Ben*_*Ben 5 mysql innodb query-optimization database-performance mysql-slow-query-log
在我的慢查询日志中,我看到的是慢查询
# Time: 121107 16:34:02 # User@Host: web_node[web_node] @ localhost [127.0.0.1] # Thread_id: 34436186 Schema: test_db Last_errno: 0 Killed: 0 # Query_time: 1.413751 Lock_time: 0.000222 Rows_sent: 203 Rows_examined: 203 Rows_affected: 0 Rows_read: 203 # Bytes_sent: 7553 Tmp_tables: 0 Tmp_disk_tables: 0 Tmp_table_sizes: 0 # InnoDB_trx_id: 9B04384 SET timestamp=1352334842; SELECT id, email FROM test_data WHERE id IN (13089576,3002681,3117763,1622233,2941590,12305279,1732672,2446772,3189510,13084725,4943929,5855071,6572137,2266261,3003496,2024860,3336832,13758671,6477694,1796684,13001771,4690025,1071744,1017876,5175795,795988,1619821,2481819,2941090,4770802,13438250,3254708,2323402,526303,13219855,3313573,3190479,1733761,3300577,2941758,6474118,1733379,11523598,4205064,6521805,2492903,1860388,3337093,5205317,1213970,5442738,12194039,1214203,12970536,3076611,3126152,3677156,5305021,2751587,4954875,875480,2105172,5309382,12981920,5204330,13729768,3254503,5030441,2680750,590661,1338572,7272410,1860386,2567550,5434143,1918035,5329411,1683235,3254119,5175784,1855380,3336834,2102567,4749746,37269,3207031,6464336,2227907,2713471,3937600,2940442,2233821,5619141,5204711,5988803,5050821,10109926,5226877,5050275,1874115,13677832,5338699,2423773,6432937,6443660,1990611,6090667,6527411,6568731,3254846,3414049,2011907,5180984,12178711,8558260,3130655,5864745,2059318,3480233,2104948,2387703,1939395,5356002,2681209,1184622,1184456,10390165,510854,7983305,795991,2622393,4490187,9436477,5356051,2423464,5205318,1600499,13623229,3255205,12200483,6477706,3445661,5226284,1176639,13760962,2101681,6022818,12909371,1732457,2377496,7260091,12191702,2492899,2630691,13047691,1684470,9382108,2233737,13117701,1796698,2535914,4941741,4565958,1100410,2321180,13080467,813342,4563877,4689365,2104756,1102802,2714488,3188947,1599770,1558291,5592740,5233428,5204830,1574452,3188956,13693326,2102349,3704111,1748303,790889,9323280,4741494,2387900,5338213,3583795,2283942,3189482,3002296,4490123,3585020,962926,3481423,1600920,1682364,4693123,6487778,2677582,2377195);
当我使用SQL_NO_CACHE通过探查器运行慢速查询时,它看起来如此
203 rows in set (0.03 sec) show profile for query 33; +----------------------+----------+ | Status | Duration | +----------------------+----------+ | starting | 0.000187 | | checking permissions | 0.000012 | | Opening tables | 0.000034 | | System lock | 0.000016 | | init | 0.000087 | | optimizing | 0.000024 | | statistics | 0.028694 | | preparing | 0.000074 | | executing | 0.000005 | | Sending data | 0.001596 | | end | 0.000009 | | query end | 0.000008 | | closing tables | 0.000014 | | freeing items | 0.001600 | | logging slow query | 0.000007 | | cleaning up | 0.000011 | +----------------------+----------+
当我用解释运行查询时说
+----+-------------+------------------+-------+------------------+----------+---------+------+------+--------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+------------------+-------+------------------+----------+---------+------+------+--------------------------+ | 1 | SIMPLE | test_data | range | PRIMARY,id_email | id_email | 4 | NULL | 203 | Using where; Using index | +----+-------------+------------------+-------+------------------+----------+---------+------+------+--------------------------+
create table看起来像
CREATE TABLE `test_data` ( `id` int(11) NOT NULL AUTO_INCREMENT, `email` varchar(254) DEFAULT NULL, `domain` varchar(254) DEFAULT NULL, `age` smallint(6) DEFAULT NULL, `gender` tinyint(1) DEFAULT NULL, `location_id` int(11) unsigned DEFAULT NULL, `created` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00', `unistall_date` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00', `subscription_date` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00', `active` tinyint(1) DEFAULT '1', PRIMARY KEY (`id`), UNIQUE KEY `email` (`email`), KEY `domain` (`domain`), KEY `id_email` (`id`,`email`), KEY `email_id` (`email`,`id`) ) ENGINE=InnoDB AUTO_INCREMENT=13848530 DEFAULT CHARSET=utf8
还有另一个查询定期运行,从电子邮件地址列表中选择ID和电子邮件,因此电子邮件,ID密钥,电子邮件地址需要是唯一的,因此为什么这是一个唯一的密钥.该表只有~14M行
我想也许索引的内存和交换变大,但盒子有8演出的内存.
SELECT table_schema "Data Base Name", SUM( data_length + index_length) / 1024 / 1024 "Data Base Size in MB", SUM( index_length) / 1024 / 1024 "Index Size in MB" FROM information_schema.TABLES GROUP BY table_schema; +--------------------+----------------------+------------------+ | Data Base Name | Data Base Size in MB | Index Size in MB | +--------------------+----------------------+------------------+ | metrics | 3192.50000000 | 1594.42187500 | | data | 8096.48437500 | 5639.51562500 | | raw_data | 6000.35937500 | 745.07812500 | | information_schema | 0.00878906 | 0.00878906 | | mysql | 0.04319191 | 0.04101563 | | performance_schema | 0.00000000 | 0.00000000 | +--------------------+----------------------+------------------+
在my.cnf文件中设置innodb_file_per_table = 1似乎解决了这个问题.
这改善了执行时间,我的理解是每个表具有单个文件意味着磁盘针不需要移动如此大的距离.
问题
更新
最初没有/etc/my.cnf文件,然后我用以下内容创建了一个
[mysqld] server-id=1 max_connections=1500 key_buffer_size=50M query_cache_limit=16M query_cache_size=256M thread_cache=16 table_open_cache=4096 sort_buffer_size=512K join_buffer_size=8M read_buffer_size=8M skip_name_resolve=1 thread_cache_size=256 innodb_buffer_pool_size=6G innodb_buffer_pool_instances=1 innodb_thread_concurrency=96 innodb_additional_mem_pool_size=32M innodb_log_buffer_size=8M innodb_flush_log_at_trx_commit=0 innodb_log_file_size=256M innodb_flush_method=O_DIRECT innodb_file_per_table=1 net_read_timeout=15 net_write_timeout=30 log-bin=mysql-bin sync_binlog=0 datadir=/var/lib/mysql
您的 innodb_log_buffer 数据过多。
以下各项的价值是什么：
innodb_buffer_pool_size
innodb_log_file_size
所有InnoDB都必须在内存中运行。当您拆分文件时，它的运行效率会更高，因为它会以更少的磁盘读写次数换入和换出内存，因为一个较大的文件需要更长的时间来扫描数据。
它不会交换，因为你的 innodb_buffer_pool_size 限制了 MySQL 加载到内存中的内存量。
解决问题的唯一方法是获取更多内存并为所有 innodb 表和索引分配足够的 innodb_buffer_pool_size 。