[user5994461]

They are different algorithm for different purpose.

Consistent hashing is used to always attach a request to the same host. It's the opposite of load balancing.

Load balancing algorithms (least connection, business, etc...) are used to distribute requests across servers as well as possible to maximize performances.

[pas]

Usually both properties are desirable .. up to a point.

You want to minimize load on all servers, but you also want to pack things up efficiently (so minimize operational costs), but of course you want the benefits of caching, so you want requests from a sessions to land on the same node/server/box.

Basically a multi-dimensional optimization problem. Completely solvable with constraints. Let the business people decide what's more important, latency or throughput or low cost of operations.