From 7769a34c82553ba473bbb431658c0b73de823f09 Mon Sep 17 00:00:00 2001
From: Linxiushen <1787979356@qq.com>
Date: Mon, 21 Sep 2026 21:13:48 +0800
Subject: [PATCH] fix(config): reject non-positive `explorer_sync_interval` /
 `trainer_sync_interval`

SynchronizerConfigValidator asserts that `sync_interval` is positive, but
the two per-role overrides that default to it, `explorer_sync_interval` and
`trainer_sync_interval`, had no range check. Setting either to 0 passed
validation and then crashed later in IntervalConfigValidator with
`ZeroDivisionError: integer modulo by zero` (config_validator.py:895),
instead of failing with a clear message.

Add the same positivity assertions right after the two set_if_none calls,
so inherited values are checked as well. Configurations with positive
values are unaffected; none of the shipped example configs set these
fields.
---
 tests/common/config_test.py        | 10 ++++++++++
 trinity/common/config_validator.py |  6 ++++++
 2 files changed, 16 insertions(+)

diff --git a/tests/common/config_test.py b/tests/common/config_test.py
index 3ed9c797b7e..a1c8a31d42e 100644
--- a/tests/common/config_test.py
+++ b/tests/common/config_test.py
@@ -135,6 +135,16 @@ def test_multinode_vllm_requires_full_node_occupancy(self):
         with self.assertRaisesRegex(ValueError, "to be a multiple of"):
             config.check_and_update()
 
+    def test_sync_interval_overrides_must_be_positive(self):
+        for field in ("explorer_sync_interval", "trainer_sync_interval"):
+            with self.subTest(field=field):
+                config = get_template_config()
+                config.synchronizer.sync_interval = 4
+                setattr(config.synchronizer, field, 0)
+
+                with self.assertRaisesRegex(AssertionError, f"`{field}` must be positive"):
+                    config.check_and_update()
+
     def test_load_default_config(self):
         config = get_template_config()
         config.buffer.batch_size = 8
diff --git a/trinity/common/config_validator.py b/trinity/common/config_validator.py
index abc38b1332f..551e17af388 100644
--- a/trinity/common/config_validator.py
+++ b/trinity/common/config_validator.py
@@ -868,6 +868,12 @@ def validate(self, config: Config) -> None:
             config.synchronizer, "explorer_sync_interval", config.synchronizer.sync_interval
         )
         set_if_none(config.synchronizer, "trainer_sync_interval", config.synchronizer.sync_interval)
+        assert (
+            config.synchronizer.explorer_sync_interval > 0
+        ), "`explorer_sync_interval` must be positive."
+        assert (
+            config.synchronizer.trainer_sync_interval > 0
+        ), "`trainer_sync_interval` must be positive."
 
 
 class IntervalConfigValidator(ConfigValidator):