RDS for MySQL
RDS for MySQL
RDS for MySQL
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API reference
V2（2022-01-01）
Global management
Managing instances
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- Documentation
RDS for MySQLKernel functionsPerformanceHotcache
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Hotcache
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This topic describes the hotcache feature of RDS for MySQL.
Background
When MySQL restarts due to an upgrade or failure, the data cache in its BufferPool is cleared. This action prevents service requests from hitting the cache, which results in frequent disk I/O operations and significantly degrades the SQL performance of the database. To address this issue, RDS for MySQL places the BufferPool memory in shared memory. After a restart, it directly reuses the original memory, reducing service fluctuations in these scenarios.
Parameter description
Parameter name | Default value | Does it need instance restart to take effect? | Value range | Scope | Parameter description |
loose_buffer_pool_enable_hot_cache | off | Yes | [on|off] | Global | Enables or disables the hotcache feature. |
tip
This parameter is not open for modification. To modify it, submit a ticket to contact technical support.
Supported version
- MySQL 5.7 version, and the kernel minor version is MySQL 5.7.32_20241015 and above.
- MySQL 8.0, with a kernel minor version of MySQL 8.0.32_20241015 or later.
- MySQL 8.4, with a kernel minor version of MySQL 8.4.7_20260415 or later.
tip
You can view the kernel minor version of an instance by Viewing instance information. If your instance is a version earlier than MySQL 5.7.32_20241015 or MySQL 8.0.32_20241015, you can Upgrade instance kernel minor version.
Prerequisites
- An instance has been created and the state of the instance is Running.
- The running Value of the loose_buffer_pool_enable_hot_cache Parameter is set to on.
Status description
RDS for MySQL provides the following parameter to display the current state of hotcache:
Parameter name | Scope | Description |
Innodb_buffer_hot_cache_state | Global | State of Hotcache reuse:
|
Innodb_buffer_hot_cache_state_code | Global | Hotcache reuse status code:
|
Innodb_buffer_hot_cache_reused_pages | Global | The quantity of pages reused by Hotcache. |
Last updated: 2026.05.28 15:17:49
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