Hi, I coped with this error but I don't know how to fix it. When I upload a new problem to the system, it's show the message: "Error: problem.externalid: A problem with the same `externalid` already exists - is this a duplicate?" Even I checked that in my problem package, I used a new probid. It's strange with this version compare with the logic on version 5.3.2 Regards, Trần Bình Dương (Mr) IT Lecturer Software Engineering Department , FPT University 29th Kilometer Thang Long Boulevard, Thach Hoa commune, Thach That Province, Education and Training Area, Hoa Lac High Tech Park, Ha Noi Mobile:(+84) 936168165 Skype: avn_duong.tb E-mail: duongtb@fe.edu.vn Website: .... ________________________________ Từ: Nicky Gerritsen <nickygerritsen@me.com> Đã gửi: 31 Tháng Mười 2020 6:51 CH Đến: domjudge-devel@domjudge.org <domjudge-devel@domjudge.org>; Tran Binh Duong (FE FPTU HN) <DuongTB@fe.edu.vn> Chủ đề: Re: Trả lời: About: strange phenomenon on domjudge with system which has a hardware load balancer configuration. You can choose. I have never set it up with symfony so I can’t really help. Hopefully google will help you Nicky On 31 Oct 2020, 12:50 +0100, Tran Binh Duong (FE FPTU HN) <DuongTB@fe.edu.vn>, wrote: Hi Nicky, Thanks for your response, I read the document at https://symfony.com/doc/current/session/database.html [https://symfony.com/images/opengraph/symfony.png]<https://symfony.com/doc/current/session/database.html> Store Sessions in a Database (Symfony Docs)<https://symfony.com/doc/current/session/database.html> These are parameters that you can configure: db_table (default sessions): The name of the session table in your database; db_username: (default: '') The username used to connect when using the PDO configuration (when using the connection based on the DATABASE_URL env var, it overrides the username defined in the env var). db_password: (default: '') The password used to connect when using the ... symfony.com But because I am not familiar with symfony, so I don't understand the structure and the method when developing and configuring in Symfony. Therefore, the content of the document is quite difficult to me to make sure how to start. Should I use only PHP to complete the configuration or I have to configure in three kind of document including YAML, XML and PHP? If I use only PHP, what should I do? Just follow the guide on TAB PHP is enough? Regards, Trần Bình Dương (Mr) IT Lecturer Software Engineering Department , FPT University 29th Kilometer Thang Long Boulevard, Thach Hoa commune, Thach That Province, Education and Training Area, Hoa Lac High Tech Park, Ha Noi Mobile:(+84) 936168165 Skype: avn_duong.tb E-mail: duongtb@fe.edu.vn Website: .... ________________________________ Từ: Nicky Gerritsen <nickygerritsen@me.com> Đã gửi: 31 Tháng Mười 2020 5:52 CH Đến: domjudge-devel@domjudge.org <domjudge-devel@domjudge.org>; Tran Binh Duong (FE FPTU HN) <DuongTB@fe.edu.vn> Chủ đề: Re: About: strange phenomenon on domjudge with system which has a hardware load balancer configuration. You need to share sessions between the web servers. See https://github.com/DOMjudge/domjudge/wiki/Scaling-and-load-testing Nicky On 31 Oct 2020, 11:50 +0100, Tran Binh Duong (FE FPTU HN) <DuongTB@fe.edu.vn>, wrote: Hi all, Our contestants feedback about the error as follow: “Invalid CSRF token”, moreover contestants were frequently experienced with kicking out phenomenon and very hard to log back into the system. Our configuration is briefly depicted as follow: / domserver 1 \ Client ——> HW load balancer < >== Mysql DB \ domserver 2 / Please give me some advice to solve the issue. Trần Bình Dương (Mr) IT Lecturer Software Engineering Department , FPT University 29th Kilometer Thang Long Boulevard, Thach Hoa commune, Thach That Province, Education and Training Area, Hoa Lac High Tech Park, Ha Noi Mobile:(+84) 936168165 Skype: avn_duong.tb E-mail: duongtb@fe.edu.vn Website: .... _______________________________________________ DOMjudge-devel mailing list DOMjudge-devel@domjudge.org https://www.domjudge.org/mailman/listinfo/domjudge-devel