LAPP is Apache, PostgreSQL and PHP for Linux. It’s like LAMP (Apache, MySQL (using MariaDB) and PHP), but instead of MySQL here has been used PostgreSQL. To install LAPP on Centos 7 follow the steps below…

For restarting PostgreSQL you can use the commands “stop” and “start” or “restart” but into cases, you must be a “super user” (use the command “sudo” or “su”). Let’s see how to restart PostgreSQL in Red Hat system:

About LAPP: It includes four of the most popular software components Apache, PostgreSQL, and PHP. The LAMP is used to develop forums, blogs, and so on. Let’s start the installation of LAPP on your “Debian 9”.

Why we become the error: [53300] FATAL: remaining connection slots are reserved for non-replication superuser connections