Help with mysql

Question

MySQL

At 3 am, the base was hit like a hammer. All requests in Sending data…
Even primitive requests like select id are executed for half an hour.
There is no load on the server. LA 0, Mysql eats 600% CPU.

Since 3 am, I can’t solve the problem in any way ...
Absolutely nothing has changed either in scripts or in configs. Everything worked perfectly for several months.

Answer 1

1. Make sure that everything is OK with the disks. Maybe they just ate all the IO (the raid fell apart, for example.)
2. Make sure that you do not have a sudden fragmentation of the database.
3. Remove the load from the muscle and make sure that it somehow works without it (eg log in and request a list of processes)
4. Make sure that the show processlist is an adequate picture.
Usually this is enough.

Answer 2

I would check the disks if possible. Especially if it's a single drive without a raid.

Answer 3

Restarting MySQL doesn't help? What OS, what version, what interfaces are used (php-mysql, php-mysqli, php-mysqlnd, PDO, etc...)

Answer 4

Try reloading the hanging tables with mysqldump.

Answer 5

It helped us to upgrade to mysql 5.6

Answer 6

Exactly the same symptoms with innodb + file-per-table + commonly used temporary tables.