Too many open files


i have yesterday a failure about 30 minutes. Follow error message I received:

SQLSTATE[HY000]: General error: 23 Out of resources when opening file '/tmp/#sql_2768_0.MYI' (Errcode: 24 - Too many open files)

Anybody a idea?

Does this reply help @Approach ?

Thanks @matthieu,

It was a cronjob problem from my side. I changed the mysql version to 5.6 last days. In the mysql error log i can see many information…like this:

1804276 2015-11-06 00:35:06 10088 [ERROR] /usr/sbin/mysqld: Can’t open file: ‘./statistic_google/pageview_day.frm’ (errno: 24 - Too many open files)