On 6/15/20 12:56 AM, Yi Yang (杨燚)-云服务集团 wrote: > My next hops are final real servers but not load balancers, say we sets > maximum number of servers to 64, but next hop entry is added or removed > dynamically, we are unlikely to know them beforehand. I can't understand how > user space can attain consistent distribution without in-kernel consistent > hashing, can you show how ip route cmds can attain this? >
I do not see how consistent hashing can be done in the kernel without affecting performance, and a second problem is having it do the right thing for all use cases. That said, feel free to try to implement it. > I find routing cache can help fix this issue, if a flow has been routed to a > real server, then its route has been cached, so packets in this flow should > hit routing cache by fib_lookup, so this can make sure it can be always > routed to right server, as far as the result is concerned, it is equivalent > to consistent hashing. > route cache is invalidated anytime there is a change to the FIB.
