MySQL常用配置和性能压力测试：MySQL系列之十五

一、MySQL常用配置

以下所有配置参数以32G内存的服务器为基

1、打开独立的表空间

innodb_file_per_table = 1

2、MySQL服务所允许的同时会话数的上限，默认为151，经常出现Too Many Connections的错误提示，则需要增大此值

max_connections = 8000

3、操作系统在监听队列中所能保持的连接数

back_log = 300

4、每个客户端连接最大的错误允许数量，当超过该次数，MYSQL服务器将禁止此主机的连接请求，直到MYSQL服务器重启或通过flush hosts命令清空此主机的相关信息

max_connect_errors = 1000

5、所有线程所打开表的数量

open_files_limit = 10240

6、每个连接传输数据大小，最大1G，须是1024的倍数，一般设为最大的BLOB的值

max_allowed_packet = 32M

7、请求的最大连接时间

wait_timeout = 10

8、排序缓冲被用来处理类似ORDER BY以及GROUP BY队列所引起的排序

sort_buffer_size = 16M

9、不带索引的全表扫描，使用的buffer的最小值

join_buffer_size = 16M

10、查询缓冲大小

query_cache_size = 128M

11、指定单个查询能够使用的缓冲区大小，默认为1M

query_cache_limit = 4M

12、设定默认的事务隔离级别

transaction_isolation = REPEATABLE-READ

13、线程使用的堆大小，此值限制内存中能处理的存储过程的递归深度和SQL语句复杂性，此容量的内存在每次连接时被预留

thread_stack = 512K

14、开启二进制日志功能

log_bin

15、二进制日志格式：基于行

binlog_format = row

16、InnoDB使用一个缓冲池来保存索引和原始数据, 可设置这个变量到服务器物理内存大小的80%

innodb_buffer_pool_size = 6G

17、用来同步IO操作的IO线程的数量

innodb_file_io_threads = 4

18、在Innodb核心内的允许线程数量，建议的设置是CPU数量加上磁盘数量的两倍

innodb_thread_concurrency = 16

19、用来缓冲日志数据的缓冲区的大小

innodb_log_buffer_size = 16M

20、在日志组中每个日志文件的大小

innodb_log_file_size = 512M

21、在日志组中的文件总数

innodb_log_files_in_group = 3

22、SQL语句在被回滚前,InnoDB事务等待InnoDB行锁的时间

innodb_lock_wait_timeout = 120

23、慢查询记录的阈值时长，默认10秒

long_query_time = 2

24、将没有使用索引的查询也记录下来

log-queries-not-using-indexes

my.cnf示例：

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
symbolic-links=0
innodb_file_per_table = 1
innodb_buffer_pool_size = 6442450944  #内存不足6G会报错
innodb_file_io_threads = 4
innodb_thread_concurrency = 16
innodb_log_buffer_size = 16M
innodb_log_file_size = 512M
innodb_log_files_in_group = 3
innodb_lock_wait_timeout = 120
log_bin = /var/lib/mysql/mariadb-bin
binlog_format = row
slow_query_log
long_query_time = 2
log-queries-not-using-indexes
transaction_isolation = REPEATABLE-READ
query_cache_size = 128M
query_cache_limit = 4M
max_connections = 8000
back_log = 300
max_connect_errors = 1000
open_files_limit = 10240
max_allowed_packet = 32M
wait_timeout = 10
sort_buffer_size = 16M
join_buffer_size = 16M
thread_stack = 512K

二、MySQL的性能压力测试

常见测试工具：

mysqlslap
Sysbench
tpcc-mysql
MySQL Benchmark Suite
MySQL super-smack
MyBench

mysqlslap工具介绍

mysqlslap来自于mariadb包，测试的过程默认生成一个mysqlslap的schema,生成测试表t1，查询和插入测试数据，mysqlslap库自动生成，如果已经存在则先删除。用--only-print来打印实际的测试过程，整个测试完成后不会在数据库中留下痕迹。

