How to modify the maximum number of mysql concurrent connections does not matter to MySQL. It mainly depends on the system and business logic. Method 1: Go to the MySQL installation directory and open the MYSQL configuration file my. ini or my. cnf query max_connections = 100 modify to max_connections = 1000 restart MYSQL in the service to www.2cto.com Method 2: the maximum number of connections of MySQL is 100 Client Login by default: mysql-uusername-ppassword sets the new maximum number of connections to 200: mysql> set GLOBAL max_connections = 200 to display the currently running Query: mysql> show processlist to display the current status: mysql> show status exit the client: mysql> exit www.2cto.com to view the current maximum number of connections: mysqladmin-uusern Method 3 of ame-ppassword variables: Take mysql 5.0.33 manually compiled version under centos 4.4 as an example: vi/usr/local/mysql/bin/mysqld_safe find safe_mysqld and edit it, find the two lines started by mysqld, and add the parameter "-O max_connections = 1500" to the end. The specific point is the location below: export then $ export $ ledir/$ MYSQLD $ defaults -- basedir = $ MY_BASEDIR_VERSION -- datadir = $ DATADIR $ USER_OPTION -- pid-file = $ pid_file -- skip-external-locking-O max_connections = 1500 >>>$ err_log 2> & 1 Else eval "$ export $ ledir/$ MYSQLD $ defaults -- basedir = $ MY_BASEDIR_VERSION -- datadir = $ DATADIR $ USER_OPTION -- pid-file = $ pid_file -- skip-external-locking $ args- O max_connections = 1500> $ err_log 2> & 1 "Save. # Service mysqld restart #/usr/local/mysql/bin/mysqladmin-uroot-p variables after entering the password of the root database account, you can see that www.2cto.com max_connections 1500 indicates that the new change has taken effect. Another way is to modify the original code: Unlock the original MySQL code and go to the SQL directory to modify mysqld. find The following line for cc: {"max_connections", OPT_MAX_CONNECTIONS, "The number of simultaneous clients allowed. ", (gptr *) & max_connections, (gptr *) & max_connections, 0, GET_ULONG, REQUIRED_ARG, 100, 1, 16384, 0, 1, 0}, change it: www.2cto.com {"max_connections", OPT_MAX_CONNECTIONS, "The number of simultaneous clients allowed. ", (gptr *) & max_connections, (gptr *) & max_conne Functions, 0, GET_ULONG, REQUIRED_ARG, 1500, 1, 16384, 0, 1, 0}, save the disk and exit./configure; make install can achieve the same effect.