提高MySQL服务的性能,响应速度:
1.替换有问题的硬件:内存,CPU,磁盘
2.服务的配置参数的配置
3.SQL的优化
1.服务参数的配置: 1.1 连接数,连接超时: max_connections=1000 connect_timeout=50#等待建立连接的超时数,只有在登录时有效,默认是10秒 wait_timeout=120#等待关闭连接的不活动的超时时间,默认8小时,28800秒 2.优化SQL查询: 2.0 slow_query_log=1 2.1 slow_query_log_file=mysql-slow.log 2.2 long_query_time=5 2.3 log_queries_not_using_indexes=1 service mysql restart
#mysqldumpslow
3.理想比率 mysql> show global status like 'Max_used_connections'; +----------------------+-------+ | Variable_name | Value | +----------------------+-------+ | Max_used_connections | 28 | +----------------------+-------+ 1 row in set (0.00 sec) mysql> show variables like '%max_connections%'; +-----------------+-------+ | Variable_name | Value | +-----------------+-------+ | max_connections | 151 | +-----------------+-------+ 1 row in set (0.00 sec) 'Max_used_connections' / max_connections <85% ####################################### mysql> show global status like 'open%tables%'; +---------------+-------+ | Variable_name | Value | +---------------+-------+ | Open_tables | 64 | | Opened_tables | 4994 | 大-->缓存太小,不断的打开表 +---------------+-------+ mysql> show variables like 'table_open_cache'; +------------------+-------+ | Variable_name | Value | +------------------+-------+ | table_open_cache | 64 | -- 设置成max_connection 512 +------------------+-------+ set global table_open_cache=1024;
https://www.cnblogs.com/fjping0606/p/6531292.html
Open_tables / Opened_tables >= 0.85
Open_tables / table_open_cache <= 0.95
4.缓存参数控制: mysql> show variables like 'thread%size'; +-------------------+-------+ | Variable_name | Value | +-------------------+-------+ | thread_cache_size | 0 | -- 可重用线程数 +-------------------+-------+ mysql> show global status like 'threads%'; +-------------------+-------+ | Variable_name | Value | +-------------------+-------+ | Threads_cached | 0 | | Threads_connected | 27 | 线程重用情况 | Threads_created | 91 | | Threads_running | 2 | +-------------------+-------+ https://www.oschina.net/question/17_525 Threads_created表示创建过的线程数,如果发现Threads_created值过大的话, 表明 MySQL服务器一直在创建线程,这也是比较耗资源,可以适当增加配置文件中thread_cache_size值 https://www.landui.com/help/show-1609.html