# Aurora MySQL configuration parameters You manage your Amazon Aurora MySQL DB cluster in the same way that you manage other Amazon RDS DB instances, by using parameters in a DB parameter group. Amazon Aurora differs from other DB engines in that you have a DB cluster that contains multiple DB instances. As a result, some of the parameters that you use to manage your Aurora MySQL DB cluster apply to the entire cluster. Other parameters apply only to a particular DB instance in the DB cluster. To manage cluster-level parameters, use DB cluster parameter groups. To manage instance-level parameters, use DB parameter groups. Each DB instance in an Aurora MySQL DB cluster is compatible with the MySQL database engine. However, you apply some of the MySQL database engine parameters at the cluster level, and you manage these parameters using DB cluster parameter groups. You can't find cluster-level parameters in the DB parameter group for an instance in an Aurora DB cluster. A list of cluster-level parameters appears later in this topic. You can manage both cluster-level and instance-level parameters using the AWS Management Console, the AWS CLI, or the Amazon RDS API. You use separate commands for managing cluster-level parameters and instance-level parameters. For example, you can use the [modify-db-cluster-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-cluster-parameter-group.html) CLI command to manage cluster-level parameters in a DB cluster parameter group. You can use the [modify-db-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/rds/modify-db-parameter-group.html) CLI command to manage instance-level parameters in a DB parameter group for a DB instance in a DB cluster. You can view both cluster-level and instance-level parameters in the console, or by using the CLI or RDS API. For example, you can use the [describe-db-cluster-parameters](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-cluster-parameters.html) AWS CLI command to view cluster-level parameters in a DB cluster parameter group. You can use the [describe-db-parameters](https://docs.aws.amazon.com/cli/latest/reference/rds/describe-db-parameters.html) CLI command to view instance-level parameters in a DB parameter group for a DB instance in a DB cluster. **Note** Each [default parameter group](USER_WorkingWithParamGroups.md) contains the default values for all parameters in the parameter group. If the parameter has "engine default" for this value, see the version-specific MySQL or PostgreSQL documentation for the actual default value. Unless otherwise noted, parameters listed in the following tables are valid for Aurora MySQL versions 2 and 3. For more information about DB parameter groups, see [Parameter groups for Amazon Aurora](USER_WorkingWithParamGroups.md). **Topics** + [ ## Cluster-level parameters ](#AuroraMySQL.Reference.Parameters.Cluster) + [ ## Instance-level parameters ](#AuroraMySQL.Reference.Parameters.Instance) + [ ## MySQL parameters that don't apply to Aurora MySQL ](#AuroraMySQL.Reference.Parameters.Inapplicable) ## Cluster-level parameters The following table shows all of the parameters that apply to the entire Aurora MySQL DB cluster. | Parameter name | Modifiable | Notes | | --- | --- | --- | | `aurora_binlog_read_buffer_size` | Yes | Only affects clusters that use binary log (binlog) replication. For information about binlog replication, see [Replication between Aurora and MySQL or between Aurora and another Aurora DB cluster (binary log replication)](AuroraMySQL.Replication.MySQL.md). Removed from Aurora MySQL version 3. | | `aurora_binlog_replication_max_yield_seconds` | Yes | Only affects clusters that use binary log (binlog) replication. For information about binlog replication, see [Replication between Aurora and MySQL or between Aurora and another Aurora DB cluster (binary log replication)](AuroraMySQL.Replication.MySQL.md). | | `aurora_binlog_replication_sec_index_parallel_workers` | Yes | Sets the total number of parallel threads available to apply secondary index changes when replicating transactions for large tables with more than one secondary index. The parameter is set to `0` (disabled) by default. This parameter is available in Aurora MySQL version 306 and higher. For more information, see [Optimizing binary log replication for Aurora MySQL](binlog-optimization.md). | | `aurora_binlog_use_large_read_buffer` | Yes | Only affects clusters that use binary log (binlog) replication. For information about binlog replication, see [Replication between Aurora and MySQL or between Aurora and another Aurora DB cluster (binary log replication)](AuroraMySQL.Replication.MySQL.md). Removed from Aurora MySQL version 3. | | `aurora_disable_hash_join` | Yes | Set this parameter to `ON` to turn off hash join optimization in Aurora MySQL version 2.09 or higher. It isn't supported for version 3. For more information, see [Parallel query for Amazon Aurora MySQL](aurora-mysql-parallel-query.md). | | `aurora_enable_replica_log_compression` | Yes | For more information, see [Performance considerations for Amazon Aurora MySQL replication](AuroraMySQL.Replication.md#AuroraMySQL.Replication.Performance). Doesn't apply to clusters that are part of an Aurora global database. Removed from Aurora MySQL version 3. | | `aurora_enable_repl_bin_log_filtering` | Yes | For more information, see [Performance considerations for Amazon Aurora MySQL replication](AuroraMySQL.Replication.md#AuroraMySQL.Replication.Performance). Doesn't apply to clusters that are part of an Aurora global database. Removed from Aurora MySQL version 3. | | `aurora_enable_staggered_replica_restart` | Yes | This setting is available in Aurora MySQL version 3, but it isn't used. | | `aurora_enable_zdr` | Yes | This setting is turned on by default in Aurora MySQL 2.10 and higher. | | `aurora_in_memory_relaylog` | Yes | Sets the in memory relay log mode. You can use this feature on binlog replicas to improve binary log replication performance. To turn this feature off, set the parameter to OFF. To turn this feature on, set the parameter to ON. | | `aurora_enhanced_binlog` | Yes | Set the value of this parameter to 1 to turn on the enhanced binlog in Aurora MySQL version 3.03.1 and higher. For more information, see [Setting up enhanced binlog for Aurora MySQL](AuroraMySQL.Enhanced.binlog.md). | | `aurora_full_double_precision_in_json` | Yes | Set the value of this parameter to enable the parsing of floating point numbers in JSON documents with full precision. | | `aurora_jemalloc_background_thread` | Yes | Use this parameter to enable a background thread to perform memory maintenance operations. The allowed values are `0` (disabled) and `1` (enabled). The default value is `0`. This parameter applies to Aurora MySQL version 3.05 and higher. | | `aurora_jemalloc_dirty_decay_ms` | Yes | Use this parameter to retain freed memory for a certain amount of time (in milliseconds). Retaining memory allows for faster reuse. The allowed values are `0`–`18446744073709551615`. The default value is `10000` (10 seconds). You can use a shorter delay to help avoid out-of-memory issues, at the expense of slower performance. This parameter applies to Aurora MySQL version 3.05 and higher. | | `aurora_jemalloc_tcache_enabled` | Yes | Use this parameter to serve small memory requests (up to 32 KiB) in a thread local cache, bypassing the memory arenas. The