Hi, I have simple lua script: cdb = require("cdb") function read_auth() local db = cdb.open("/etc/mysql/proxy/data.cdb") local value = db:get(proxy.connection.client.username) db:close() if value == nil then proxy.response.type = proxy.MYSQLD_PACKET_ERR proxy.response.errmsg = "Access denied" return proxy.PROXY_SEND_RESULT end end Format of data: username1 1 username2 1 and so on. Unfortunately after upgrade from mariadb-10.1 to mariadb-10.3 on buster mysql-proxy is defunct. Cannot get "mysql prompt". I tried to replace mysql-proxy by maxscale-2.3.6, but without success. Failed to load users from server 'server1': Lost connection to MySQL server during query Aborted connection 8578832 to db: 'mysql' user: 'debian-sys-maint' host: 'localhost' (Got an error writing communication packets) Note that there is a few hundreds thousands users in mysql.user, but in data.cdb only a few hundreds. Could you point me to the right place, where to find info how to fix mysql-proxy, or configure maxscale, or some alternative to both? Witold Filipczyk