MySQL SHOW STATUS - 接続数を確認する
コマンド
$ mysql -uroot -e 'show status' | grep -E 'Max|Threads' Max_used_connections 12 Threads_cached 0 Threads_connected 1 Threads_created 13280 Threads_running 1
Max_used_connections
The maximum number of connections that have been in use simultaneously since the server started.
Threads_cached
The number of threads in the thread cache.
Threads_connected
The number of currently open connections.
Threads_created
The number of threads created to handle connections. If Threads_created is big, you may want to increase the thread_cache_size value. The cache miss rate can be calculated as Threads_created/Connections.
Threads_running
The number of threads that are not sleeping.
http://dev.mysql.com/doc/refman/5.0/en/server-status-variables.html