allowed values are `0` (disabled) and `1` (enabled). The default value is `1`. This parameter applies to Aurora MySQL version 3.05 and higher. | | `aurora_load_from_s3_role` | Yes | For more information, see [Loading data into an Amazon Aurora MySQL DB cluster from text files in an Amazon S3 bucket](AuroraMySQL.Integrating.LoadFromS3.md). Currently not available in Aurora MySQL version 3. Use `aws_default_s3_role`. | | `aurora_mask_password_hashes_type` | Yes | This setting is turned on by default in Aurora MySQL 2.11 and higher. Use this setting to mask Aurora MySQL password hashes in the slow query and audit logs. The allowed values are `0` and `1` (default). When set to `1`, passwords are logged as ``. When set to `0`, passwords are logged as hash (`#`) values. | | `aurora_select_into_s3_role` | Yes | For more information, see [Saving data from an Amazon Aurora MySQL DB cluster into text files in an Amazon S3 bucket](AuroraMySQL.Integrating.SaveIntoS3.md). Currently not available in Aurora MySQL version 3. Use `aws_default_s3_role`. | | `authentication_kerberos_caseins_cmp` | Yes | Controls case-insensitive username comparison for the `authentication_kerberos` plugin. Set it to `true` for case-insensitive comparison. By default, case-sensitive comparison is used (`false`). For more information, see [Using Kerberos authentication for Aurora MySQL](aurora-mysql-kerberos.md). This parameter is available in Aurora MySQL version 3.03 and higher. | | `auto_increment_increment` | Yes | None | | `auto_increment_offset` | Yes | None | | `aws_default_lambda_role` | Yes | For more information, see [Invoking a Lambda function from an Amazon Aurora MySQL DB cluster](AuroraMySQL.Integrating.Lambda.md). | | `aws_default_s3_role` | Yes | Used when invoking the `LOAD DATA FROM S3`, `LOAD XML FROM S3`, or `SELECT INTO OUTFILE S3` statement from your DB cluster. In Aurora MySQL version 2, the IAM role specified in this parameter is used if an IAM role isn't specified for `aurora_load_from_s3_role` or `aurora_select_into_s3_role` for the appropriate statement. In Aurora MySQL version 3, the IAM role specified for this parameter is always used. For more information, see [Associating an IAM role with an Amazon Aurora MySQL DB cluster](AuroraMySQL.Integrating.Authorizing.IAM.AddRoleToDBCluster.md). | | `binlog_backup` | Yes | Set the value of this parameter to 0 to turn on the enhanced binlog in Aurora MySQL version 3.03.1 and higher. You can turn off this parameter only when you use enhanced binlog. For more information, see [Setting up enhanced binlog for Aurora MySQL](AuroraMySQL.Enhanced.binlog.md). | | `binlog_checksum` | Yes | The AWS CLI and RDS API report a value of `None` if this parameter isn't set. In that case, Aurora MySQL uses the engine default value, which is `CRC32`. This is different from the explicit setting of `NONE`, which turns off the checksum. | | `binlog-do-db` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_format` | Yes | For more information, see [Replication between Aurora and MySQL or between Aurora and another Aurora DB cluster (binary log replication)](AuroraMySQL.Replication.MySQL.md). | | `binlog_group_commit_sync_delay` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_group_commit_sync_no_delay_count` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog-ignore-db` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_replication_globaldb` | Yes | Set the value of this parameter to 0 to turn on the enhanced binlog in Aurora MySQL version 3.03.1 and higher. You can turn off this parameter only when you use enhanced binlog. For more information, see [Setting up enhanced binlog for Aurora MySQL](AuroraMySQL.Enhanced.binlog.md). | | `binlog_row_image` | No | None | | `binlog_row_metadata` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_row_value_options` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_rows_query_log_events` | Yes | None | | `binlog_transaction_compression` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_transaction_compression_level_zstd` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_transaction_dependency_history_size` | Yes | This parameter sets an upper limit on the number of row hashes that are kept in memory and used for looking up the transaction that last modified a given row. After this number of hashes has been reached, the history is purged. This parameter applies to Aurora MySQL version 2.12 and higher, and version 3. | | `binlog_transaction_dependency_tracking` | Yes | This parameter applies to Aurora MySQL version 3. | | `character-set-client-handshake` | Yes | None | | `character_set_client` | Yes | None | | `character_set_connection` | Yes | None | | `character_set_database` | Yes | The character set used by the default database. The default value is `utf8mb4`. | | `character_set_filesystem` | Yes | None | | `character_set_results` | Yes | None | | `character_set_server` | Yes | None | | `collation_connection` | Yes | None | | `collation_server` | Yes | None | | `completion_type` | Yes | None | | `default_storage_engine` | No | Aurora MySQL clusters use the InnoDB storage engine for all of your data. | | `enforce_gtid_consistency` | Sometimes | Modifiable in Aurora MySQL version 2 and higher. | | `event_scheduler` | Yes | Indicates the status of the Event Scheduler. Modifiable only at the cluster level in Aurora MySQL version 3. | | `gtid-mode` | Sometimes | Modifiable in Aurora MySQL version 2 and higher. | | `information_schema_stats_expiry` | Yes | The number of seconds after which the MySQL database server fetches data from the storage engine and replaces the data in the cache. The allowed values are `0`–`31536000`. This parameter applies to Aurora MySQL version 3. | | `init_connect` | Yes | The command to be run by the server for each client that connects. Use double quotes (") for settings to avoid connection failures, for example: 
SET optimizer_switch="hash_join=off"
In Aurora MySQL version 3, this parameter doesn't apply for users who have the `CONNECTION_ADMIN` privilege. This includes the Aurora master user. For more information, see [Role-based privilege model](AuroraMySQL.Compare-80-v3.md#AuroraMySQL.privilege-model). | | `innodb_adaptive_hash_index` | Yes | You can modify this parameter at the DB cluster level in Aurora MySQL versions 2 and 3. The Adaptive Hash Index isn't supported on reader DB instances. | | `innodb_aurora_instant_alter_column_allowed` | Yes | Controls whether the `INSTANT` algorithm can be used for `ALTER COLUMN` operations at the global level. The allowed values are the following: [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Reference.ParameterGroups.html) For more information, see [Column Operations](https://dev.mysql.com/doc/refman/8.0/en/innodb-online-ddl-operations.html#online-ddl-column-operations) in the MySQL documentation. This parameter applies to Aurora MySQL version 3.05 and higher. | | `innodb_autoinc_lock_mode` | Yes | None | | `innodb_checksums` | No | Removed from Aurora MySQL version 3. | | `innodb_cmp_per_index_enabled` | Yes | None | | `innodb_commit_concurrency` | Yes | None | | `innodb_data_home_dir` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `innodb_deadlock_detect` | Yes | This option is used to disable deadlock detection in Aurora MySQL version 2.11 and higher and version 3. On high-concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. Consult the MySQL documentation for more information on this parameter. | | `innodb_default_row_format` | Yes | This parameter defines the default row format for InnoDB tables (including user-created InnoDB temporary tables). It applies to Aurora MySQL versions 2 and 3. Its value can be `DYNAMIC`, `COMPACT`, or `REDUNDANT.