diff --git a/src/dist/replication/meta_server/app_env_validator.cpp b/src/dist/replication/meta_server/app_env_validator.cpp
index 6435011fe5..5d2e010a8d 100644
--- a/src/dist/replication/meta_server/app_env_validator.cpp
+++ b/src/dist/replication/meta_server/app_env_validator.cpp
@@ -1,5 +1,4 @@
 /*
-
  * The MIT License (MIT)
  *
  * Copyright (c) 2015 Microsoft Corporation
@@ -25,7 +24,6 @@
  * THE SOFTWARE.
  */
 
-#include <regex>
 #include <dist/replication/common/replication_common.h>
 #include <fmt/format.h>
 #include <dsn/utility/string_conv.h>
@@ -106,7 +104,7 @@ bool app_env_validator::validate_app_env(const std::string &env_name,
         return true;
     }
 
-    hint_message = fmt::format("The env of {} is not supported", env_name);
+    hint_message = fmt::format("app_env \"{}\" is not supported", env_name);
     return false;
 }
 
diff --git a/src/dist/replication/meta_server/app_env_validator.h b/src/dist/replication/meta_server/app_env_validator.h
index 5f2f33f5ae..1bdb41a18e 100644
--- a/src/dist/replication/meta_server/app_env_validator.h
+++ b/src/dist/replication/meta_server/app_env_validator.h
@@ -31,7 +31,7 @@
 namespace dsn {
 namespace replication {
 
-class app_env_validator : public ::dsn::utils::singleton<app_env_validator>
+class app_env_validator : public utils::singleton<app_env_validator>
 {
 public:
     app_env_validator() { register_all_validators(); }
diff --git a/src/dist/replication/meta_server/server_state.h b/src/dist/replication/meta_server/server_state.h
index 89f1894123..f4fb5fa7de 100644
--- a/src/dist/replication/meta_server/server_state.h
+++ b/src/dist/replication/meta_server/server_state.h
@@ -339,9 +339,6 @@ class server_state
     perf_counter_wrapper _recent_update_config_count;
     perf_counter_wrapper _recent_partition_change_unwritable_count;
     perf_counter_wrapper _recent_partition_change_writable_count;
-
-    std::map<std::string, std::function<bool(const std::string &, std::string &)>>
-        env_check_functions;
 };
 
 } // namespace replication