We have a site under Magnento 2.1.0 CE and have been experiencing a strange issue. After being hit hard by traffic (normally hacking attempts or Asian spiders that ignore robots.txt), some pages on the frontend or backend lose their styling.
When we look at what comes back from the server, the page is started at the body tag - there is no <html> or <head> to be found, which is why there is no styling. Experimenting with clearing caches, it is clearing the layout cache that brings the pages back to normal.
There are no relevant errors when presenting these pages. 200 response and no exceptions except when Magento gets confused because some of the page is missing.
We have been using redis cache (just turned this off to see if it makes a difference) and the server setup is nginx 1.8, php 7.0.9 and mysql 5.6.
This problem does remind me of the cache corruption issue in Magento 1, but firstly one would hope this problem would not carry over into Magento 2 and secondly that the php error would have been fixed by v7.
UPDATE: It's worth noting that this problem seems to have gone away by 2.1.3. This isn't an "answer" as such, as it's possible people are stuck on 2.1.0 and would like to solve this.