` | | `innodb_file_per_table` | Yes | This parameter affects how table storage is organized. For more information, see [Storage scaling](Aurora.Managing.Performance.md#Aurora.Managing.Performance.StorageScaling). | | `innodb_flush_log_at_trx_commit` | Yes | We highly recommend that you use the default value of `1`. In Aurora MySQL version 3, before you can set this parameter to a value other than `1`, you must set the value of `innodb_trx_commit_allow_data_loss` to `1`. For more information, see [Configuring how frequently the log buffer is flushed](AuroraMySQL.BestPractices.FeatureRecommendations.md#AuroraMySQL.BestPractices.Flush). | | `innodb_ft_max_token_size` | Yes | None | | `innodb_ft_min_token_size` | Yes | None | | `innodb_ft_num_word_optimize` | Yes | None | | `innodb_ft_sort_pll_degree` | Yes | None | | `innodb_online_alter_log_max_size` | Yes | None | | `innodb_optimize_fulltext_only` | Yes | None | | `innodb_page_size` | No | None | | `innodb_print_all_deadlocks` | Yes | When turned on, records information about all InnoDB deadlocks in the Aurora MySQL error log. For more information, see [Minimizing and troubleshooting Aurora MySQL deadlocks](AuroraMySQL.BestPractices.FeatureRecommendations.md#AuroraMySQL.BestPractices.deadlocks). | | `innodb_purge_batch_size` | Yes | None | | `innodb_purge_threads` | Yes | None | | `innodb_rollback_on_timeout` | Yes | None | | `innodb_rollback_segments` | Yes | None | | `innodb_spin_wait_delay` | Yes | None | | `innodb_strict_mode` | Yes | None | | `innodb_support_xa` | Yes | Removed from Aurora MySQL version 3. | | `innodb_sync_array_size` | Yes | None | | `innodb_sync_spin_loops` | Yes | None | | `innodb_stats_include_delete_marked` | Yes | When this parameter is enabled, InnoDB includes delete-marked records when calculating persistent optimizer statistics. This parameter applies to Aurora MySQL version 2.12 and higher, and version 3. | | `innodb_table_locks` | Yes | None | | `innodb_trx_commit_allow_data_loss` | Yes | In Aurora MySQL version 3, set the value of this parameter to `1` so that you can change the value of `innodb_flush_log_at_trx_commit`. The default value of `innodb_trx_commit_allow_data_loss` is `0`. For more information, see [Configuring how frequently the log buffer is flushed](AuroraMySQL.BestPractices.FeatureRecommendations.md#AuroraMySQL.BestPractices.Flush). | | `innodb_undo_directory` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `internal_tmp_disk_storage_engine` | Yes | Controls which in-memory storage engine is used for internal temporary tables. Allowed values are `INNODB` and `MYISAM`. This parameter applies to Aurora MySQL version 2. | | `internal_tmp_mem_storage_engine` | Yes | Controls which in-memory storage engine is used for internal temporary tables. Allowed values are `MEMORY` and `TempTable`. This parameter applies to Aurora MySQL version 3. | | `key_buffer_size` | Yes | Key cache for MyISAM tables. For more information, see [keycache->cache\$1lock mutex](AuroraMySQL.Reference.Waitevents.md#key-cache.cache-lock). | | `lc_time_names` | Yes | None | | `log_error_suppression_list` | Yes | Specifies a list of error codes that aren't logged in the MySQL error log. This allows you to ignore certain noncritical error conditions to help keep your error logs clean. For more information, see [log\$1error\$1suppression\$1list](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_log_error_suppression_list) in the MySQL documentation. This parameter applies to Aurora MySQL version 3.03 and higher. | | `low_priority_updates` | Yes | `INSERT`, `UPDATE`, `DELETE`, and `LOCK TABLE WRITE` operations wait until there's no pending `SELECT` operation. This parameter affects only storage engines that use only table-level locking (MyISAM, MEMORY, MERGE). This parameter applies to Aurora MySQL version 3. | | `lower_case_table_names` | Yes (Aurora MySQL version 2) Only at cluster creation time (Aurora MySQL version 3) | In Aurora MySQL version 2.10 and higher 2.x versions, make sure to reboot all reader instances after changing this setting and rebooting the writer instance. For details, see [Rebooting an Aurora cluster with read availability](aurora-mysql-survivable-replicas.md). In Aurora MySQL version 3, the value of this parameter is set permanently at the time the cluster is created. If you use a nondefault value for this option, set up your Aurora MySQL version 3 custom parameter group before upgrading, and specify the parameter group during the snapshot restore operation that creates the version 3 cluster. With an Aurora global database based on Aurora MySQL, you can't perform an in-place upgrade from Aurora MySQL version 2 to version 3 if the `lower_case_table_names` parameter is turned on. For more information on the methods that you can use, see [Major version upgrades](aurora-global-database-upgrade.md#aurora-global-database-upgrade.major). | | `master-info-repository` | Yes | Removed from Aurora MySQL version 3. | | `master_verify_checksum` | Yes | Aurora MySQL version 2. Use `source_verify_checksum` in Aurora MySQL version 3. | | `max_delayed_threads` | Yes | Sets the maximum number of threads to handle `INSERT DELAYED` statements. This parameter applies to Aurora MySQL version 3. | | `max_error_count` | Yes | The maximum number of error, warning, and note messages to be stored for display. This parameter applies to Aurora MySQL version 3. | | `max_execution_time` | Yes | The timeout for running `SELECT` statements, in milliseconds. The value can be from `0`–`18446744073709551615`. When set to `0`, there is no timeout. For more information, see [max\$1execution\$1time](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_max_execution_time) in the MySQL documentation. | | `min_examined_row_limit` | Yes | Use this parameter to prevent queries that examine fewer than the specified number of rows from being logged. | | `partial_revokes` | No | This parameter applies to Aurora MySQL version 3. | | `preload_buffer_size` | Yes | The size of the buffer that's allocated when preloading indexes. This parameter applies to Aurora MySQL version 3. | | `query_cache_type` | Yes | Removed from Aurora MySQL version 3. | | `read_only` | Yes | When this parameter is turned on, the server permits no updates except from those performed by replica threads. For Aurora MySQL version 2, valid values are the following: [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Reference.ParameterGroups.html) For Aurora MySQL version 3, valid values are the following: [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Reference.ParameterGroups.html) In Aurora MySQL version 3, this parameter doesn't apply for users who have the `CONNECTION_ADMIN` privilege. This includes the Aurora master user. For more information, see [Role-based privilege model](AuroraMySQL.Compare-80-v3.md#AuroraMySQL.privilege-model). | | `relay-log-space-limit` | Yes | This parameter applies to Aurora MySQL version 3. | | `replica_parallel_type` | Yes | This parameter enables parallel execution on the replica of all uncommitted threads already in the prepare phase, without violating consistency. It applies to Aurora MySQL version 3. In Aurora MySQL version 3.03.