So the issue happens with "pinuts" site, sorry just trying to catch up.
Have you tried switching themes?
You also said the spike doesn't happen same time each day, it varies.
I'm wondering if there's an area on your ecommerce site, where if ran, it reads so much data it actually kills all available resources ending in a overall crash of MYSQL. Seen it happen before, just bad coded in function but that also was with 10k products, how many do you have?
