MySQL压力测试工具
mysqlslap --create-schema=example --query="SELECT * FROM group_message force index(group_message_author_subject) WHERE author = '3' subject LIKE 'weiurazs%'" --iterations=10000测试的过程需要生成测试表，插入测试数据，这个mysqlslap可以自动生成，默认生成一个mysqlslap的schema，如果已经存在则先删除，这里要注意了，不要用create-schema指定已经存在的库，否则后果可能很严重。可以用
only-print来打印实际的测试过程：
$mysqlslap -a only-print
DROP SCHEMA IF EXISTS mysqlslap;
CREATE SCHEMA mysqlslap;
use mysqlslap;
CREATE TABLE g_user (user_id INT(32) ,user_name VARCHAR(128));
INSERT INTO g_user VALUES (1,'liuxiaobin');
…
SELECT user_id,user_name FROM g_user;
INSERT INTO g_user VALUES (2,'liudabin');
DROP SCHEMA IF EXISTS mysqlslap;
可以看到最后由删除一开始创建的schema的动作，整个测试完成后不会在数据库中留下痕迹。假如我们执行一次测试，分别50和100个并发，执行1000次总查询，那么：
$mysqlslap -a concurrency=50,100 number-of-queries 1000 debug-info
Benchmark
Average number of seconds to run all queries: 0.375 seconds
Minimum number of seconds to run all queries: 0.375 seconds
Maximum number of seconds to run all queries: 0.375 seconds
Number of clients running queries: 50
Average number of queries per client: 20
Benchmark
Average number of seconds to run all queries: 0.453 seconds
Minimum number of seconds to run all queries: 0.453 seconds
Maximum number of seconds to run all queries: 0.453 seconds
Number of clients running queries: 100
Average number of queries per client: 10
User time 0.29, System time 0.11
Maximum resident set size 0, Integral resident set size 0
Non-physical pagefaults 4032, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 7319, Involuntary context switches 681
上结果可以看出，50和100个并发分别得到一次测试结果(Benchmark)，并发数越多，执行完所有查询的时间越长。为了准确起见，可以多迭代测试几次:
$ mysqlslap -a concurrency=50,100 number-of-queries 1000 iterations=5 debug-info
Benchmark
Average number of seconds to run all queries: 0.380 seconds
Minimum number of seconds to run all queries: 0.377 seconds
Maximum number of seconds to run all queries: 0.385 seconds
Number of clients running queries: 50
Average number of queries per client: 20
Benchmark
Average number of seconds to run all queries: 0.447 seconds
Minimum number of seconds to run all queries: 0.444 seconds
Maximum number of seconds to run all queries: 0.451 seconds
Number of clients running queries: 100
Average number of queries per client: 10
User time 1.44, System time 0.67
Maximum resident set size 0, Integral resident set size 0
Non-physical pagefaults 17922, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 36796, Involuntary context switches 4093
测试同时不同的存储引擎的性能进行对比：
$ mysqlslap -a concurrency=50,100 number-of-queries 1000 iterations=5 engine=myisam,innodb debug-info
Benchmark
Running for engine myisam
Average number of seconds to run all queries: 0.200 seconds
Minimum number of seconds to run all queries: 0.188 seconds
Maximum number of seconds to run all queries: 0.210 seconds
Number of clients running queries: 50
Average number of queries per client: 20
Benchmark
Running for engine myisam
Average number of seconds to run all queries: 0.238 seconds
Minimum number of seconds to run all queries: 0.228 seconds
Maximum number of seconds to run all queries: 0.251 seconds
Number of clients running queries: 100
Average number of queries per client: 10
Benchmark
Running for engine innodb
Average number of seconds to run all queries: 0.375 seconds
Minimum number of seconds to run all queries: 0.370 seconds
Maximum number of seconds to run all queries: 0.379 seconds
Number of clients running queries: 50
Average number of queries per client: 20
Benchmark
Running for engine innodb
Average number of seconds to run all queries: 0.443 seconds
Minimum number of seconds to run all queries: 0.440 seconds
Maximum number of seconds to run all queries: 0.447 seconds
Number of clients running queries: 100
Average number of queries per client: 10
User time 2.83, System time 1.66
Maximum resident set size 0, Integral resident set size 0
Non-physical pagefaults 34692, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 87306, Involuntary context switches 10326
MySQL从5.1.4版开始带有一个压力测试工具mysqlslap，通过模拟多个并发客户端访问mysql来执行测试，使用起来非常的简单。通过mysqlslap help可以获得可用的选项，
auto-generate-sql, -a
自动生成测试表和数据
auto-generate-sql-load-type=type
测试语句的类型。取值包括：read，key，write，update和mixed(默认)。
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一个存储过程或者sql语句来执行测试。
create-schema
测试的schema，MySQL中schema也就是database
commint=N
多少条DML后提交一次
compress, -C
如果服务器和客户端支持都压缩，则压缩信息传递
concurrency=N, -c N
并发量，也就是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参数指定的值做为分隔符
engine=engine_name, -e engine_name
创建测试表所使用的存储引擎，可指定多个
iterations=N, -i N
测试执行的迭代次数
detach=N
执行N条语句后断开重连
debug-info, -T
打印内存和CPU的信息
only-print
只打印测试语句而不实际执行