diff --git a/rdsn b/rdsn
index 91f9f4e4dc..a975bd65bd 160000
--- a/rdsn
+++ b/rdsn
@@ -1 +1 @@
-Subproject commit 91f9f4e4dc15f80de628820acf994f74a295ffee
+Subproject commit a975bd65bd8f0b10f38d235b1088d0aa9e31bddd
diff --git a/src/server/hotkey_collector.cpp b/src/server/hotkey_collector.cpp
index 4ba9c7b2a3..16c69a63b2 100644
--- a/src/server/hotkey_collector.cpp
+++ b/src/server/hotkey_collector.cpp
@@ -171,10 +171,10 @@ detect_hotkey_result
 hotkey_coarse_data_collector::internal_analysis_method(const std::vector<uint64_t> &captured_keys,
                                                        int threshold)
 {
-
     int data_size = captured_keys.size();
-    dassert(captured_keys.size() > 2, "data_capture_hash_bucket_num is too small");
-
+    dcheck_gt(captured_keys.size(), 2);
+    // empirical rule to calculate hot point of each partition
+    // same algorithm as hotspot_partition_calculator::stat_histories_analyse
     double table_captured_key_sum = 0;
     int hot_index = 0;
     int hot_value = 0;
@@ -197,8 +197,9 @@ hotkey_coarse_data_collector::internal_analysis_method(const std::vector<uint64_
     standard_deviation = sqrt(standard_deviation / (data_size - 2));
     double hot_point = (hot_value - captured_keys_avg_count) / standard_deviation;
     detect_hotkey_result result;
-    hot_point > threshold ? result.coarse_bucket_index = hot_index
-                          : result.coarse_bucket_index = -1;
+    if (hot_point > threshold) {
+        result.coarse_bucket_index = hot_index;
+    }
     return result;
 }
 
diff --git a/src/server/hotkey_collector.h b/src/server/hotkey_collector.h
index 6e903acfd0..532e7207c7 100644
--- a/src/server/hotkey_collector.h
+++ b/src/server/hotkey_collector.h
@@ -28,8 +28,7 @@ class internal_collector_base;
 
 struct detect_hotkey_result
 {
-    int coarse_bucket_index;
-    detect_hotkey_result() : coarse_bucket_index(-1) {}
+    int coarse_bucket_index = -1;
 };
 
 //    hotkey_collector is responsible to find the hot keys after the partition
@@ -105,7 +104,7 @@ class internal_collector_base : public dsn::replication::replica_base
 class hotkey_empty_data_collector : public internal_collector_base
 {
 public:
-    explicit hotkey_empty_data_collector(replica_base *base) : internal_collector_base(base){};
+    explicit hotkey_empty_data_collector(replica_base *base) : internal_collector_base(base) {}
     void capture_data(const dsn::blob &hash_key, uint64_t weight) override {}
     void analyse_data(detect_hotkey_result &result) override {}
 };