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实时查看 mysql 当前连接数

首先进入 mysql 的bin目录,使用 mysqladmin 进行如下操作:

1、只查看当前连接数(Threads就是连接数):
./mysqladmin -u admin -p status

2、查看当前所有连接的详细资料:
./mysqladmin -u admin -p processlist

顺便说一下 mysqladmin 的命令和它们的含义:

./mysqladmin –help
./mysqladmin Ver 8.41 Distrib 5.0.51a, for redhat-linux-gnu on x86_64
Copyright (C) 2000-2006 MySQL AB
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL license

Administration program for the mysqld daemon.
Usage: ./mysqladmin [OPTIONS] command command….
-c, –count=# Number of iterations to make. This works with -i
(–sleep) only.
-#, –debug[=name] Output debug log. Often this is ‘d:t:o,filename’.
-f, –force Don’t ask for confirmation on drop database; with
multiple commands, continue even if an error occurs.
-C, –compress Use compression in server/client protocol.
–character-sets-dir=name
Directory where character sets are.
–default-character-set=name
Set the default character set.
-?, –help Display this help and exit.
-h, –host=name Connect to host.
-p, –password[=name]
Password to use when connecting to server. If password is
not given it’s asked from the tty.
-P, –port=# Port number to use for connection.
–protocol=name The protocol of connection (tcp,socket,pipe,memory).
-r, –relative Show difference between current and previous values when
used with -i. Currently works only with extended-status.
-O, –set-variable=name
Change the value of a variable. Please note that this
option is deprecated; you can set variables directly with
–variable-name=value.
-s, –silent Silently exit if one can’t connect to server.
-S, –socket=name Socket file to use for connection.
-i, –sleep=# Execute commands again and again with a sleep between.
-u, –user=name User for login if not current user.
-v, –verbose Write more information.
-V, –version Output version information and exit.
-E, –vertical Print output vertically. Is similar to –relative, but
prints output vertically.
-w, –wait[=#] Wait and retry if connection is down.
–connect_timeout=#
–shutdown_timeout=#

Variables (–variable-name=value)
and boolean options {FALSE|TRUE} Value (after reading options)
——————————— —————————–
count     0
force       FALSE
compress    FALSE
character-sets-dir                  (No default value)
default-character-set     (No default value)
host      (No default value)
port       3306
relative                           FALSE
socket                             /tmp/mysql.sock
sleep                              0
user                                 (No default value)
verbose          FALSE
vertical                              FALSE
connect_timeout       43200
shutdown_timeout      3600

Default options are read from the following files in the given order:
/etc/my.cnf ~/.my.cnf /usr/local/mysql/etc/my.cnf
The following groups are read: mysqladmin client
The following options may be given as the first argument:
–print-defaults Print the program argument list and exit
–no-defaults Don’t read default options from any options file
–defaults-file=# Only read default options from the given file #
–defaults-extra-file=# Read this file after the global files are read

Where command is a one or more of: (Commands may be shortened)
create databasename Create a new database
debug Instruct server to write debug information to log
drop databasename Delete a database and all its tables
extended-status Gives an extended status message from the server
flush-hosts Flush all cached hosts
flush-logs Flush all logs
flush-status Clear status variables
flush-tables Flush all tables
flush-threads Flush the thread cache
flush-privileges Reload grant tables (same as reload)
kill id,id,… Kill mysql threads
password new-password Change old password to new-password, MySQL 4.1 hashing.
old-password new-password Change old password to new-password in old format.

ping Check if mysqld is alive
processlist Show list of active threads in server
reload Reload grant tables
refresh Flush all tables and close and open logfiles
shutdown Take server down
status Gives a short status message from the server
start-slave Start slave
stop-slave Stop slave
variables Prints variables available
version Get version info from server