MySQL Server Plugins MySQL supports an plugin API that enables creation of server plugins. Plugins can be loaded at server startup, or loaded and unloaded at runtime without restarting the server. The plugins supported by this interface include, but are not limited to, storage engines,  INFORMATION_SCHEMA  tables, full-text parser plugins, and server extensions. MySQL distributions include several plugins that implement server extensions: •Plugins for authenticating attempts by clients to connect to MySQL Server. Plugins are available for several authentication protocols. See Section 6.2.17, “Pluggable Authentication” . •A connection-control plugin that enables administrators to introduce an increasing delay after a certain number of consecutive failed client connection attempts. See Section 6.4.2, “The Connection-Control Plugins” . •A password-validation plugin implements password strength policies and assesses the strength of potential passwords. See Section 6.4.3, “The Password Validation Component” . •Semisynchronous replication plugins implement an interface to replication capabilities that permit the source to proceed as long as at least one replica has responded to each transaction. See Section 17.4.10, “Semisynchronous Replication” . •Group Replication enables you to create a highly available distributed MySQL service across a group of MySQL server instances, with data consistency, conflict detection and resolution, and group membership services all built-in. See Chapter 18,  Group Replication . •MySQL Enterprise Edition includes a thread pool plugin that manages connection threads to increase server performance by efficiently managing statement execution threads for large numbers of client connections. See Section 5.6.3, “MySQL Enterprise Thread Pool” . •MySQL Enterprise Edition includes an audit plugin for monitoring and logging of connection and query activity. See Section 6.4.5, “MySQL Enterprise Audit” . •MySQL Enterprise Edition includes a firewall plugin that implements an application-level firewall to enable database administrators to permit or deny SQL statement execution based on matching against allowlists of accepted statement patterns. See Section 6.4.7, “MySQL Enterprise Firewall” . •Query rewrite plugins examine statements received by MySQL Server and possibly rewrite them before the server executes them. See Section 5.6.4, “The Rewriter Query Rewrite Plugin” , and Section 5.6.5, “The ddl_rewriter Plugin” . •Version Tokens enables creation of and synchronization around server tokens that applications can use to prevent accessing incorrect or out-of-date data. Version Tokens is based on a plugin library that implements a  version_tokens  plugin and a set of loadable functions. See Section 5.6.6, “Version Tokens” . •Keyring plugins provide secure storage for sensitive information. See Section 6.4.4, “The MySQL Keyring” . •X Plugin extends MySQL Server to be able to function as a document store. Running X Plugin enables MySQL Server to communicate with clients using the X Protocol, which is designed to expose the ACID compliant storage abilities of MySQL as a document store. See Section 20.5, “X Plugin” . •Clone permits cloning  InnoDB  data from a local or remote MySQL server instance. See Section 5.6.7, “The Clone Plugin” . In MySQL 8.0.24, MySQL Keyring began transitioning from plugins to use the component infrastructure, facilitated using the plugin named  daemon_keyring_proxy_plugin  that acts as a bridge between the plugin and component service APIs. See Section 5.6.8, “The Keyring Proxy Bridge Plugin” . 1073