常用选项：

--auto-generate-sql, -a 自动生成测试表和数据，表示用mysqlslap工具自己生成的SQL脚本来测试并发压力
--auto-generate-sql-load-type=type 测试语句的类型。代表要测试的环境是读操作还是写操作还是两者混合的。取值包括：read，key，write，update和mixed(默认)
--auto-generate-sql-add-auto-increment 代表对生成的表自动添加auto_increment列，从5.1.18版本开始支持
--number-char-cols=N, -x N 自动生成的测试表中包含多少个字符类型的列，默认1
--number-int-cols=N, -y N 自动生成的测试表中包含多少个数字类型的列，默认1
--number-of-queries=N 总的测试查询次数(并发客户数×每客户查询次数)
--query=name,-q 使用自定义脚本执行测试，例如可以调用自定义的存储过程或者sql语句来执行测试
--create-schema 代表自定义的测试库名称，测试的schema，MySQL中schema也就是database
--commint=N 多少条DML后提交一次
--compress, -C 如服务器和客户端都支持压缩，则压缩信息
--concurrency=N, -c N 表示并发量，即模拟多少个客户端同时执行select；可指定多个值，以逗号或者--delimiter参数指定值做为分隔符
--engine=engine_name, -e engine_name 代表要测试的引擎，可以有多个，用分隔符隔开
--iterations=N, -i N 测试执行的迭代次数，代表要在不同并发环境下，各自运行测试多少次
--only-print 只打印测试语句而不实际执行
--detach=N 执行N条语句后断开重连
--debug-info, -T 打印内存和CPU的相关信息

测试示例：

1）单线程测试

[root@centos7 ~]# mysqlslap -a -uroot -p
Enter password:
Benchmark
        Average number of seconds to run all queries: 0.004 seconds
        Minimum number of seconds to run all queries: 0.004 seconds
        Maximum number of seconds to run all queries: 0.004 seconds
        Number of clients running queries: 1
        Average number of queries per client: 0

2）多线程测试，使用–concurrency来模拟并发连接

[root@centos7 ~]# mysqlslap -uroot -p -a -c 500
Enter password:
Benchmark
        Average number of seconds to run all queries: 3.384 seconds
        Minimum number of seconds to run all queries: 3.384 seconds
        Maximum number of seconds to run all queries: 3.384 seconds
        Number of clients running queries: 500
        Average number of queries per client: 0

3）同时测试不同的存储引擎的性能进行对比

[root@centos7 ~]# mysqlslap -uroot -p -a --concurrency=500 --number-of-queries 1000 --iterations=5 --engine=myisam,innodb --debug-info
Enter password:
Benchmark
        Running for engine myisam
        Average number of seconds to run all queries: 0.192 seconds
        Minimum number of seconds to run all queries: 0.187 seconds
        Maximum number of seconds to run all queries: 0.202 seconds
        Number of clients running queries: 500
        Average number of queries per client: 2
Benchmark
        Running for engine innodb
        Average number of seconds to run all queries: 0.355 seconds
        Minimum number of seconds to run all queries: 0.350 seconds
        Maximum number of seconds to run all queries: 0.364 seconds
        Number of clients running queries: 500
        Average number of queries per client: 2
User time 0.33, System time 0.58
Maximum resident set size 22892, Integral resident set size 0
Non-physical pagefaults 46012, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 31896, Involuntary context switches 0

4）执行一次测试，分别500和1000个并发，执行5000次总查询

[root@centos7 ~]# mysqlslap -uroot -p -a --concurrency=500,1000 --number-of-queries 5000 --debug-info
Enter password:
Benchmark
        Average number of seconds to run all queries: 3.378 seconds
        Minimum number of seconds to run all queries: 3.378 seconds
        Maximum number of seconds to run all queries: 3.378 seconds
        Number of clients running queries: 500
        Average number of queries per client: 10
Benchmark
        Average number of seconds to run all queries: 3.101 seconds
        Minimum number of seconds to run all queries: 3.101 seconds
        Maximum number of seconds to run all queries: 3.101 seconds
        Number of clients running queries: 1000
        Average number of queries per client: 5
User time 0.84, System time 0.64
Maximum resident set size 83068, Integral resident set size 0
Non-physical pagefaults 139977, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 31524, Involuntary context switches 3

5）迭代测试

[root@centos7 ~]# mysqlslap -uroot -p -a --concurrency=500 --number-of-queries 5000 --iterations=5 --debug-info
Enter password:
Benchmark
        Average number of seconds to run all queries: 3.307 seconds
        Minimum number of seconds to run all queries: 3.184 seconds
        Maximum number of seconds to run all queries: 3.421 seconds
        Number of clients running queries: 500
        Average number of queries per client: 10
User time 2.18, System time 1.58
Maximum resident set size 74872, Integral resident set size 0
Non-physical pagefaults 327732, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 73904, Involuntary context switches 3