Please find the FS for this proposal at below link. I will be sending out a different proposal covering the enhancements called out in the FS.
https://cwiki.apache.org/confluence/display/CLOUDSTACK/Region+level+VPC+and +guest+network+spanning+multiple+zones On 19/12/13 5:54 PM, "Murali Reddy" <murali.re...@citrix.com> wrote: >I would like to propose two networking models enhancements for ACS 4.4 >release that will enable building highly available applications. Currently >VPC in CloudStack is a zone level entity. So tiers with in the VPC are >confined to the zone to which VPC belongs. For an application deployed in >current model of VPC failure of the zone is a single point of failure. It >is desirable to make VPC a region level entity, where tiers in the VPC can >be created in different zones of the region. When tiers can be created in >different zones, application hosted in VPC can be architected to be highly >available masking zone failures by having redundant tiers in different >zones. While it may be seen as natural extension, there are fundamental >limitations with VLAN/traditional L2 based networking due to which >realizing it would be non-trivial or require special solutions [1]. >Overlay networks [2] in the context of SDN & network virtualization >provides a way to build networks that are abstracted from >physical/underlay network. An overlay network is typically built with >tunnels across edge(vSwitch's in hypervisor) and core is plain L3 network. >With requirement that L3 connectivity across zones and tunnels can be >established across the zones, an overlay network that spans multiple zones >is easily realized. > >Given the range of SDN controllers that are integrated with CS, goal of >this proposal is to leverage advances in SDN & network virtualization >introduce below generic notions into CS. > >- an advanced zone isolated network that can span multiple zones >- a region level VPC where tiers belong to different zones. > >I have opened bugs [3],[4] to track these two enhancements. As part of the >effort I would like to extend the current OVS plug-in (that builds overlay >network with GRE tunnels) to realise these two use-cases. I have opened >bug [5] to track this enhancement. > >As long as we establish tunnels across the zones, we can have overlay >networks that are functional, but would be inefficient in handling >east-west traffic [6] and BUM traffic. While the problems exist in the >overlay networks that are confined to a zone as well, they are compounded >when the network spans multiple zones resulting in high cross-zone >east-west traffic. I would be sending out a complementary proposal to >introduce distributed routing and ACL's for east-west traffic and ARP >localisation that will allow only legitimate cross zone east-west traffic. > >I will send out a functional specification with detailed requirements, >assumptions, limitation etc once I make progress with these enhancements. >Please share any feedback and comments. > >[1] >http://www.networkworld.com/news/tech/2010/090310-layer2-data-center-inter >c >onnect.html >[2] >http://etherealmind.com/introduction-to-how-overlay-networking-and-tunnel- >f >abrics-work/ >[3] https://issues.apache.org/jira/browse/CLOUDSTACK-5567 >[4] https://issues.apache.org/jira/browse/CLOUDSTACK-5568 >[5] https://issues.apache.org/jira/browse/CLOUDSTACK-5569 >[6] >http://blog.ipspace.net/2011/02/traffic-trombone-what-it-is-and-how-you.ht >m >l > >
