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•An SSL certificate and key files are generated in the data directory. 

• validate_password  is installed and enabled. 

•A superuser account ’root’@’localhost’  is created. A password for the superuser is set and stored in the error log file. To reveal it, use the following command for RHEL, Oracle Linux, CentOS, and Fedora systems: 

shell> sudo grep ’temporary password’ /var/log/mysqld.log 

Use the following command for SLES systems: 

shell> sudo grep ’temporary password’ /var/log/mysql/mysqld.log 

The next step is to log in with the generated, temporary password and set a custom password for the superuser account: 

shell> mysql -uroot -p 

mysql> ALTER USER ’root’@’localhost’ IDENTIFIED BY ’MyNewPass4!’; 

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## Note 

validate_password  is installed by default. The default password policy implemented by validate_password  requires that passwords contain at least one uppercase letter, one lowercase letter, one digit, and one special character, and that the total password length is at least 8 characters. 

If something goes wrong during installation, you might find debug information in the error log file /var/ log/mysqld.log . 

For some Linux distributions, it might be necessary to increase the limit on number of file descriptors available to mysqld . See Section B.3.2.16, “File Not Found and Similar Errors” 

Installing Client Libraries from Multiple MySQL Versions.  It is possible to install multiple client library versions, such as for the case that you want to maintain compatibility with older applications linked against previous libraries. To install an older client library, use the --oldpackage  option with rpm . For example, to install mysql-community-libs-5.5  on an EL6 system that has libmysqlclient.21  from MySQL 8.0, use a command like this: 

shell> rpm --oldpackage -ivh mysql-community-libs-5.5.50-2.el6.x86_64.rpm 

Debug Package.  A special variant of MySQL Server compiled with the debug package has been included in the server RPM packages. It performs debugging and memory allocation checks and produces a trace file when the server is running. To use that debug version, start MySQL with /usr/sbin/mysqld- debug , instead of starting it as a service or with /usr/sbin/mysqld . See Section 5.9.4, “The DBUG Package”  for the debug options you can use. 

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## Note 

The default plugin directory for debug builds changed from /usr/lib64/mysql/ plugin  to /usr/lib64/mysql/plugin/debug  in MySQL 8.0.4. Previously, it was necessary to change plugin_dir  to /usr/lib64/mysql/plugin/debug for debug builds. 

Rebuilding RPMs from source SRPMs.  Source code SRPM packages for MySQL are available for download. They can be used as-is to rebuild the MySQL RPMs with the standard rpmbuild  tool chain. 

