How to improve performance by optimizing MySQL server cache

MySQL database is the core technology for modern web application backend development. However, with the growth of data volume and increasing access, the performance of MySQL server will become a bottleneck affecting application performance, so optimizing the MySQL server cache will become An important way to improve application performance.

The cache of MySQL server refers to storing the most frequently used database objects such as tables, views, indexes, etc. in memory to quickly respond to client query requests. The cache of the MySQL server consists of the following three components:

1. Query Cache: The MySQL server caches the query results so that the next time the same result is queried, the results can be obtained directly from the cache. Ensure low latency and efficient query response time.

2. Table Cache: MySQL server caches open tables to speed up the efficiency of secondary access. For table caches with a large number of frequently accessed tables, it can effectively reduce disk read and write operations and improve the overall performance.

3. Key Cache: The MySQL server caches the data of the table index. It is responsible for caching the nodes, keys and data of the index. This cache is typically kept in memory to allow for quick retrieval and reading of index data when the cache is hit.

The following are some commonly used methods to optimize MySQL server cache, which can improve MySQL performance:

1. Optimize query cache (Query Cache) settings:

The query cache stores query results so that the MySQL server can quickly respond to subsequent query requests. However, the query cache has flaws. When the data in the MySQL server changes, its cache is cleared, causing the MySQL server to regenerate the results when querying again, which limits the applicability of the query cache. Therefore, it is recommended to set the query cache appropriately according to the actual situation. If it can be avoided, the query cache should be turned off to avoid additional performance overhead.

2. Increase table cache (Table Cache):

MySQL server will use the table cache to save data such as open file handles and file descriptors. This cache helps the MySQL server quickly access database table information. By default, the table cache size is relatively small, and the MySQL server is prone to encounter performance bottlenecks when processing a large number of tables. In order to optimize the performance of the MySQL server, the size of the table cache should be increased to support a greater number of simultaneous accesses.

3. Maintaining table indexes (Key Cache):

Maintaining table indexes is an important task in the MySQL server. It can improve search efficiency and optimize query speed. In order to increase the impact of the key cache in the MySQL server on database performance, the cache size should be adjusted and a reasonable update frequency should be maintained so that expired caches can be deleted in a timely manner. In addition, for large MySQL servers, you can choose to use the InnoDB storage engine to improve the efficiency of index operations.

4. Share lightweight query caching:

If you are using MySQL server to support multiple applications, the problem may become more complicated, and the individual applications The query cache may affect each other, so it is recommended to set up a lightweight query cache appropriately and ensure it is available to all applications.

5. Use memory storage engine:

Each object in the MySQL server can be managed through the storage engine. Under the same size memory limit, the storage engine needs to process more metadata information, resulting in more memory allocation and release, which will reduce the performance of the MySQL server. Therefore, it is recommended to use an in-memory storage engine, such as Memory, to speed up the performance of the MySQL server.

6. Close unnecessary logs:

MySQL server will record various types of log information, including binary files, error logs, update logs, etc. Turning off unnecessary logs may have a positive impact on the performance of your MySQL server. With appropriate log level settings and filtering, you can reduce logging on your MySQL server, thereby optimizing performance.

Summary:

The importance of optimizing the MySQL server cache is obvious. Through the above methods, the performance of the application can be improved without increasing hardware costs and network bandwidth, and it can provide Provide guarantee for the stable operation of MySQL server. It is recommended that users adopt the above-mentioned methods of optimizing the MySQL server cache in actual applications and regularly check its performance to ensure the optimal status of the MySQL server and the operation of applications under the highest performance conditions.

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