Check connection issue of mysql

#show connection configuration
show variables like '%max_connection%';

#Change the limitation of max_connection temporarily
set global max_connections=600;

#check current status
status;

#check how many processes running
show processlist;

#Kill the locked connections
for id in `mysqladmin processlist | grep -i locked | awk '{print $1}'`
do
mysqladmin kill ${id}
done

#Run killing sql

source kill_thread_id.sql