Database table cache_views_data is extreme large, what size is normal?
There is no normal size, it depends on your site, but I think that there's some error because this table grows exponentially.

My site was down because the size of this table. In my case, with a few views &amp; something like 1000 users this table was 29 Gigabits. I deleted it and then everything went back to normal.

I suggest you to keep an eye on the tables of your database, specifically this table.