\$1 and lower, the default value is DATABASE. In Aurora MySQL version 3.04 and higher, the default value is LOGICAL\$1CLOCK. | | `replica_preserve_commit_order` | Yes | This parameter applies to Aurora MySQL version 3. | | `replica_transaction_retries` | Yes | This parameter applies to Aurora MySQL version 3. | | `replica_type_conversions` | Yes | This parameter determines the type conversions used on replicas. The allowed values are: `ALL_LOSSY`, `ALL_NON_LOSSY`, `ALL_SIGNED`, and `ALL_UNSIGNED`. For more information, see [Replication with differing table definitions on source and replica](https://dev.mysql.com/doc/refman/8.0/en/replication-features-differing-tables.html) in the MySQL documentation. This parameter applies to Aurora MySQL version 3. | | `replicate-do-db` | Yes | This parameter applies to Aurora MySQL version 3. | | `replicate-do-table` | Yes | This parameter applies to Aurora MySQL version 3. | | `replicate-ignore-db` | Yes | This parameter applies to Aurora MySQL version 3. | | `replicate-ignore-table` | Yes | This parameter applies to Aurora MySQL version 3. | | `replicate-wild-do-table` | Yes | This parameter applies to Aurora MySQL version 3. | | `replicate-wild-ignore-table` | Yes | This parameter applies to Aurora MySQL version 3. | | `require_secure_transport` | Yes | This parameter applies to Aurora MySQL version 2 and 3. For more information, see [TLS connections to Aurora MySQL DB clusters](AuroraMySQL.Security.md#AuroraMySQL.Security.SSL). | | `rpl_read_size` | Yes | This parameter applies to Aurora MySQL version 3. | | `server_audit_cw_upload` | No | This parameter has been deprecated in Aurora MySQL. Use `server_audit_logs_upload`. For more information, see [Publishing Amazon Aurora MySQL logs to Amazon CloudWatch Logs](AuroraMySQL.Integrating.CloudWatch.md). | | `server_audit_events` | Yes | For more information, see [Using Advanced Auditing with an Amazon Aurora MySQL DB cluster](AuroraMySQL.Auditing.md). | | `server_audit_excl_users` | Yes | For more information, see [Using Advanced Auditing with an Amazon Aurora MySQL DB cluster](AuroraMySQL.Auditing.md). | | `server_audit_incl_users` | Yes | For more information, see [Using Advanced Auditing with an Amazon Aurora MySQL DB cluster](AuroraMySQL.Auditing.md). | | `server_audit_logging` | Yes | For instructions on uploading the logs to Amazon CloudWatch Logs, see [Publishing Amazon Aurora MySQL logs to Amazon CloudWatch Logs](AuroraMySQL.Integrating.CloudWatch.md). | | `server_audit_logs_upload` | Yes | You can publish audit logs to CloudWatch Logs by enabling Advanced Auditing and setting this parameter to `1`. The default for the `server_audit_logs_upload` parameter is `0`. For more information, see [Publishing Amazon Aurora MySQL logs to Amazon CloudWatch Logs](AuroraMySQL.Integrating.CloudWatch.md). | | `server_id` | No | None | | `skip-character-set-client-handshake` | Yes | None | | `skip_name_resolve` | No | None | | `slave-skip-errors` | Yes | Only applies to Aurora MySQL version 2 clusters, with MySQL 5.7 compatibility. | | `source_verify_checksum` | Yes | This parameter applies to Aurora MySQL version 3. | | `sync_frm` | Yes | Removed from Aurora MySQL version 3. | | `thread_cache_size` | Yes | The number of threads to be cached. This parameter applies to Aurora MySQL versions 2 and 3. | | `time_zone` | Yes | By default, the time zone for an Aurora DB cluster is Universal Time Coordinated (UTC). You can set the time zone for instances in your DB cluster to the local time zone for your application instead. For more information, see [Local time zone for Amazon Aurora DB clusters](Concepts.RegionsAndAvailabilityZones.md#Aurora.Overview.LocalTimeZone). | | `tls_version` | Yes | For more information, see [TLS versions for Aurora MySQL](AuroraMySQL.Security.md#AuroraMySQL.Security.SSL.TLS_Version). | ## Instance-level parameters The following table shows all of the parameters that apply to a specific DB instance in an Aurora MySQL DB cluster. | Parameter name | Modifiable | Notes | | --- | --- | --- | | `activate_all_roles_on_login` | Yes | This parameter applies to Aurora MySQL version 3. | | `allow-suspicious-udfs` | No | None | | `aurora_disable_hash_join` | Yes | Set this parameter to `ON` to turn off hash join optimization in Aurora MySQL version 2.09 or higher. It isn't supported for version 3. For more information, see [Parallel query for Amazon Aurora MySQL](aurora-mysql-parallel-query.md). | | `aurora_lab_mode` | Yes | For more information, see [Amazon Aurora MySQL lab mode](AuroraMySQL.Updates.LabMode.md). Removed from Aurora MySQL version 3. | | `aurora_oom_response` | Yes | This parameter is supported for Aurora MySQL versions 2 and 3. For more information, see [Troubleshooting out-of-memory issues for Aurora MySQL databases](AuroraMySQLOOM.md). | | `aurora_parallel_query` | Yes | Set to `ON` to turn on parallel query in Aurora MySQL version 2.09 or higher. The old `aurora_pq` parameter isn't used in these versions. For more information, see [Parallel query for Amazon Aurora MySQL](aurora-mysql-parallel-query.md). | | `aurora_pq` | Yes | Set to `OFF` to turn off parallel query for specific DB instances in Aurora MySQL versions before 2.09. In version 2.09 or higher, turn parallel query on and off with `aurora_parallel_query` instead. For more information, see [Parallel query for Amazon Aurora MySQL](aurora-mysql-parallel-query.md). | | `aurora_read_replica_read_committed` | Yes | Enables `READ COMMITTED` isolation level for Aurora Replicas and changes the isolation behavior to reduce purge lag during long-running queries. Enable this setting only if you understand the behavior changes and how they affect your query results. For example, this setting uses less-strict isolation than the MySQL default. When it's enabled, long-running queries might see more than one copy of the same row because Aurora reorganizes the table data while the query is running. For more information, see [Aurora MySQL isolation levels](AuroraMySQL.Reference.IsolationLevels.md). | | `aurora_tmptable_enable_per_table_limit` | Yes | Determines whether the `tmp_table_size` parameter controls the maximum size of in-memory temporary tables created by the `TempTable` storage engine in Aurora MySQL version 3.04 and higher. For more information, see [Limiting the size of internal, in-memory temporary tables](ams3-temptable-behavior.md#ams3-temptable-behavior-limit). | | `aurora_use_vector_instructions` | Yes | When this parameter is enabled, Aurora MySQL uses optimized vector processing instructions provided by modern CPUs to improve performance on I/O-intensive workloads. This setting is enabled by default in Aurora MySQL version 3.05 and higher. | | `autocommit` | Yes | None | | `automatic_sp_privileges` | Yes | None | | `back_log` | Yes | None | | `basedir` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `binlog_cache_size` | Yes | None | | `binlog_max_flush_queue_time` | Yes | None | | `binlog_order_commits` | Yes | None | | `binlog_stmt_cache_size` | Yes | None | | `binlog_transaction_compression` | Yes | This parameter applies to Aurora MySQL version 3. | | `binlog_transaction_compression_level_zstd` | Yes | This parameter applies to Aurora MySQL