---
title: "MySQL semi-sync settings"
sidebar_label: "Settings"
sidebar_position: 5
description: "How to change MySQL semi-sync settings"
---

import Formbricks from '@theme/MDXComponents/Formbricks'
import Settings from '@site/i18n/en/docusaurus-plugin-content-docs/current/_partials/managed-databases/mysql/settings.mdx'
import CharsetAndCollation from '@site/i18n/en/docusaurus-plugin-content-docs/current/_partials/managed-databases/mysql/charset-and-collation.mdx'

# MySQL semi-sync settings

<Settings DatabaseName="MySQL semi-sync" slug="mysql-semi-sync" />

### List of settings that require a restart \{#list-of-settings-that-require-reboot}

* `default_time_zone;`
* `innodb_adaptive_hash_index_parts;`
* `innodb_autoinc_lock_mode;`
* `innodb_buffer_pool_instances;`
* `innodb_buffer_pool_load_at_startup;`
* `innodb_commit_concurrency;`
* `innodb_flush_method;`
* `innodb_ft_cache_size;`
* `innodb_ft_max_token_size;`
* `innodb_ft_min_token_size;`
* `innodb_ft_total_cache_size;`
* `innodb_ft_sort_pll_degree;`
* `innodb_log_buffer_size` (for MySQL semi-sync 5.7 only);
* `innodb_log_file_size` (for MySQL semi-sync 5.7 only);
* `innodb_page_cleaners;`
* `innodb_purge_threads;`
* `innodb_read_io_threads;`
* `innodb_rollback_on_timeout;`
* `innodb_sort_buffer_size;`
* `innodb_sync_array_size;`
* `innodb_write_io_threads;`
* `max_digest_length;`
* `table_open_cache_instances;`
* `thread_pool_size;`
* `thread_stack.`

## Automatic setting changes when scaling a cluster \{#automatically-changed-settings-after-scaling-up-cluster}

DBMS settings have valid range boundaries. If during [cluster scaling](/managed-databases/mysql-semi-sync/resize-cluster.mdx) setting values exceed the valid range, these values are automatically replaced with default values so that the cluster can continue to function.

After the cluster has been scaled and its status becomes `ACTIVE`, you will be able to [change settings](#change-settings) and set new values.

List of settings that are reset to their default values when scaling a cluster:

* `innodb_buffer_pool_instances;`
* `innodb_buffer_pool_size;`
* `innodb_log_file_size` (for MySQL semi-sync 5.7 only);
* `innodb_redo_log_capacity;`
* `max_connections;`
* `max_heap_table_size;`
* `temptable_max_ram;`
* `thread_pool_size;`
* `tmp_table_size.`

<CharsetAndCollation DatabaseName="MySQL semi-sync" slug="mysql-semi-sync" />

<Formbricks />