.flush_cache()
 
         metrics_cached = run_eval_few_shot_gsm8k(args)
         self.assertGreater(metrics_cached["accuracy"], 0.6)