version 3. | | `bulk_insert_buffer_size` | Yes | None | | `concurrent_insert` | Yes | None | | `connect_timeout` | Yes | None | | `core-file` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `datadir` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `default_authentication_plugin` | No | This parameter applies to Aurora MySQL version 3. | | `default_time_zone` | No | None | | `default_tmp_storage_engine` | Yes | The default storage engine for temporary tables. | | `default_week_format` | Yes | None | | `delay_key_write` | Yes | None | | `delayed_insert_limit` | Yes | None | | `delayed_insert_timeout` | Yes | None | | `delayed_queue_size` | Yes | None | | `div_precision_increment` | Yes | None | | `end_markers_in_json` | Yes | None | | `eq_range_index_dive_limit` | Yes | None | | `event_scheduler` | Sometimes | Indicates the status of the Event Scheduler. Modifiable only at the cluster level in Aurora MySQL version 3. | | `explicit_defaults_for_timestamp` | Yes | None | | `flush` | No | None | | `flush_time` | Yes | None | | `ft_boolean_syntax` | No | None | | `ft_max_word_len` | Yes | None | | `ft_min_word_len` | Yes | None | | `ft_query_expansion_limit` | Yes | None | | `ft_stopword_file` | Yes | None | | `general_log` | Yes | For instructions on uploading the logs to CloudWatch Logs, see [Publishing Amazon Aurora MySQL logs to Amazon CloudWatch Logs](AuroraMySQL.Integrating.CloudWatch.md). | | `general_log_file` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `group_concat_max_len` | Yes | None | | `host_cache_size` | Yes | None | | `init_connect` | Yes | The command to be run by the server for each client that connects. Use double quotes (") for settings to avoid connection failures, for example: 
SET optimizer_switch="hash_join=off"
In Aurora MySQL version 3, this parameter doesn't apply for users who have the `CONNECTION_ADMIN` privilege, including the Aurora master user. For more information, see [Role-based privilege model](AuroraMySQL.Compare-80-v3.md#AuroraMySQL.privilege-model). | | `innodb_adaptive_hash_index` | Yes | You can modify this parameter at the DB instance level in Aurora MySQL version 2. It's modifiable only at the DB cluster level in Aurora MySQL version 3. The Adaptive Hash Index isn't supported on reader DB instances. | | `innodb_adaptive_max_sleep_delay` | Yes | Modifying this parameter has no effect because `innodb_thread_concurrency` is always 0 for Aurora. | | `innodb_aurora_max_partitions_for_range` | Yes | In some cases where persisted statistics aren't available, you can use this parameter to improve the performance of row count estimations on partitioned tables. You can set it to a value from 0–8192, where the value determines the number of partitions to check during row count estimation. The default value is 0, which estimates using all of the partitions, consistent with default MySQL behavior. This parameter is available for Aurora MySQL version 3.03.1 and higher. | | `innodb_autoextend_increment` | Yes | None | | `innodb_buffer_pool_dump_at_shutdown` | No | None | | `innodb_buffer_pool_dump_now` | No | None | | `innodb_buffer_pool_filename` | No | None | | `innodb_buffer_pool_load_abort` | No | None | | `innodb_buffer_pool_load_at_startup` | No | None | | `innodb_buffer_pool_load_now` | No | None | | `innodb_buffer_pool_size` | Yes | The default value is represented by a formula. For details about how the `DBInstanceClassMemory` value in the formula is calculated, see [DB parameter formula variables](USER_ParamValuesRef.md#USER_FormulaVariables). | | `innodb_change_buffer_max_size` | No | Aurora MySQL doesn't use the InnoDB change buffer at all. | | `innodb_compression_failure_threshold_pct` | Yes | None | | `innodb_compression_level` | Yes | None | | `innodb_compression_pad_pct_max` | Yes | None | | `innodb_concurrency_tickets` | Yes | Modifying this parameter has no effect, because `innodb_thread_concurrency` is always 0 for Aurora. | | `innodb_deadlock_detect` | Yes | This option is used to disable deadlock detection in Aurora MySQL version 2.11 and higher and version 3. On high-concurrency systems, deadlock detection can cause a slowdown when numerous threads wait for the same lock. Consult the MySQL documentation for more information on this parameter. | | `innodb_file_format` | Yes | Removed from Aurora MySQL version 3. | | `innodb_flushing_avg_loops` | No | None | | `innodb_force_load_corrupted` | No | None | | `innodb_ft_aux_table` | Yes | None | | `innodb_ft_cache_size` | Yes | None | | `innodb_ft_enable_stopword` | Yes | None | | `innodb_ft_server_stopword_table` | Yes | None | | `innodb_ft_user_stopword_table` | Yes | None | | `innodb_large_prefix` | Yes | Removed from Aurora MySQL version 3. | | `innodb_lock_wait_timeout` | Yes | None | | `innodb_log_compressed_pages` | No | None | | `innodb_lru_scan_depth` | Yes | None | | `innodb_max_purge_lag` | Yes | None | | `innodb_max_purge_lag_delay` | Yes | None | | `innodb_monitor_disable` | Yes | None | | `innodb_monitor_enable` | Yes | None | | `innodb_monitor_reset` | Yes | None | | `innodb_monitor_reset_all` | Yes | None | | `innodb_old_blocks_pct` | Yes | None | | `innodb_old_blocks_time` | Yes | None | | `innodb_open_files` | Yes | None | | `innodb_print_all_deadlocks` | Yes | When turned on, records information about all InnoDB deadlocks in the Aurora MySQL error log. For more information, see [Minimizing and troubleshooting Aurora MySQL deadlocks](AuroraMySQL.BestPractices.FeatureRecommendations.md#AuroraMySQL.BestPractices.deadlocks). | | `innodb_random_read_ahead` | Yes | None | | `innodb_read_ahead_threshold` | Yes | None | | `innodb_read_io_threads` | No | None | | `innodb_read_only` | No | Aurora MySQL manages the read-only and read/write state of DB instances based on the type of cluster. For example, a provisioned cluster has one read/write DB instance (the *primary instance*) and any other instances in the cluster are read-only (the Aurora Replicas). | | `innodb_replication_delay` | Yes | None | | `innodb_sort_buffer_size` | Yes | None | | `innodb_stats_auto_recalc` | Yes | None | | `innodb_stats_method` | Yes | None | | `innodb_stats_on_metadata` | Yes | None | | `innodb_stats_persistent` | Yes | None | | `innodb_stats_persistent_sample_pages` | Yes | None | | `innodb_stats_transient_sample_pages` | Yes | None | | `innodb_thread_concurrency` | No | None | | `innodb_thread_sleep_delay` | Yes | Modifying this parameter has no effect because `innodb_thread_concurrency` is always 0 for Aurora. | | `interactive_timeout` | Yes | Aurora evaluates the minimum value of `interactive_timeout` and `wait_timeout`. It then uses that minimum as the timeout to end all idle sessions, both interactive and noninteractive. | | `internal_tmp_disk_storage_engine` | Yes | Controls which in-memory storage engine is used for internal temporary tables. Allowed values are `INNODB` and `MYISAM`. This parameter applies to Aurora MySQL version 2. | | `internal_tmp_mem_storage_engine` | Sometimes | Controls which in-memory storage engine is used for internal temporary tables. Allowed values for writer DB instances are `MEMORY` and `TempTable`. For reader DB instances, this parameter is set to `TempTable` and can't be modified. This parameter applies to Aurora MySQL version 3. | | `join_buffer_size` | Yes | None | | `keep_files_on_create` | Yes | None | | `key_buffer_size` | Yes | Key cache