[root@document-system bin]# mysqlslap -hlocalhost -uroot -proot -P3306 --concurrency=1000 --iterations=1 --auto-generate-sql --auto-generate-sql-load-type=mixed --auto-generate-sql-add-autoincrement --engine=innodb --number-of-queries=1000 --debug-info
Warning: Using a password on the command line interface can be insecure.
Benchmark
Running for engine innodb
Average number of seconds to run all queries: 0.060 seconds
Minimum number of seconds to run all queries: 0.060 seconds
Maximum number of seconds to run all queries: 0.060 seconds
Number of clients running queries: 1000
Average number of queries per client: 1
User time 0.08, System time 0.43
Maximum resident set size 28220, Integral resident set size 0
Non-physical pagefaults 7459, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 16324, Involuntary context switches 39上图中是在mysql的bin目录下执行的命令。我们可以看出1000的并发量对于单个数据库而言是没有问题的，下面看5000的并发量：
[root@document-system bin]# mysqlslap -hlocalhost -uroot -proot -P3306 --concurrency=5000 --iterations=1 --auto-generate-sql --auto-generate-sql-load-type=mixed --auto-generate-sql-add-autoincrement --engine=innodb --number-of-queries=5000 --debug-info
Warning: Using a password on the command line interface can be insecure.
Benchmark
Running for engine innodb
Average number of seconds to run all queries: 0.598 seconds
Minimum number of seconds to run all queries: 0.598 seconds
Maximum number of seconds to run all queries: 0.598 seconds
Number of clients running queries: 5000
Average number of queries per client: 1
User time 0.53, System time 1.88
Maximum resident set size 134844, Integral resident set size 0
Non-physical pagefaults 30313, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 96141, Involuntary context switches 33这时候数据库就有点吃力了，再看12000的并发量：
[root@document-system bin]# mysqlslap -hlocalhost -uroot -proot -P3306 --concurrency=12000 --iterations=1 --auto-generate-sql --auto-generate-sql-load-type=mixed --auto-generate-sql-add-autoincrement --engine=innodb --number-of-queries=12000 --debug-info
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 2001 Can't create UNIX socket (24)
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
mysqlslap: Error when connecting to server: 1040 Too many connections
Benchmark
Running for engine innodb
Average number of seconds to run all queries: 1.141 seconds
Minimum number of seconds to run all queries: 1.141 seconds
Maximum number of seconds to run all queries: 1.141 seconds
Number of clients running queries: 12000
Average number of queries per client: 1
User time 1.68, System time 4.36
Maximum resident set size 303504, Integral resident set size 0
Non-physical pagefaults 68515, Physical pagefaults 0, Swaps 0
Blocks in 0 out 0, Messages in 0 out 0, Signals 0
Voluntary context switches 271921, Involuntary context switches 81
这时候MySQL就拒绝了部分请求。所以单节点数据库的查询并发超过10000，就扛不住了。
参考：https://blog.csdn.net/zhang123456456/article/details/73089195