MySQL - Advanced parameters references

Last updated 6th February 2023

Objective

This guide lists all the supported advanced parameters that allow you to configure your Public Cloud Databases for MySQL according to your use cases.

Requirements

Instructions

The management of advanced parameters is not supported via Terraform.

Using the OVHcloud Control Panel

Please refer to this guide to find out how to change your advanced parameters from the OVHcloud Control Panel.

Using API

Please refer to this guide to find out how to change your advanced parameters from the OVHcloud API.

Advanced parameters for MySQL

Below you can find a summary of every configuration option available for MySQL service:

Parameter mysql.connect_timeout
Value type long
Minumum 2
Maximum 3600
Values
Description The number of seconds that the mysqld server waits for a connect packet before responding with Bad handshake
Parameter mysql.default_time_zone
Value type string
Minumum
Maximum
Values
Description Default server time zone as an offset from UTC (from -12:00 to +12:00), a time zone name, or 'SYSTEM' to use the MySQL server default.
Parameter mysql.group_concat_max_len
Value type long
Minumum 4
Maximum 18446744073709552000
Values
Description The maximum permitted result length in bytes for the GROUP_CONCAT() function.
Parameter mysql.information_schema_stats_expiry
Value type long
Minumum 900
Maximum 31536000
Values
Description The time, in seconds, before cached statistics expire
Parameter mysql.innodb_change_buffer_max_size
Value type long
Minumum 0
Maximum 50
Values
Description Maximum size for the InnoDB change buffer, as a percentage of the total size of the buffer pool. Default is 25
Parameter mysql.innodb_flush_neighbors
Value type long
Minumum 0
Maximum 2
Values
Description Specifies whether flushing a page from the InnoDB buffer pool also flushes other dirty pages in the same extent (default is 1): 0 - dirty pages in the same extent are not flushed, 1 - flush contiguous dirty pages in the same extent, 2 - flush dirty pages in the same extent
Parameter mysql.innodb_ft_min_token_size
Value type long
Minumum 0
Maximum 16
Values
Description Minimum length of words that are stored in an InnoDB FULLTEXT index. Changing this parameter will lead to a restart of the MySQL service.
Parameter mysql.innodb_lock_wait_timeout
Value type long
Minumum 1
Maximum 3600
Values
Description The length of time in seconds an InnoDB transaction waits for a row lock before giving up.
Parameter mysql.innodb_log_buffer_size
Value type long
Minumum 1048576
Maximum 4294967295
Values
Description The size in bytes of the buffer that InnoDB uses to write to the log files on disk.
Parameter mysql.innodb_online_alter_log_max_size
Value type long
Minumum 65536
Maximum 1099511627776
Values
Description The upper limit in bytes on the size of the temporary log files used during online DDL operations for InnoDB tables.
Parameter mysql.innodb_print_all_deadlocks
Value type boolean
Minumum
Maximum
Values
Description When enabled, information about all deadlocks in InnoDB user transactions is recorded in the error log. Disabled by default.
Parameter mysql.innodb_read_io_threads
Value type long
Minumum 1
Maximum 64
Values
Description The number of I/O threads for read operations in InnoDB. Default is 4. Changing this parameter will lead to a restart of the MySQL service.
Parameter mysql.innodb_rollback_on_timeout
Value type boolean
Minumum
Maximum
Values
Description When enabled a transaction timeout causes InnoDB to abort and roll back the entire transaction. Changing this parameter will lead to a restart of the MySQL service.
Parameter mysql.innodb_thread_concurrency
Value type long
Minumum 0
Maximum 1000
Values
Description Defines the maximum number of threads permitted inside of InnoDB. Default is 0 (infinite concurrency - no limit)
Parameter mysql.innodb_write_io_threads
Value type long
Minumum 1
Maximum 64
Values
Description The number of I/O threads for write operations in InnoDB. Default is 4. Changing this parameter will lead to a restart of the MySQL service.
Parameter mysql.interactive_timeout
Value type long
Minumum 30
Maximum 604800
Values
Description The number of seconds the server waits for activity on an interactive connection before closing it.
Parameter mysql.internal_tmp_mem_storage_engine
Value type string
Minumum
Maximum
Values "MEMORY", "TempTable"
Description The storage engine for in-memory internal temporary tables.
Parameter mysql.long_query_time
Value type double
Minumum 0
Maximum 3600
Values
Description The slow_query_logs work as SQL statements that take more than long_query_time seconds to execute. Default is 10s
Parameter mysql.max_allowed_packet
Value type long
Minumum 102400
Maximum 1073741824
Values
Description Size of the largest message in bytes that can be received by the server. Default is 67108864 (64M)
Parameter mysql.max_heap_table_size
Value type long
Minumum 1048576
Maximum 1073741824
Values
Description Limits the size of internal in-memory tables. Also set tmp_table_size. Default is 16777216 (16M)
Parameter mysql.net_buffer_length
Value type long
Minumum 1024
Maximum 1048576
Values
Description Start sizes of connection buffer and result buffer. Default is 16384 (16K). Changing this parameter will lead to a restart of the MySQL service.
Parameter mysql.net_read_timeout
Value type long
Minumum 1
Maximum 3600
Values
Description The number of seconds to wait for more data from a connection before aborting the read.
Parameter mysql.net_write_timeout
Value type long
Minumum 1
Maximum 3600
Values
Description The number of seconds to wait for a block to be written to a connection before aborting the write.
Parameter mysql.slow_query_log
Value type boolean
Minumum
Maximum
Values
Description Slow query log enables capturing of slow queries. Setting slow_query_log to false also truncates the mysql.slow_log table. Default is off
Parameter mysql.sort_buffer_size
Value type long
Minumum 32768
Maximum 1073741824
Values
Description Sort buffer size in bytes for ORDER BY optimization. Default is 262144 (256K)
Parameter mysql.sql_mode
Value type string
Minumum
Maximum
Values
Description Global SQL mode. Set to empty to use MySQL server defaults. When creating a new service and not setting this field Aiven default SQL mode (strict, SQL standard compliant) will be assigned.
Parameter mysql.sql_require_primary_key
Value type boolean
Minumum
Maximum
Values
Description Require primary key to be defined for new tables or old tables modified with ALTER TABLE and fail if missing. It is recommended to always have primary keys because various functionalities may break if any large table is missing them.
Parameter mysql.tmp_table_size
Value type long
Minumum 1048576
Maximum 1073741824
Values
Description Limits the size of internal in-memory tables. Also set max_heap_table_size. Default is 16777216 (16M)
Parameter mysql.wait_timeout
Value type long
Minumum 1
Maximum 2147483
Values
Description The number of seconds the server waits for activity on a non-interactive connection before closing it.

Go further

Visit our dedicated Discord channel: https://discord.gg/ovhcloud. Ask questions, provide feedback and interact directly with the team that builds our databases services.

Join our community of users on https://community.ovh.com/en/.


Did you find this guide useful?

Please feel free to give any suggestions in order to improve this documentation.

Whether your feedback is about images, content, or structure, please share it, so that we can improve it together.

Your support requests will not be processed via this form. To do this, please use the "Create a ticket" form.

Thank you. Your feedback has been received.


These guides might also interest you...

OVHcloud Community

Access your community space. Ask questions, search for information, post content, and interact with other OVHcloud Community members.

Discuss with the OVHcloud community