On Thu, Nov 13, 2014 at 01:29:32PM -0500, Kamraan Nasim wrote: > Hello, > > So i've borrowed some code from the DPDK Load balancer sample application, > specifically the load balancing position(byte 29th) to determine which > worker lcore to forward the packet to. > > The idea is that flow affinity should be maintained and all packets from > the same flow would have the same checksum/5-tuple value > > worker_id = packet[load_balancing_field] % n_workers > > Question is that how reliable is this load balancing position? I am tempted > to use Hash tables but I think this position based mechanism may be faster. > > How have people's experience with this been in general? >
Using a modulus "%" operation will be far, far faster than doing a hash table lookup, though obviously it is not as flexible. [If you have a power-of-two number of workers, you can replace the "%" by "&", if you like to shave off another few cycles]. As for reliability, I'm afraid it depends entirely on your application and what field you pick as to whether it works for load balancing or not. /Bruce
