MySQL 8 server requested authentication method unknown to the client

MySQL

On a server running MySQL 8 and PHP 7.3, I get the following error [email protected]:~$ php 1.php PHP Warning: mysqli_connect(): The server requested authentication method unknown to the client [caching_sha2_password] in /var/www/html/1.php on line 6 PHP Warning: mysqli_connect(): (HY000/2054): The server requested authentication method unknown to the client in /var/www/html/1.php on line 6 Failed to […]

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Repair MySQL database with mysqlcheck

MySQL

To check and repair all databases in a database run

Forcefully optimize all tables, automatically fixing table errors that may come up.

To check all databases

To analyze all tables in all databases:

To repair all tables in all databases:

To optimize all tables in all databases:

See MySQL […]

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MySQL Unknown collation: ‘utf8mb4_0900_ai_ci’

When restoring a MySQL backup taken on MySQL 8 server, i get following error

To fix this error, open the file in a text editor, find utf8mb4_0900_ai_ci, replace with utf8mb4_unicode_ci. I used following sed command to do the replace.

See MySQL […]

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How to Install MySQL 5.7 on Amazon Linux

MySQL

Amazon Linux 2 come with MariaDB by default. To install MySQL 5.7, install repository with

Install MySQL 5.7 with

Set MySQL to start on boot

Start MySQL server

By default MySQL 5.7 installation generate a temporary password. To find the password, run

To set password and secure the installation, run […]

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MySQL Your password does not satisfy the current policy requirements

MySQL

When i try to create MySQL user on a server, i get following error

This is due to MySQL validate password settings

To fix the error for current session, run

Now password change will work.

If you need it made permanent, then edit MySQL configuration file and add the line under […]

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Change MySQL user password

To change the password for a MySQL user, run

Or via SQL

See MySQL […]

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Reset MySQL root password on Bitnami server

MySQL

To reset MySQL root password on Bitnami server, first check MySQL server version you are running.

Create a file

Add following text For MySQL 5.7 or MySQL 8

For MySQL 5.6

In above code, replace NEW_PASSWORD with your new MySQL root password. Stop MySQL

Reset MySQL root password by running […]

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MariaDB Change Open Files Limit

When using systemctl, you can set value for open_files_limit in my.cnf file. Default installation of MariaDB 10 have open_files_limit set to 16384. To increase value for open_files_limit, create file

Add

Reload systemctl

Restart mariadb

After doing this, it get changed to 32184 instead of 1048576 we specified in limitnofile.conf To fix […]

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MySQL Can’t create new tempfile

When i try to repair a crashed database table, i get error

Check the table with myisamcheck

It reported some errros. To fix, run

When i run, i get following error

Since the error said “Can’t create new tempfile”, i checked disk usage to make sure disk is not full. Since […]

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