Sudden blank page, with deep sql error

Hi, suddenly got a blank page on www.dev.tv I nor my customer had modified anything. In my templates, I can write static text but each time I write

{exp:channel:entries channel="..." }

tag I got blank page.

Don’t know why but sometimes I got this sql error

Error Number: 2013

Lost connection to MySQL server during query

SELECT `field_id`, `field_type`, `field_fmt`, `field_name`, `site_id`, `field_settings` FROM (`exp_channel_fields`)

Filename: libraries/api/Api_channel_fields.php

Line Number: 150

I would love it simply comes from my host having change PHP config…

Thanks, Sylvain.