How to Improve MySQL Server Performance with Proper Optimization

7. Setting Up Cache for MyISAM

Setting the Buffer Key Size for MyISAM

The buffer key (key_buffer_size) is the primary cache used by the MyISAM storage engine to store indexes. Proper setting of the key_buffer_size is essential to ensure optimal performance because frequently accessed indexes are stored in a buffer, reducing the need for slower disk access.

key_buffer_size: The size of the buffer key determines how much memory is allocated to store the MyISAM index. This setting should be adjusted based on the amount of physical memory available and the amount of data accessed periodically. In general, if your server uses MyISAM exclusively, you can allocate between 25-30% of the total physical memory to key_buffer_size.

Example settings in the MySQL configuration file (my.cnf):

[mysqld]

key_buffer_size = 4G

This customization allows MySQL to store more indexes in memory, which can speed up frequently executed searches and queries.

Using Multiple Key Buffers for MyISAM

On some versions of MySQL, it is possible to use multiple key caches for MyISAM. This can be useful in situations where you want to allocate different caches to different tables or groups of tables, thus improving performance in a more controlled and granular way.

Setting up Multiple Key Buffers:

You can create multiple key buffers and allocate specific tables to those buffers. This is done by using SQL commands such as CACHE INDEX and LOAD INDEX INTO CACHE. However, note that this feature is used less frequently and may not be supported in all versions of MySQL.

Example settings for using multiple key buffers:

— Create additional key buffers

SET GLOBAL keycache1.key_buffer_size=2G;

SET GLOBAL keycache2.key_buffer_size=2G;

— Allocating tables to specific key buffers

CACHE INDEX tabel1, tabel2 IN keycache1;

CACHE INDEX tabel3 IN keycache2;

— Loading indexes into the cache

LOAD INDEX INTO CACHE tabel1, tabel2, tabel3;

This way, you can allocate different buffer keys to different tables, allowing you to optimize memory usage according to the access patterns specific to those tables.

8. Setting Up the Cache for InnoDB

Setting the Buffer Pool Size for InnoDB

To improve InnoDB’s performance, one of the important steps is to set the right buffer pool size. Here are the steps you can take:

1. Determine the Appropriate Buffer Pool Size:

• The ideal buffer pool size for InnoDB is typically around 80% of the server’s physical memory capacity. However, you can use more than that if the server has a lot of memory.
• Example: innodb_buffer_pool_size = 80% of total physical memory.

2. Set the Buffer Pool Size Based on Needs:

• If your server has a lot of memory, you can increase the size of the pool buffer by 90% or more.
• Example: innodb_buffer_pool_size = 90% of total physical memory.

3. Using InnoDB to Improve Performance:

• InnoDB is designed to optimize performance by using a large buffer pool to store data and indexes.
• By using InnoDB, you can reduce disk access and improve query performance.

Using InnoDB to Improve Performance

To use InnoDB effectively and improve performance, you can follow these steps:

1. Setting the Right InnoDB Parameters:

• Make sure InnoDB parameters such as innodb_buffer_pool_size, innodb_log_file_size, and innodb_flush_log_at_trx_commit are tailored to your server’s needs.
• Example: innodb_buffer_pool_size = 80% of total physical memory.

2. Using Buffer Pools to Improve Performance:

• Use a buffer pool to store data and indexes, which can reduce disk access and improve query performance.
• Example: innodb_buffer_pool_size = 80% of total physical memory.

3. Optimizing Performance by Using InnoDB:

• Use InnoDB to optimize performance by using a large buffer pool to store data and indexes.
• Example: innodb_buffer_pool_size = 80% of total physical memory.

9. Testing and Monitoring

Using Tools to Measure Cache Performance

To measure cache performance, you can use several tools provided by MySQL. Here are some ways to measure cache performance:

1. Using SHOW STATUS and SHOW VARIABLES:

You can use the SHOW STATUS and SHOW VARIABLES commands to measure cache performance. Example:

SHOW STATUS LIKE 'Key_reads';

SHOW STATUS LIKE 'Key_read_requests';

SHOW STATUS LIKE 'Key_blocks_unused';

SHOW STATUS LIKE 'key_buffer_size';

2. Using innotop:

Innotop is a tool that can help you measure the performance of InnoDB in more detail. Example:

innotop -i 10 --status

3. Using the mysqladmin command:

You can use the mysqladmin command to measure cache performance continuously. Example:

mysqladmin extended-status -r -i 10 | grep Key_reads

Calculating the Cache Hit Rate and Buffer Percentage Used

To calculate the cache hit ratio and buffer percentage used, you can use some equations provided by MySQL. Here are some ways to calculate it:

1. Calculating the Cache Hit Rate:

The cache hit ratio can be calculated using the equation:

Cache hit ratio = 10 - ((Key_reads *  100) /  Key_read_requests)

Example:

mysql> SHOW STATUS LIKE 'Key_reads';
+---------------+--------+
| Variable_name | Value  |
+---------------+--------+
| Key_reads     | 100    |
+---------------+--------+
mysql> SHOW STATUS LIKE 'Key_read_requests';
+-------------------+--------+
| Variable_name     | Value  |
+-------------------+--------+
| Key_read_requests | 1000  |
+-------------------+--------+
mysql> SELECT 100 - ((100 * 100) / 1000);
+-----------------------+
| 99.00                 |
+-----------------------+

2. Calculating the Percentage of Buffers Used:

The percentage of buffers used can be calculated using the equation:

Percentage of buffer in use = 100 – ((Key_blocks_unused * key_cache_block_size) * 100 / key_buffer_size)

Example:

mysql> SHOW STATUS LIKE 'Key_blocks_unused';
+-------------------+--------+
| Variable_name     | Value  |
+-------------------+--------+
| Key_blocks_unused  | 1000  |
+-------------------+--------+
mysql> SHOW VARIABLES LIKE 'key_buffer_size';
+-----------------------+--------+
| Variable_name        | Value  |
+-----------------------+--------+
| key_buffer_size      | 1024M |
+-----------------------+--------+
mysql> SELECT 100 - ((1000 * 1024 * 1024) / (1024 * 1024));
+-----------------------+
| 99.00                 |
+-----------------------+