15.1.5 ALTER INSTANCE Statement

ALTER INSTANCE instance_action

instance_action: {
  | {ENABLE|DISABLE} INNODB REDO_LOG
  | ROTATE INNODB MASTER KEY
  | ROTATE BINLOG MASTER KEY
  | RELOAD TLS
      [FOR CHANNEL {mysql_main | mysql_admin}]
      [NO ROLLBACK ON ERROR]
  | RELOAD KEYRING
}

ALTER INSTANCE defines actions applicable to a MySQL server instance. The statement supports these actions:

• ALTER INSTANCE {ENABLE | DISABLE} INNODB REDO_LOG

  This action enables or disables InnoDB redo logging. Redo logging is enabled by default. This feature is intended only for loading data into a new MySQL instance. The statement is not written to the binary log.

  Warning

  Do not disable redo logging on a production system. While it is permitted to shut down and restart the server while redo logging is disabled, an unexpected server stoppage while redo logging is disabled can cause data loss and instance corruption.

  An ALTER INSTANCE [ENABLE|DISABLE] INNODB REDO_LOG operation requires an exclusive backup lock, which prevents other ALTER INSTANCE operations from executing concurrently. Other ALTER INSTANCE operations must wait for the lock to be released before executing.

  For more information, see Disabling Redo Logging.

• ALTER INSTANCE ROTATE INNODB MASTER KEY

  This action rotates the master encryption key used for InnoDB tablespace encryption. Key rotation requires the ENCRYPTION_KEY_ADMIN or SUPER privilege. To perform this action, a keyring plugin must be installed and configured. For instructions, see Section 8.4.4, “The MySQL Keyring”.

  ALTER INSTANCE ROTATE INNODB MASTER KEY supports concurrent DML. However, it cannot be run concurrently with CREATE TABLE ... ENCRYPTION or ALTER TABLE ... ENCRYPTION operations, and locks are taken to prevent conflicts that could arise from concurrent execution of these statements. If one of the conflicting statements is running, it must complete before another can proceed.

  ALTER INSTANCE ROTATE INNODB MASTER KEY statements are written to the binary log so that they can be executed on replicated servers.

  For additional ALTER INSTANCE ROTATE INNODB MASTER KEY usage information, see Section 17.13, “InnoDB Data-at-Rest Encryption”.

• ALTER INSTANCE ROTATE BINLOG MASTER KEY

  This action rotates the binary log master key used for binary log encryption. Key rotation for the binary log master key requires the BINLOG_ENCRYPTION_ADMIN or SUPER privilege. The statement cannot be used if the binlog_encryption system variable is set to OFF. To perform this action, a keyring plugin must be installed and configured. For instructions, see Section 8.4.4, “The MySQL Keyring”.

  ALTER INSTANCE ROTATE BINLOG MASTER KEY actions are not written to the binary log and are not executed on replicas. Binary log master key rotation can therefore be carried out in replication environments including a mix of MySQL versions. To schedule regular rotation of the binary log master key on all applicable source and replica servers, you can enable the MySQL Event Scheduler on each server and issue the ALTER INSTANCE ROTATE BINLOG MASTER KEY statement using a CREATE EVENT statement. If you rotate the binary log master key because you suspect that the current or any of the previous binary log master keys might have been compromised, issue the statement on every applicable source and replica server, which enables you to verify immediate compliance.

  For additional ALTER INSTANCE ROTATE BINLOG MASTER KEY usage information, including what to do if the process does not complete correctly or is interrupted by an unexpected server halt, see Section 19.3.2, “Encrypting Binary Log Files and Relay Log Files”.

• ALTER INSTANCE RELOAD TLS

  This action reconfigures a TLS context from the current values of the system variables that define the context. It also updates the status variables that reflect the active context values. This action requires the CONNECTION_ADMIN privilege. For additional information about reconfiguring the TLS context, including which system and status variables are context-related, see Server-Side Runtime Configuration and Monitoring for Encrypted Connections.

  By default, the statement reloads the TLS context for the main connection interface. If the FOR CHANNEL clause is given, the statement reloads the TLS context for the named channel: mysql_main for the main connection interface, mysql_admin for the administrative connection interface. For information about the different interfaces, see Section 7.1.12.1, “Connection Interfaces”. The updated TLS context properties are exposed in the Performance Schema tls_channel_status table. See Section 29.12.22.9, “The tls_channel_status Table”.

  Updating the TLS context for the main interface may also affect the administrative interface because unless some nondefault TLS value is configured for that interface, it uses the same TLS context as the main interface.

  Note

  When you reload the TLS context, OpenSSL reloads the file containing the CRL (certificate revocation list) as part of the process. If the CRL file is large, the server allocates a large chunk of memory (ten times the file size), which is doubled while the new instance is being loaded and the old one has not yet been released. The process resident memory is not immediately reduced after a large allocation is freed, so if you issue the ALTER INSTANCE RELOAD TLS statement repeatedly with a large CRL file, the process resident memory usage may grow as a result of this.

  By default, the RELOAD TLS action rolls back with an error and has no effect if the configuration values do not permit creation of the new TLS context. The previous context values continue to be used for new connections. If the optional NO ROLLBACK ON ERROR clause is given and the new context cannot be created, rollback does not occur. Instead, a warning is generated and encryption is disabled for new connections on the interface to which the statement applies.

  ALTER INSTANCE RELOAD TLS statements are not written to the binary log (and thus are not replicated). TLS configuration is local and depends on local files not necessarily present on all servers involved.

• ALTER INSTANCE RELOAD KEYRING

  If a keyring component is installed, this action tells the component to re-read its configuration file and reinitialize any keyring in-memory data. If you modify the component configuration at runtime, the new configuration does not take effect until you perform this action. Keyring reloading requires the ENCRYPTION_KEY_ADMIN privilege.

  This action enables reconfiguring only the currently installed keyring component. It does not enable changing which component is installed. For example, if you change the configuration for the installed keyring component, ALTER INSTANCE RELOAD KEYRING causes the new configuration to take effect. On the other hand, if you change the keyring component named in the server manifest file, ALTER INSTANCE RELOAD KEYRING has no effect and the current component remains installed.

  ALTER INSTANCE RELOAD KEYRING statements are not written to the binary log (and thus are not replicated).