MySQL feature support on Amazon RDS - Amazon Relational Database Service
MySQL major versionsSupported storage enginesUsing memcached and other optionsInnoDB cache warmingInclusive language changes for MySQL 8.4Features not supported

MySQL feature support on Amazon RDS

RDS for MySQL supports most of the features and capabilities of MySQL. Some features might have limited support or restricted privileges.

You can filter new Amazon RDS features on the What's New with Database? page. For Products, choose Amazon RDS. Then search using keywords such as MySQL 2022.

Note

The following lists are not exhaustive.

MySQL feature support on Amazon RDS for MySQL major versions

In the following sections, find information about MySQL feature support on Amazon RDS for MySQL major versions:

For information about supported minor versions of Amazon RDS for MySQL, see Supported MySQL minor versions on Amazon RDS.

MySQL 8.4 support on Amazon RDS

Amazon RDS supports the following new features for your DB instances running MySQL version 8.4 or higher.

  • Cryptographic library – RDS for MySQL replaced OpenSSL with AWS Libcrypto (AWS-LC), which is FIPS 140-3 certified. For more information, see the AWS-LC GitHub repository at https://github.com/aws/aws-lc.

  • TLS changes – RDS for MySQL only supports TLS 1.2 and TLS 1.3. For more information, see SSL/TLS support for MySQL DB instances on Amazon RDS.

  • memcached support – The memcached interface is no longer available on MySQL 8.4. For more information, see MySQL memcached support.

  • Default authentication plugin – The default authentication plugin is caching_sha2_password. For more information, see MySQL default authentication plugin.

  • mysqlpump client utility – The mysqlpump client utility is no longer available in MySQL 8.4. For more information, see Role-based privilege model for RDS for MySQL and mysqldump and mysqlpump in the AWS Prescriptive Guidance.

  • Managed replication stored procedures – When using stored procedures to manage replication with a replication user configured with caching_sha2_password, you must configure TLS by specifying SOURCE_SSL=1. caching_sha2_password is the default authentication plugin for RDS for MySQL 8.4.

  • Parameter behavior changes – The following parameters changed for MySQL 8.4.

  • Deprecated or removed parameters – RDS for MySQL removed the following parameters from parameter groups for MySQL 8.4 DB instances. The innodb_redo_log_capacity parameter now controls the size of the redo log files.

    • innodb_log_file_size

    • innodb_log_files_in_group

  • New default values for parameters – The following parameters have new default values for MySQL 8.4 DB instances:

    • Various MySQL community parameters related to performance changed. For more information, see What is New in MySQL 8.4 since MySQL 8.0.

      We recommend that you test your application's performance on RDS for MySQL 8.4 before migrating a production instance.

    • innodb_purge_threads – The default value is set to the formula LEAST({DBInstanceVCPU/2},4) to prevent the InnoDB history list length from growing too large.

    • group_replication_exit_state_action – The default value is OFFLINE_MODE, which aligns with the default in MySQL Community. For more information, see Considerations and best practices for RDS for MySQL active-active clusters.

    • binlog_format – The default value is ROW, which aligns with the default in MySQL Community. You can modify the parameter for Single-AZ DB instances or Multi-AZ DB instances, but not for Multi-AZ DB clusters. Multi-AZ DB clusters use semisynchronous replication, and when binlog_format is set to MIXED or STATEMENT, replication fails.

  • Inclusive language changes – RDS for MySQL 8.4 includes changes from RDS for MySQL 8.0 related to keywords and system schemas for inclusive language. For more information, see Inclusive language changes for RDS for MySQL 8.4.

For a list of all MySQL 8.4 features and changes, see What Is New in MySQL 8.4 since MySQL 8.0 in the MySQL documentation.

For a list of unsupported features, see MySQL features not supported by Amazon RDS.

Supported storage engines for RDS for MySQL

While MySQL supports multiple storage engines with varying capabilities, not all of them are optimized for recovery and data durability. Amazon RDS fully supports the InnoDB storage engine for MySQL DB instances. Amazon RDS features such as Point-In-Time restore and snapshot restore require a recoverable storage engine and are supported for the InnoDB storage engine only. For more information, see MySQL memcached support.

The Federated Storage Engine is currently not supported by Amazon RDS for MySQL.

For user-created schemas, the MyISAM storage engine does not support reliable recovery and can result in lost or corrupt data when MySQL is restarted after a recovery, preventing Point-In-Time restore or snapshot restore from working as intended. However, if you still choose to use MyISAM with Amazon RDS, snapshots can be helpful under some conditions.

Note

System tables in the mysql schema can be in MyISAM storage.

If you want to convert existing MyISAM tables to InnoDB tables, you can use the ALTER TABLE command (for example, alter table TABLE_NAME engine=innodb;). Bear in mind that MyISAM and InnoDB have different strengths and weaknesses, so you should fully evaluate the impact of making this switch on your applications before doing so.

MySQL 5.1, 5.5, and 5.6 are no longer supported in Amazon RDS. However, you can restore existing MySQL 5.1, 5.5, and 5.6 snapshots. When you restore a MySQL 5.1, 5.5, or 5.6 snapshot, the DB instance is automatically upgraded to MySQL 5.7.

Using memcached and other options with MySQL on Amazon RDS

Most Amazon RDS DB engines support option groups that allow you to select additional features for your DB instance. RDS for MySQL DB instances support the memcached option, a simple, key-based cache. For more information about memcached and other options, see Options for MySQL DB instances. For more information about working with option groups, see Working with option groups.

