> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Kamraan Nasim > Sent: Thursday, November 13, 2014 6:30 PM > To: dev at dpdk.org > Cc: Yuanzhang Hu > Subject: [dpdk-dev] Load-balancing position field in DPDK load_balancer > sample app vs. Hash table > > 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?
If you have a NIC that is capable to do HW hash computation, then you can do your load balancing based on that value. Let say ixgbe/igb/i40e NICs can calculate RSS hash value based on different combinations of dst/src Ips, dst/src ports. This value can be stored inside mbuf for each RX packet by PMD RX function. Then you can do: worker_id = mbuf->hash.rss % n_workersl That might to provide better balancing then using just one byte value, plus should be a bit faster, as in that case your balancer code don't need to touch packet's data. Konstantin > > > --Kam
