diff --git a/.vscode/settings.json b/.vscode/settings.json
index 7b6a465..20cccac 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -59,6 +59,8 @@
         "stop_token": "cpp",
         "streambuf": "cpp",
         "cinttypes": "cpp",
-        "typeinfo": "cpp"
+        "typeinfo": "cpp",
+        "any": "cpp",
+        "variant": "cpp"
     }
 }
\ No newline at end of file
diff --git a/lib/mysql.hpp b/lib/mysql.hpp
index 5e21ae8..04e8b1b 100644
--- a/lib/mysql.hpp
+++ b/lib/mysql.hpp
@@ -106,6 +106,7 @@ class MySQL {
     bool run_engin = true;
     future<void> periodic_engin;
     periodical_engine engine_type;
+    function<void(const string&)> on_error;
     
     /**
      * Open one database server connection
@@ -165,6 +166,11 @@ class MySQL {
     */
     void set_connect_trys(const uint32_t _trys);
 
+    /**
+     *  Set callback on error
+     */
+    void set_on_error(function<void(const string&)> _on_error);
+
     /**
      * Execute the SQL statement
     */
diff --git a/src/mysql.cpp b/src/mysql.cpp
index fcf724b..d0e76b3 100644
--- a/src/mysql.cpp
+++ b/src/mysql.cpp
@@ -42,8 +42,9 @@ Connection* marcelb::mysql::MySQL::create_connection() {
          }
       }
       catch (const SQLException &error) {
-         cout << error.what() << endl;
-         // on_error -- ako se ikad impelementira pozovi ga ovdje!
+         if (on_error) {
+            on_error(error.what() + string(", SQL state: ") + error.getSQLState() + string(", Error code: ") + to_string(error.getErrorCode()));
+         }
          usleep(reconnectSleep);
          connect_trys == unlimited ? trys : trys++;
       }         
@@ -78,7 +79,9 @@ bool marcelb::mysql::MySQL::disconnect_connection(Connection* connection) {
          status = !connection->isClosed();
       } 
       catch (const SQLException &error) {
-         cout << error.what() << endl;
+         if (on_error) {
+            on_error(error.what() + string(", SQL state: ") + error.getSQLState() + string(", Error code: ") + to_string(error.getErrorCode()));
+         }
          status = true;
       }
    }
@@ -101,6 +104,10 @@ void marcelb::mysql::MySQL::set_connect_trys(const uint32_t _trys) {
    connect_trys = _trys;
 }
 
+void  marcelb::mysql::MySQL::set_on_error(function<void(const string&)> _on_error) {
+   on_error = _on_error;
+}
+
 Connection* marcelb::mysql::MySQL::occupy_connection() {
    unique_lock<mutex> lock(io);
    while (connection_pool.empty()) {
@@ -136,8 +143,6 @@ marcelb::mysql::MySQL::~MySQL() {
       run_engin = false;
       periodic_engin.get();
    } else {
-      // ne bi bilo loše ubiti periodic nekako?!
-      // iako disconnecta može periodic connect napraviti!!!
       run_engin = false;
    }
    
@@ -147,15 +152,22 @@ marcelb::mysql::MySQL::~MySQL() {
 
 void marcelb::mysql::MySQL::periodic_maintenance() {
    for (size_t i = 0; i < pool_size && run_engin; i++) {
-      Connection *conn = occupy_connection();
-      if (conn->isValid()) {
-         release_connection(conn);
-      } else {
-         if (!conn->isClosed()){
-               conn->close();
+      try {
+         
+         Connection *conn = occupy_connection();
+         if (conn->isValid()) {
+            release_connection(conn);
+         } else {
+            if (!conn->isClosed()){
+                  conn->close();
+            }
+            Connection *n_conn = create_connection();
+            release_connection(n_conn);
+         }
+      } catch (const SQLException &error) {
+         if (on_error) {
+            on_error(error.what() + string(", SQL state: ") + error.getSQLState() + string(", Error code: ") + to_string(error.getErrorCode()));
          }
-         Connection *n_conn = create_connection();
-         release_connection(n_conn);
       }
    }
 }
\ No newline at end of file
diff --git a/test/test.cpp b/test/test.cpp
index 13466f7..4856e52 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -17,6 +17,10 @@ int main() {
         // MySQL mydb("tcp://bitelex.ddns.net:3306", "dinio", "H€r5elfInd1aH@nds", "dinio", 10, periodical_engine::external);
         MySQL mydb("tcp://bitelex.ddns.net:3306", "dinio", "H€r5elfInd1aH@nds", "dinio", 5);
 
+        mydb.set_on_error( [](const string& error) {
+            cout << error << endl;
+        });
+
         // periodic mysql_maintenance ( [&mydb] () {
         //     mydb.periodic_maintenance();
         // }, MYSQL_PERIODIC_INTERNAL_TIME);