Exactly how the routes get steered to servers can vary (static routes with track objects, OSPF or BGP on the server), but the basic idea of using network gear to ECMP traffic between servers is, if not ancient, pretty common.
I suspect there's something novel in control plane or hashing used to steer ECMP but I didn't see anything about that in the article.
Well, it's "not new" in the sense that this system's been running google.com for about 8 years now ;)
This is just the first time that we've published how it works.
You still lose some connections when an LB fails, but only the ones going through the failed LB. Unrelated flows to other LBs are not impacted.
We've got multiple customers doing variants of the LB architecture Google talks about here.
Resilient hashing means that only flows going to the dead LB will get rehashed to other LBs. Those flows would break anyway, but the remaining flows are OK.
in such cases, only consistent hashing or maglev hashing might be the only option.