… amazing MySQL manual, especially the option and …key_cache_age_thresholdblogpercona.commanual key_cache_block_sizeblogpercona.commanual key_cache_division_limitblogpercona.commanual Key_read_requestsblogpercona.commanual Key_readsblogpercona.commanual Key_write_requestsblogpercona.commanual Key…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
… like “key%”; +————————+———+ | Variable_name | Value | +————————+———+ | Key_blocks_not_flushed | 6516 | | Key_blocks_unused | 0 | | Key_blocks_used | 7248 | | Key_read_requests | 2051451 | | Key_reads | 198208 | | Key_write_requests | 469220 | | Key_writes | 185808 | +————————+———+ 7 rows in set (0.00 sec) So how long does it take: mysql> select…
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…write‘, ’292923929′ ‘Key_blocks_not_flushed’, ’0′ ‘Key_blocks_unused’, ’28987′ ‘Key_blocks_used’, ’1332′ ‘Key_read_requests‘, ’1552507′ ‘Key_reads’, ’1654′ ‘Key_write_requests‘, ’114303′ ‘Key_writes…
Post: What MySQL buffer cache hit rate should you target
June 29, 2006 By 5 Comments
…were drives with concurrent requests, how random were these reads/writes, how good was OS…partuclar you should be looking at Key_reads and Key_writes for MyISAM tables (note this…writes” from SHOW INNODB STATUS for Innodb tables. In MySQL 5.0+ you can also use Innodb_data_reads, and Innodb_data_writes…
Comment: What to tune in MySQL Server after installation
September 5, 2008 By 116 Comments
… you please tell me what are the settings required in mysql for incressing performance of my project. Also can you please… are the my server ‘SHOW STATUS’ output; Key_read_requests 9490927 Key_reads 72073 Key_write_requests 678314 Key_writes 430602 Open_tables 561 Open_files 278 Thanks…
Comment: Why MySQL could be slow with large tables ?
November 14, 2008 By 139 Comments
…_tables 5,274 Created_tmp_files 37 k Key_reads 4,226 Key_write_requests 380 k Key_writes 367 k Sort_merge_passes 18 k Sort_rows 12 M — Actual my.cnf: [mysqld] datadir = /var/lib/mysql socket = /var/lib/mysql/mysql.sock user=mysql # Default to using old password format for compatibility with mysql 3.x # clients…
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
… many requests for help with server stalls. They come under various names…of them quickly and conclusively with no guesswork. The key is to use a logical approach and good tools…. in MySQL, and they usually begin microscopically and get worse over time, sometimes abruptly worse. I’ll try to write…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
… interesting question it brings – how many read-ahead requests can be queued at once. Q13: Is there… not think so. Sergei Golubchik serialized the MySQL binlog write and the InnoDB log flush with a mutex… in the same order in the foreign key and the referenced key (this same order condition could be …
Post: Active Cache for MySQL
January 10, 2010 By 11 Comments
… for the same key we get a lot of requests when it is expired cache could decide to refresh such keys based on… max_age specified on GET request. In many applications expiration is not data driven but rather request driven. Consider for example posting…. Finally I think Active Cache could be very helpful handling write back scenarios. There are many cases when there is a…
Post: MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 10 Comments
… to write an overview of these two approaches to hosting MySQL in the Amazon cloud. In general, MySQL performance…stalls to quite severe stalls as I/O requests stack up and other things block against them…. need to at least mention the existence of key advantages at the technical level. These include …