for MyISAM tables. For more information, see [keycache->cache\$1lock mutex](AuroraMySQL.Reference.Waitevents.md#key-cache.cache-lock). | | `key_cache_age_threshold` | Yes | None | | `key_cache_block_size` | Yes | None | | `key_cache_division_limit` | Yes | None | | `local_infile` | Yes | None | | `lock_wait_timeout` | Yes | None | | `log-bin` | No | Setting `binlog_format` to `STATEMENT`, `MIXED`, or `ROW` automatically sets `log-bin` to `ON`. Setting `binlog_format` to `OFF` automatically sets `log-bin` to `OFF`. For more information, see [Replication between Aurora and MySQL or between Aurora and another Aurora DB cluster (binary log replication)](AuroraMySQL.Replication.MySQL.md). | | `log_bin_trust_function_creators` | Yes | None | | `log_bin_use_v1_row_events` | Yes | Removed from Aurora MySQL version 3. | | `log_error` | No | None | | `log_error_suppression_list` | Yes | Specifies a list of error codes that aren't logged in the MySQL error log. This allows you to ignore certain noncritical error conditions to help keep your error logs clean. For more information, see [log\$1error\$1suppression\$1list](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_log_error_suppression_list) in the MySQL documentation. This parameter applies to Aurora MySQL version 3.03 and higher. | | `log_output` | Yes | None | | `log_queries_not_using_indexes` | Yes | None | | `log_slave_updates` | No | Aurora MySQL version 2. Use `log_replica_updates` in Aurora MySQL version 3. | | `log_replica_updates` | No | Aurora MySQL version 3 | | `log_throttle_queries_not_using_indexes` | Yes | None | | `log_warnings` | Yes | Removed from Aurora MySQL version 3. | | `long_query_time` | Yes | None | | `low_priority_updates` | Yes | `INSERT`, `UPDATE`, `DELETE`, and `LOCK TABLE WRITE` operations wait until there's no pending `SELECT` operation. This parameter affects only storage engines that use only table-level locking (MyISAM, MEMORY, MERGE). This parameter applies to Aurora MySQL version 3. | | `max_allowed_packet` | Yes | None | | `max_binlog_cache_size` | Yes | None | | `max_binlog_size` | No | None | | `max_binlog_stmt_cache_size` | Yes | None | | `max_connect_errors` | Yes | None | | `max_connections` | Yes | The default value is represented by a formula. For details about how the `DBInstanceClassMemory` value in the formula is calculated, see [DB parameter formula variables](USER_ParamValuesRef.md#USER_FormulaVariables). For the default values depending on the instance class, see [Maximum connections to an Aurora MySQL DB instance](AuroraMySQL.Managing.Performance.md#AuroraMySQL.Managing.MaxConnections). | | `max_delayed_threads` | Yes | Sets the maximum number of threads to handle `INSERT DELAYED` statements. This parameter applies to Aurora MySQL version 3. | | `max_error_count` | Yes | The maximum number of error, warning, and note messages to be stored for display. This parameter applies to Aurora MySQL version 3. | | `max_execution_time` | Yes | The timeout for running `SELECT` statements, in milliseconds. The value can be from `0`–`18446744073709551615`. When set to `0`, there is no timeout. For more information, see [max\$1execution\$1time](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_max_execution_time) in the MySQL documentation. | | `max_heap_table_size` | Yes | None | | `max_insert_delayed_threads` | Yes | None | | `max_join_size` | Yes | None | | `max_length_for_sort_data` | Yes | Removed from Aurora MySQL version 3. | | `max_prepared_stmt_count` | Yes | None | | `max_seeks_for_key` | Yes | None | | `max_sort_length` | Yes | None | | `max_sp_recursion_depth` | Yes | None | | `max_tmp_tables` | Yes | Removed from Aurora MySQL version 3. | | `max_user_connections` | Yes | None | | `max_write_lock_count` | Yes | None | | `metadata_locks_cache_size` | Yes | Removed from Aurora MySQL version 3. | | `min_examined_row_limit` | Yes | Use this parameter to prevent queries that examine fewer than the specified number of rows from being logged. This parameter applies to Aurora MySQL version 3. | | `myisam_data_pointer_size` | Yes | None | | `myisam_max_sort_file_size` | Yes | None | | `myisam_mmap_size` | Yes | None | | `myisam_sort_buffer_size` | Yes | None | | `myisam_stats_method` | Yes | None | | `myisam_use_mmap` | Yes | None | | `net_buffer_length` | Yes | None | | `net_read_timeout` | Yes | None | | `net_retry_count` | Yes | None | | `net_write_timeout` | Yes | None | | `old-style-user-limits` | Yes | None | | `old_passwords` | Yes | Removed from Aurora MySQL version 3. | | `optimizer_prune_level` | Yes | None | | `optimizer_search_depth` | Yes | None | | `optimizer_switch` | Yes | For information about Aurora MySQL features that use this switch, see [Best practices with Amazon Aurora MySQL](AuroraMySQL.BestPractices.md). | | `optimizer_trace` | Yes | None | | `optimizer_trace_features` | Yes | None | | `optimizer_trace_limit` | Yes | None | | `optimizer_trace_max_mem_size` | Yes | None | | `optimizer_trace_offset` | Yes | None | | `performance-schema-consumer-events-waits-current` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance-schema-consumer-events-waits-current`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance-schema-instrument` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance-schema-instrument`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema` | Yes | If the **Source** column is set to `Modified`, Performance Insights is managing the Performance Schema. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_accounts_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_accounts_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_global_instrumentation` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_global_instrumentation`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_thread_instrumentation` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_thread_instrumentation`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_stages_current` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_stages_current`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_stages_history` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_stages_history`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_stages_history_long` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_stages_history_long`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_statements_current` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_statements_current`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_statements_history` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_statements_history`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_statements_history_long` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_statements_history_long`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_waits_history` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_waits_history`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_events_waits_history_long` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_events_waits_history_long`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_consumer_statements_digest` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_consumer_statements_digest`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_digests_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_digests_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_stages_history_long_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_stages_history_long_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_stages_history_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_stages_history_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_statements_history_long_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_statements_history_long_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_statements_history_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_statements_history_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_transactions_history_long_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_transactions_history_long_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_transactions_history_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_transactions_history_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_waits_history_long_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_waits_history_long_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_events_waits_history_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_events_waits_history_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_hosts_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_hosts_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_cond_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_cond_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_cond_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_cond_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_digest_length` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_digest_length`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_file_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_file_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_file_handles` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_file_handles`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_file_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_file_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_index_stat` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_index_stat`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_memory_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_memory_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_metadata_locks` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_metadata_locks`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_mutex_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_mutex_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_mutex_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_mutex_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_prepared_statements_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_prepared_statements_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_program_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_program_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_rwlock_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_rwlock_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_rwlock_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_rwlock_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_socket_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_socket_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_socket_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_socket_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_sql_text_length` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_sql_text_length`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_stage_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_stage_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_statement_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_statement_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_statement_stack` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_statement_stack`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_table_handles` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_table_handles`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_table_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_table_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_table_lock_stat` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_table_lock_stat`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_thread_classes` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_thread_classes`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_max_thread_instances` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_max_thread_instances`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_session_connect_attrs_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_session_connect_attrs_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_setup_actors_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_setup_actors_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_setup_objects_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_setup_objects_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_show_processlist` | Yes | This parameter determines which SHOW PROCESSLIST implementation to use: [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Reference.ParameterGroups.html)This parameter applies to Aurora MySQL version 2.12 and higher, and version 3. If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_show_processlist`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `performance_schema_users_size` | Yes | If the **Source** column for the parameter `performance_schema` is set to `Modified`, performance schema is using the parameter `performance_schema_users_size`. For more information about enabling the Performance Schema, see [Determining whether Performance Insights is managing the Performance Schema](USER_PerfInsights.EnableMySQL.determining-status.md). | | `pid_file` | No | None | | `plugin_dir` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `port` | No | Aurora MySQL manages the connection properties and enforces consistent settings for all DB instances in a cluster. | | `preload_buffer_size` | Yes | The size of the buffer that's allocated when preloading indexes. This parameter applies to Aurora MySQL version 3. | | `profiling_history_size` | Yes | None | | `query_alloc_block_size` | Yes | None | | `query_cache_limit` | Yes | Removed from Aurora MySQL version 3. | | `query_cache_min_res_unit` | Yes | Removed from Aurora MySQL version 3. | | `query_cache_size` | Yes | The default value is represented by a formula. For details about how the `DBInstanceClassMemory` value in the formula is calculated, see [DB parameter formula variables](USER_ParamValuesRef.md#USER_FormulaVariables). Removed from Aurora MySQL version 3. | | `query_cache_type` | Yes | Removed from Aurora MySQL version 3. | | `query_cache_wlock_invalidate` | Yes | Removed from Aurora MySQL version 3. | | `query_prealloc_size` | Yes | None | | `range_alloc_block_size` | Yes | None | | `read_buffer_size` | Yes | None | | `read_only` | Yes | When this parameter is turned on, the server permits no updates except from those performed by replica threads. For Aurora MySQL version 2, valid values are the following: [\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Reference.ParameterGroups.html) We recommend that you use the DB cluster parameter group in Aurora MySQL version 2 to make sure