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