Archives for October 2019

This post focusses on understanding why the "system user" is seen in SHOW PROCESSLIST and the information_schema.PROCESSLIST view on replication slaves. The system user is not a real user and is used for display purposes only to indicate it is the system performing the task. It is used by the I/O and SQL threads (connection and applier threads) on a replication slave. These threads are handled by the system and not by a login user. The system user can for example be seen in the output of … [Read more...] about What is the purpose of “system user” in MySQL Replication

The are a few users created by MySQL for various purposes ranging from handling the replication to be the definer for sys schema objects. The users are summarized in the following table: UserFirst VersionLast VersionFeatureComments system user(At least since 5.0) ReplicationUsed for the I/O and SQL threads (connection and applier threads). This is not a real user, but just a label used in SHOW PROCESSLIST and similar places to indicate it is an internal user. There is no way to … [Read more...] about What are Reserved User Accounts in MySQL

This post explains why the mysql.sys@localhost user exists and what it is used for. The mysql.sys@localhost user is a system user used as the definer for view, procedures, and functions in the sys schema. It was added in MySQL 5.7.9 to avoid issues if the DBA renames the root@localhost user. See also MySQL sys Schema in the Reference Manual. The following applies to the mysql.sys@localhost user: 1. It is a required user as long as the sys schema is installed. Please do not drop the … [Read more...] about What is the purpose of “mysql.sys@localhost” user

The primary function of the MySQL authorization system is to associate an authenticated user with privileges on a database, such as SELECT, INSERT, UPDATE, and DELETE. The authorization system’s functionality includes the ability to have anonymous users and to enable specific functions such as LOAD DATA INFILE and various administrative operations. This authorization ensures that users can perform only the operations for which they have been granted appropriate privileges. Determining … [Read more...] about Understanding MySQL Privileges

MySQL supports a number of authentication mechanisms that are available through pluggable authentication. MySQL uses a number of algorithms to encrypt passwords stored in the user table: The mysql_native_password plugin implements the standard password format, a 41-byte-wide hash. The mysql_old_password plugin implements an older format that is less secure, being 16 bytes wide. The sha256_password plugin implements the SHA-256 hashing algorithm widely used in secure computing. The … [Read more...] about Understanding MySQL Pluggable Authentication

Managing users in MySQL gives you the ability to control what users can and cannot do. Create user accounts with different privileges that are appropriate to their function. Avoid using the root account - Constrain compromised applications and protect against mistakes during routine maintenance. Ensure data integrity by proper assignment of individual user privileges. Permit authorized users to do their work. Prevent unauthorized users from accessing data beyond their privileges. User … [Read more...] about Beginners Guide to MySQL User Management