How Many innodb_buffer_pool_instances Do You Need in MySQL 8?
The number of innodb_buffer_pool_instances you need in MySQL 8 depends on your system's available memory, the size of your InnoDB buffer pool, and your workload. The InnoDB buffer pool is where MySQL stores data and indexes for InnoDB tables. The buffer pool is divided into multiple instances, each with its own buffer pool size and memory allocation. By default, MySQL 8 sets the number of innodb_buffer_pool_instances to 8. If you have a large amount of available memory, you can increase the number of instances to improve performance by allowing more parallelism in the buffer pool. However, if you have limited memory, increasing the number of instances will decrease the size of each instance, potentially resulting in decreased performance. For best results, you should test different settings for innodb_buffer_pool_instances with your specific workload and system configuration to find the optimal number for your use case. A good practice for choosing the number of innodb_buffer_pool_instances is to set it to the number of CPU cores or the number of NUMA nodes, whichever is lower. It's also important to note that the total size of buffer pool instances should not exceed the available RAM.