From the reading of the article, it sounds like much of their problems were related to several upgrades of Ceph having happened, and possibly also an ABI incomp

From the reading of the article, it sounds like much of their problems were related to several upgrades of Ceph having happened, and possibly also an ABI incompatible libstdc++ update rolling out. Probably not the cause of your RHEL 7 issues, since it is a much more conservative release. It sounds to me like the choice of Gentoo was at least partially responsible for that 5 day outage. With RHEL/CentOS, it's pretty good about keeping things stable from a software version perspective. The downside is when you really do need (or just plain really want) newer versions of software. But at least then you can make the conscious decision to manually maintain a few packages, while the rest of the core stays stable. I won't run anything but an LTS release in production. People always say "Well <my favorite distro> has release cycles every 2 years, and upgrading your systems that often should be fine." But I've been involved in OS upgrades that require 6+ months to do, and not infrequently. Most reasonably complex services (in my experience) take man-months of effort to go from, say, 12.04 to 16.04. Start having 3 or 4 such services, and non-upgrade work that needs to be done, and you start running out of time in a 2 year release cycle to complete updates.