that the `read_only` parameter is applied to new writer instances on failover. Reader instances are always read only, because Aurora MySQL sets `innodb_read_only` to `1` on all readers. Therefore, `read_only` is redundant on reader instances. Removed at the instance level from Aurora MySQL version 3. | | `read_rnd_buffer_size` | Yes | None | | `relay-log` | No | None | | `relay_log_info_repository` | Yes | Removed from Aurora MySQL version 3. | | `relay_log_recovery` | No | None | | `replica_checkpoint_group` | Yes | Aurora MySQL version 3 | | `replica_checkpoint_period` | Yes | Aurora MySQL version 3 | | `replica_parallel_workers` | Yes | Aurora MySQL version 3 | | `replica_pending_jobs_size_max` | Yes | Aurora MySQL version 3 | | `replica_skip_errors` | Yes | Aurora MySQL version 3 | | `replica_sql_verify_checksum` | Yes | Aurora MySQL version 3 | | `safe-user-create` | Yes | None | | `secure_auth` | Yes | This parameter is always turned on in Aurora MySQL version 2. Trying to turn it off generates an error. Removed from Aurora MySQL version 3. | | `secure_file_priv` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `show_create_table_verbosity` | Yes | Enabling this variable causes [SHOW\$1CREATE\$1TABLE](https://dev.mysql.com/doc/refman/5.7/en/show-create-table.html) to display the `ROW_FORMAT` regardless of whether it's the default format. This parameter applies to Aurora MySQL version 2.12 and higher, and version 3. | | `skip-slave-start` | No | None | | `skip_external_locking` | No | None | | `skip_show_database` | Yes | None | | `slave_checkpoint_group` | Yes | Aurora MySQL version 2. Use `replica_checkpoint_group` in Aurora MySQL version 3. | | `slave_checkpoint_period` | Yes | Aurora MySQL version 2. Use `replica_checkpoint_period` in Aurora MySQL version 3. | | `slave_parallel_workers` | Yes | Aurora MySQL version 2. Use `replica_parallel_workers` in Aurora MySQL version 3. | | `slave_pending_jobs_size_max` | Yes | Aurora MySQL version 2. Use `replica_pending_jobs_size_max` in Aurora MySQL version 3. | | `slave_sql_verify_checksum` | Yes | Aurora MySQL version 2. Use `replica_sql_verify_checksum` in Aurora MySQL version 3. | | `slow_launch_time` | Yes | None | | `slow_query_log` | Yes | For instructions on uploading the logs to CloudWatch Logs, see [Publishing Amazon Aurora MySQL logs to Amazon CloudWatch Logs](AuroraMySQL.Integrating.CloudWatch.md). | | `slow_query_log_file` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `socket` | No | None | | `sort_buffer_size` | Yes | None | | `sql_mode` | Yes | None | | `sql_select_limit` | Yes | None | | `stored_program_cache` | Yes | None | | `sync_binlog` | No | None | | `sync_master_info` | Yes | None | | `sync_source_info` | Yes | This parameter applies to Aurora MySQL version 3. | | `sync_relay_log` | Yes | Removed from Aurora MySQL version 3. | | `sync_relay_log_info` | Yes | None | | `sysdate-is-now` | Yes | None | | `table_cache_element_entry_ttl` | No | None | | `table_definition_cache` | Yes | The default value is represented by a formula. For details about how the `DBInstanceClassMemory` value in the formula is calculated, see [DB parameter formula variables](USER_ParamValuesRef.md#USER_FormulaVariables). | | `table_open_cache` | Yes | The default value is represented by a formula. For details about how the `DBInstanceClassMemory` value in the formula is calculated, see [DB parameter formula variables](USER_ParamValuesRef.md#USER_FormulaVariables). | | `table_open_cache_instances` | Yes | None | | `temp-pool` | Yes | Removed from Aurora MySQL version 3. | | `temptable_max_mmap` | Yes | This parameter applies to Aurora MySQL version 3. For details, see [New temporary table behavior in Aurora MySQL version 3](ams3-temptable-behavior.md). | | `temptable_max_ram` | Yes | This parameter applies to Aurora MySQL version 3. For details, see [New temporary table behavior in Aurora MySQL version 3](ams3-temptable-behavior.md). | | `temptable_use_mmap` | Yes | This parameter applies to Aurora MySQL version 3. For details, see [New temporary table behavior in Aurora MySQL version 3](ams3-temptable-behavior.md). | | `thread_cache_size` | Yes | The number of threads to be cached. This parameter applies to Aurora MySQL versions 2 and 3. | | `thread_handling` | No | None | | `thread_stack` | Yes | None | | `timed_mutexes` | Yes | None | | `tmp_table_size` | Yes | Defines the maximum size of internal in-memory temporary tables created by the `MEMORY` storage engine in Aurora MySQL version 3. In Aurora MySQL version 3.04 and higher, defines the maximum size of internal in-memory temporary tables created by the `TempTable` storage engine when `aurora_tmptable_enable_per_table_limit` is `ON`. For more information, see [Limiting the size of internal, in-memory temporary tables](ams3-temptable-behavior.md#ams3-temptable-behavior-limit). | | `tmpdir` | No | Aurora MySQL uses managed instances where you don't access the file system directly. | | `transaction_alloc_block_size` | Yes | None | | `transaction_isolation` | Yes | This parameter applies to Aurora MySQL version 3. It replaces `tx_isolation`. | | `transaction_prealloc_size` | Yes | None | | `tx_isolation` | Yes | Removed from Aurora MySQL version 3. It is replaced by `transaction_isolation`. | | `updatable_views_with_limit` | Yes | None | | `validate-password` | No | None | | `validate_password_dictionary_file` | No | None | | `validate_password_length` | No | None | | `validate_password_mixed_case_count` | No | None | | `validate_password_number_count` | No | None | | `validate_password_policy` | No | None | | `validate_password_special_char_count` | No | None | | `wait_timeout` | Yes | Aurora evaluates the minimum value of `interactive_timeout` and `wait_timeout`. It then uses that minimum as the timeout to end all idle sessions, both interactive and noninteractive. | ## MySQL parameters that don't apply to Aurora MySQL Because of architectural differences between Aurora MySQL and MySQL, some MySQL parameters don't apply to Aurora MySQL. The following MySQL parameters don't apply to Aurora MySQL. This list isn't exhaustive. + `activate_all_roles_on_login` – This parameter doesn't apply to Aurora MySQL version 2. It is available in Aurora MySQL version 3. + `big_tables` + `bind_address` + `character_sets_dir` + `innodb_adaptive_flushing` + `innodb_adaptive_flushing_lwm` + `innodb_buffer_pool_chunk_size` + `innodb_buffer_pool_instances` + `innodb_change_buffering` + `innodb_checksum_algorithm` + `innodb_data_file_path` + `innodb_dedicated_server` + `innodb_doublewrite` + `innodb_flush_log_at_timeout` – This parameter doesn't apply to Aurora MySQL. For more information, see [Configuring how frequently the log buffer is flushed](AuroraMySQL.BestPractices.FeatureRecommendations.md#AuroraMySQL.BestPractices.Flush). + `innodb_flush_method` + `innodb_flush_neighbors` + `innodb_io_capacity` + `innodb_io_capacity_max` + `innodb_log_buffer_size` + `innodb_log_file_size` + `innodb_log_files_in_group` + `innodb_log_spin_cpu_abs_lwm` + `innodb_log_spin_cpu_pct_hwm` + `innodb_log_writer_threads` + `innodb_max_dirty_pages_pct` + `innodb_numa_interleave` + `innodb_page_size` + `innodb_redo_log_capacity` + `innodb_redo_log_encrypt` + `innodb_undo_log_encrypt` + `innodb_undo_log_truncate` + `innodb_undo_logs` + `innodb_undo_tablespaces` + `innodb_use_native_aio` + `innodb_write_io_threads`