InnoDB cache warming for MySQL on Amazon RDS

InnoDB cache warming can provide performance gains for your MySQL DB instance by saving the current state of the buffer pool when the DB instance is shut down, and then reloading the buffer pool from the saved information when the DB instance starts up. This bypasses the need for the buffer pool to "warm up" from normal database use and instead preloads the buffer pool with the pages for known common queries. The file that stores the saved buffer pool information only stores metadata for the pages that are in the buffer pool, and not the pages themselves. As a result, the file does not require much storage space. The file size is about 0.2 percent of the cache size. For example, for a 64 GiB cache, the cache warming file size is 128 MiB. For more information on InnoDB cache warming, see Saving and restoring the buffer pool state in the MySQL documentation.

RDS for MySQL DB instances support InnoDB cache warming. To enable InnoDB cache warming, set the innodb_buffer_pool_dump_at_shutdown and innodb_buffer_pool_load_at_startup parameters to 1 in the parameter group for your DB instance. Changing these parameter values in a parameter group will affect all MySQL DB instances that use that parameter group. To enable InnoDB cache warming for specific MySQL DB instances, you might need to create a new parameter group for those instances. For information on parameter groups, see Parameter groups for Amazon RDS.

InnoDB cache warming primarily provides a performance benefit for DB instances that use standard storage. If you use PIOPS storage, you do not commonly see a significant performance benefit.

Important

If your MySQL DB instance does not shut down normally, such as during a failover, then the buffer pool state will not be saved to disk. In this case, MySQL loads whatever buffer pool file is available when the DB instance is restarted. No harm is done, but the restored buffer pool might not reflect the most recent state of the buffer pool prior to the restart. To ensure that you have a recent state of the buffer pool available to warm the InnoDB cache on startup, we recommend that you periodically dump the buffer pool "on demand."

You can create an event to dump the buffer pool automatically and on a regular interval. For example, the following statement creates an event named periodic_buffer_pool_dump that dumps the buffer pool every hour. 

CREATE EVENT periodic_buffer_pool_dump 
ON SCHEDULE EVERY 1 HOUR 
DO CALL mysql.rds_innodb_buffer_pool_dump_now();

For more information on MySQL events, see Event syntax in the MySQL documentation.

Dumping and loading the buffer pool on demand

You can save and load the InnoDB cache "on demand."

Inclusive language changes for RDS for MySQL 8.4

RDS for MySQL 8.4 includes changes from the MySQL 8.4 community edition related to keywords and system schemas for inclusive language. For example, the SHOW REPLICA STATUS command replaces SHOW SLAVE STATUS.

Configuration parameter name changes

The following configuration parameters have new names in RDS for MySQL 8.4.

For compatibility, you can check the parameter names in the mysql client by using either name. You can only use the new names when modifying values in a custom MySQL 8.4 parameter group. For more information, see Default and custom parameter groups.

Name to be removed New or preferred name

init_slave

init_replica

log_slave_updates

log_replica_updates

log_slow_slave_statements

log_slow_replica_statements

rpl_stop_slave_timeout

rpl_stop_replica_timeout

skip_slave_start

skip_replica_start

slave_allow_batching

replica_allow_batching

slave_checkpoint_group

replica_checkpoint_group

slave_checkpoint_period

replica_checkpoint_period

slave_compressed_protocol

replica_compressed_protocol

slave_exec_mode

replica_exec_mode

slave_load_tmpdir

replica_load_tmpdir

slave_max_allowed_packet

replica_max_allowed_packet

slave_net_timeout

replica_net_timeout

slave_parallel_type

replica_parallel_type

slave_parallel_workers

replica_parallel_workers

slave_pending_jobs_size_max

replica_pending_jobs_size_max

slave_preserve_commit_order

replica_preserve_commit_order

slave_skip_errors

replica_skip_errors

slave_sql_verify_checksum

replica_sql_verify_checksum

slave_transaction_retries

replica_transaction_retries

slave_type_conversions

replica_type_conversions

sql_slave_skip_counter

sql_replica_skip_counter

Stored procedure name changes

The following stored procedures have new names in RDS for MySQL 8.4.

For compatibility, you can use either name in the initial RDS for MySQL 8.4 release. The old procedure names are to be removed in a future release. For more information, see Configuring, starting, and stopping binary log (binlog) replication.

Name to be removed New or preferred name

mysql.rds_next_master_log

mysql.rds_next_source_log

mysql.rds_reset_external_master

mysql.rds_reset_external_source

mysql.rds_set_external_master

mysql.rds_set_external_source

mysql.rds_set_external_master_with_auto_position

mysql.rds_set_external_source_with_auto_position

mysql.rds_set_external_master_with_delay

mysql.rds_set_external_source_with_delay

mysql.rds_set_master_auto_position

mysql.rds_set_source_auto_position

MySQL features not supported by Amazon RDS

Amazon RDS doesn't currently support the following MySQL features:

  • Authentication Plugin

  • Error Logging to the System Log

  • InnoDB Tablespace Encryption

  • Password Strength Plugin

  • Persisted system variables

  • Rewriter Query Rewrite Plugin

  • Semisynchronous replication, except for Multi-AZ DB clusters

  • Transportable tablespace

  • X Plugin

To deliver a managed service experience, Amazon RDS doesn't provide shell access to DB instances. It also restricts access to certain system procedures and tables that require advanced privileges. Amazon RDS supports access to databases on a DB instance using any standard SQL client application. Amazon RDS doesn't allow direct host access to a DB instance by using Telnet, Secure Shell (SSH), or Windows Remote Desktop Connection. When you create a DB instance, you are assigned as db_owner for all databases on that instance, and you have all database-level permissions except for those used for backups. Amazon RDS manages backups for you.