The buckets, in the context of hash maps, are typically lists. Either arrays or linked lists. They're used to store the key-value pairs. Some load balancers do

The buckets, in the context of hash maps, are typically lists. Either arrays or linked lists. They're used to store the key-value pairs. Some load balancers do use hashing in much the same way hash maps do. Usually they'll take a combination of: source IP, source port, destination IP, destination port, and hash it. They'll then use that hash to pick a server. The practical impact of this is that each user always gets mapped to the same server. This is typically called "session sticky load balancing" because it means session information about that user can live on the server, safe in the knowledge that the user will always end up on that server and not get routed to any others.