diff --git a/include/ylt/coro_io/channel.hpp b/include/ylt/coro_io/channel.hpp
index ad8a8cb9e..bdaec570d 100644
--- a/include/ylt/coro_io/channel.hpp
+++ b/include/ylt/coro_io/channel.hpp
@@ -18,6 +18,7 @@
 
 #include <atomic>
 #include <memory>
+#include <numeric>
 #include <random>
 
 #include "client_pool.hpp"
@@ -77,12 +78,7 @@ class channel {
    }
   */
   struct WRRLoadBlancer {
-    WRRLoadBlancer(const std::vector<std::string>& hosts,
-                   const std::vector<int>& weights)
-        : hosts_(hosts), weights_(weights) {
-      if (hosts_.empty() || weights_.empty()) {
-        throw std::invalid_argument("host/weight list is empty!");
-      }
+    WRRLoadBlancer(const std::vector<int>& weights) : weights_(weights) {
       max_gcd_ = get_max_weight_gcd();
       max_weight_ = get_max_weight();
     }
@@ -101,7 +97,7 @@ class channel {
    private:
     int select_host_with_weight_round_robin() {
       while (true) {
-        wrr_current_ = (wrr_current_ + 1) % hosts_.size();
+        wrr_current_ = (wrr_current_ + 1) % weights_.size();
         if (wrr_current_ == 0) {
           weight_current_ = weight_current_ - max_gcd_;
           if (weight_current_ <= 0) {
@@ -118,15 +114,13 @@ class channel {
       }
     }
 
-    int gcd(int a, int b) { return !b ? a : gcd(b, a % b); }
-
     int get_max_weight_gcd() {
       int res = weights_[0];
       int cur_max = 0, cur_min = 0;
-      for (size_t i = 0; i < hosts_.size(); i++) {
+      for (size_t i = 0; i < weights_.size(); i++) {
         cur_max = (std::max)(res, weights_[i]);
         cur_min = (std::min)(res, weights_[i]);
-        res = gcd(cur_max, cur_min);
+        res = std::gcd(cur_max, cur_min);
       }
       return res;
     }
@@ -135,7 +129,6 @@ class channel {
       return *std::max_element(weights_.begin(), weights_.end());
     }
 
-    std::vector<std::string> hosts_;
     std::vector<int> weights_;
     int max_gcd_ = 0;
     int max_weight_ = 0;
@@ -212,9 +205,15 @@ class channel {
       case load_blance_algorithm::RR:
         lb_worker = RRLoadBlancer{};
         break;
-      case load_blance_algorithm::WRR:
-        lb_worker = WRRLoadBlancer({hosts.begin(), hosts.end()}, weights);
-        break;
+      case load_blance_algorithm::WRR: {
+        if (hosts.empty() || weights.empty()) {
+          throw std::invalid_argument("host/weight list is empty!");
+        }
+        if (hosts.size() != weights.size()) {
+          throw std::invalid_argument("hosts count is not equal with weights!");
+        }
+        lb_worker = WRRLoadBlancer(weights);
+      } break;
       case load_blance_algorithm::random:
       default:
         lb_worker = RandomLoadBlancer{};
diff --git a/src/coro_io/tests/test_channel.cpp b/src/coro_io/tests/test_channel.cpp
index 85ad01c6f..e89adfbec 100644
--- a/src/coro_io/tests/test_channel.cpp
+++ b/src/coro_io/tests/test_channel.cpp
@@ -42,7 +42,8 @@ TEST_CASE("test RR") {
 }
 
 TEST_CASE("test WRR") {
-  SUBCASE("empty hosts or empty weights test") {
+  SUBCASE(
+      "exception tests: empty hosts, empty weights test or count not equal") {
     CHECK_THROWS_AS(
         coro_io::channel<coro_rpc::coro_rpc_client>::create(
             {}, {.lba = coro_io::load_blance_algorithm::WRR}, {2, 1}),
@@ -52,6 +53,11 @@ TEST_CASE("test WRR") {
                         {"127.0.0.1:8801", "127.0.0.1:8802"},
                         {.lba = coro_io::load_blance_algorithm::WRR}),
                     std::invalid_argument);
+
+    CHECK_THROWS_AS(coro_io::channel<coro_rpc::coro_rpc_client>::create(
+                        {"127.0.0.1:8801", "127.0.0.1:8802"},
+                        {.lba = coro_io::load_blance_algorithm::WRR}, {1}),
+                    std::invalid_argument);
   }
 
   coro_rpc::coro_rpc_server server1(1, 8801);