On Thu, May 12, 2016 at 10:54 AM, Guru Shetty <g...@ovn.org> wrote: > >> I think you misunderstood - having one or more gateway per tenant does >> not make Transit LS better in flow scale. >> The size of a Transit LS subnet and management across Transit LSs is one >> the 5 issues I mentioned and it remains the same >> as do the other issues. >> >> Based on the example with 1000 HVs, 1000 tenants, 1000 HV/tenant, one >> distributed logical router per tenant >> spanning 1000 HVs, one gateway per tenant, we have a Transit LS with 1001 >> router type logical ports (1000 HVs + one gateway). >> >> Now, based on your previous assertion earlier: >> "If a user uses one gateway, a transit LS only gets connected by 2 >> routers. >> Other routers get their own transit LS." >> >> This translates: >> one Transit LS per tenant => 1000 Transit LS datapaths in total >> 1001 Transit LS logical ports per Transit LS => 1,001,000 Transit LS >> logical ports in total >> 1001 arp resolve flows per Transit LS => 1,001,000 flows just for arp >> resolve. >> Each Transit LS comes with many other flows: so we multiply that number >> of flows * 1000 Transit LSs = ? flows >> 1001 addresses per subnet per Transit LS; I suggested addresses should be >> reused across subnets, but when each subnet is large >> > > Re-reading. The above is a wrong conclusion making me believe that there > is a big disconnect. A subnet in transit LS has only 2 IP addresses (if it > is only one physical gateway). Every additional physical gateway can add > one additional IP address to the subnet (depending on whether the new > physical gateway has a gateway router added for that logical topology.). >
With respect to the IP address usage. I think a diagram would help especially the K8 case, which I had heard in other conversations may have a separate gateway on every HV ?. Hence, I would like to know what that means - i.e. were you thinking to run separate gateways routers on every HV for K8 ? With respect to the other questions, I think its best approach would be to ask direct questions so those direct questions get answered. 1) With 1000 HVs, 1000 HVs/tenant, 1 distributed router per tenant, you choose the number of gateways/tenant: a) How many Transit LS distributed datapaths are expected in total ? b) How many Transit LS logical ports are needed at the HV level ? what I mean by that is lets say we have one additional logical port at northd level and 1000 HVs then if we need to download that port to 1000 HVs, I consider that to be 1000 logical ports at the HV level because downloading and maintaining state across HVs at scale is more expensive than for a single hypervisor. c) How many Transit LS arp resolve entries at the HV level ? what I mean by that is lets say we have one additional arp resolve flow at northd level and 1000 HVs then if we need to download that arp resolve flow to 1000 HVs, I consider that to be 1000 flows at the HV level because downloading and maintaining state across multiple HVs is more expensive that a single hypervisor. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
