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How does the InnoDB buffer pool work in MySQL?
Knowing how the InnoDB buffer pool works, and taking advantage of it to keep frequently accessed data in memory, is an important aspect of MySQL tuning. For an explanation of the inner workings of the InnoDB buffer pool, an overview of its LRU replacement algorithm, and general configuration information, see Section 15.5.1, “Buffer Pool” .
Where can I find InnoDB standard monitor output?
InnoDB Standard Monitor output, which can be accessed using “SHOW ENGINE INNODB STATUS”, provides a number of metrics pertaining to operation of the InnoDB buffer pool, under the BUFFER POOL AND MEMORY section. Here is some typical content:
How big should the chunk size be in InnoDB?
Chunk size is defined by the innodb_buffer_pool_chunk_size configuration option, which has a default of 128M. For more information, see Configuring InnoDB Buffer Pool Chunk Size . Buffer pool size must always be equal to or a multiple of innodb_buffer_pool_chunk_size * innodb_buffer_pool_instances . If you configure innodb_buffer_pool_size
How to improve InnoDB performance in MySQL 5.5.4?
MariaDB/MySQL 5.5.4 introduces new configuration settings for the InnoDB storage engine. This can greatly improve MySQL’s InnoDB performance, both in read and write operations. One of those settings is innodb_buffer_pool_instances. The innodb_buffer_pool_instances divides the InnoDB buffer pool into separate instances.
When to increase the value of InnoDB read io threads?
When you see more than 64 × innodb_read_io_threads pending read requests in SHOW ENGINE INNODB STATUS, you might gain by increasing the value of innodb_read_io_threads.
How to clear the buffer pool in MySQL?
Please note that most operating systems will cache (files) in the same way- unless memory is used for other things, they will try to fit as much data as possible in memory. Restarting the server will usually clear most of the buffer pool unless configured to be preloaded.
InnoDB maintains a storage area called the buffer pool for caching data and indexes in memory. Knowing how the InnoDB buffer pool works, and taking advantage of it to keep frequently accessed data in memory, is an important aspect of MySQL tuning.
How to tune the MySQL key buffer performance?
It’s important to get that rate as close to 100% as possible. For large databases, however, 95%-99% is the best that can be achieved and indicates a well tuned system. The MyISAM storage engine uses a key buffer for caching index data from disk.
How big of a buffer do I need for MySQL?
[mysqld] set-variable = innodb_buffer_pool_size = 512M If a system is being configured to run solely as a database server using the InnoDB storage engine, this configuration could be set up to 80% of total system memory for the best effect.
How is the MyISAM key buffer used in MySQL?
Unlike the InnoDB buffer pool, the MyISAM key buffer will not pre-allocate itself at MySQL startup, but will instead only be used as required, so having a high setting for a small database will not do any harm. In order to evaluate the performance of the MyISAM key buffer, you may look at the MySQL status like so: