Base de Conhecimento

Introduction

MySQL is an open-source database management system, commonly installed as part of the popular LAMP(Linux, Apache, MySQL, PHP/Python/Perl) stack. It uses a relational database and SQL (Structured Query Language) to manage its data.

The short version of the installation is simple: update your package index, install the mysql-serverpackage, and then run the included security script.

• sudo apt-get update
• sudo apt-get install mysql-server
• sudo mysql_secure_installation

This tutorial will explain how to install MySQL version 5.7 on a Ubuntu 16.04 server. However, if you're looking to update an existing MySQL installation to version 5.7, you can read this MySQL 5.7 update guide instead.

Prerequisites

To follow this tutorial, you will need:

• One Ubuntu 16.04 server set up by following this initial server setup guide, including a sudo non-root user and a firewall.

Step 1 — Installing MySQL

On Ubuntu 16.04, only the latest version of MySQL is included in the APT package repository by default. At the time of writing, that's MySQL 5.7

To install it, simply update the package index on your server and install the default package with apt-get.

• sudo apt-get update
• sudo apt-get install mysql-server

You'll be prompted to create a root password during the installation. Choose a secure one and make sure you remember it, because you'll need it later. Next, we'll finish configuring MySQL.

Step 2 — Configuring MySQL

For fresh installations, you'll want to run the included security script. This changes some of the less secure default options for things like remote root logins and sample users. On older versions of MySQL, you needed to initialize the data directory manually as well, but this is done automatically now.

Run the security script.

• sudo mysql_secure_installation

This will prompt you for the root password you created in Step 1. You can press Y and then ENTER to accept the defaults for all the subsequent questions, with the exception of the one that asks if you'd like to change the root password. You just set it in Step 1, so you don't have to change it now.

To initialize the MySQL data directory, you would use mysql_install_db for versions before 5.7.6, and mysqld --initialize for 5.7.6 and later. However, if you installed MySQL from the Debian distribution, like in Step 1, the data directory was initialized automatically; you don't have to do anything. If you try running the command anyway, you'll see the following error:

2016-03-07T20:11:15.998193Z 0 [ERROR] --initialize specified but the data directory has files in it. Aborting.

Finally, let's test the MySQL installation.

Step 3 — Testing MySQL

Regardless of how you installed it, MySQL should have started running automatically. To test this, check its status.

• systemctl status mysql.service

You'll see output similar to the following:

● mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: en
   Active: active (running) since Wed 2016-11-23 21:21:25 UTC; 30min ago
 Main PID: 3754 (mysqld)
    Tasks: 28
   Memory: 142.3M
      CPU: 1.994s
   CGroup: /system.slice/mysql.service
           └─3754 /usr/sbin/mysqld

If MySQL isn't running, you can start it with sudo systemctl mysql start.

For an additional check, you can try connecting to the database using the mysqladmin tool, which is a client that lets you run administrative commands. For example, this command says to connect to MySQL as root (-u root), prompt for a password (-p), and return the version.

• mysqladmin -p -u root version

You should see output similar to this:

mysqladmin  Ver 8.42 Distrib 5.7.16, for Linux on x86_64
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Server version      5.7.16-0ubuntu0.16.04.1
Protocol version    10
Connection      Localhost via UNIX socket
UNIX socket     /var/run/mysqld/mysqld.sock
Uptime:         30 min 54 sec

Threads: 1  Questions: 12  Slow queries: 0  Opens: 115  Flush tables: 1  Open tables: 34  Queries per second avg: 0.006

This means MySQL is up and running.