[candu]

One problem with this is the "long tail" issue: in many applications, you have a highly active small minority of users, and any server assigned to enough of those users will be overloaded while other servers are underutilized. Since these are also (typically) your most excited / engaged users, this effectively penalizes user behaviors you'd rather encourage.

The other main problem is that it's not a consistent hash: if you grow the server pool, you typically need to reshard a lot of content.

(It's still useful in a pinch, but it helps to be aware of the tradeoffs.)