Base performance_schema drop et create

Bonjour,

J'ai vu ces requêtes dans mes logs mysql :


11 Query SET @cmd= "DROP DATABASE IF EXISTS performance_schema"
11 Prepare DROP DATABASE IF EXISTS performance_schema
11 Execute DROP DATABASE IF EXISTS performance_schema
11 Query SET @cmd= "CREATE DATABASE performance_schema character set utf8"
11 Prepare CREATE DATABASE performance_schema character set utf8
11 Execute CREATE DATABASE performance_schema character set utf8

Est-ce quelque chose de normal ?
Qu'est-ce qui a pu provoquer ceci.

Merci