Presentation on theme: "Modular Layer 2 In OpenStack Neutron Robert Kukura, Red Hat Kyle Mestery, Cisco."— Presentation transcript:
Modular Layer 2 In OpenStack Neutron Robert Kukura, Red Hat Kyle Mestery, Cisco
1.I’ve heard the Open vSwitch and Linuxbridge Neutron Plugins are being deprecated. 2.I’ve heard ML2 does some cool stuff! 3.I don’t know what ML2 is but want to learn about it and what it provides.
What is Modular Layer 2? A new Neutron core plugin in Havana Modular o Drivers for layer 2 network types and mechanisms - interface with agents, hardware, controllers,... o Service plugins and their drivers for layer 3+ Works with existing L2 agents o openvswitch o linuxbridge o hyperv Deprecates existing monolithic plugins o openvswitch o linuxbridge
Motivations For a Modular Layer 2 Plugin
Before Modular Layer 2... Neutron Server Open vSwitch Plugin OR Neutron Server Linuxbridge Plugin OR...
Before Modular Layer 2... Neutron Server Vendor X Plugin I want to write a Neutron Plugin. But I have to duplicate a lot of DB, segmentation, etc. work. What a pain. :(
ML2 Use Cases Replace existing monolithic plugins o Eliminate redundant code o Reduce development & maintenance effort New features o Top-of-Rack switch control o Avoid tunnel flooding via L2 population o Many more to come... Heterogeneous deployments o Specialized hypervisor nodes with distinct network mechanisms o Integrate *aaS appliances o Roll new technologies into existing deployments
Modular Layer 2 Architecture
The Modular Layer 2 (ML2) Plugin is a framework allowing OpenStack Neutron to simultaneously utilize the variety of layer 2 networking technologies found in complex real-world data centers.
What’s Similar? ML2 is functionally a superset of the monolithic openvswitch, linuxbridge, and hyperv plugins: Based on NeutronDBPluginV2 Models networks in terms of provider attributes RPC interface to L2 agents Extension APIs
What’s Different? ML2 introduces several innovations to achieve its goals: Cleanly separates management of network types from the mechanisms for accessing those networks o Makes types and mechanisms pluggable via drivers o Allows multiple mechanism drivers to access same network simultaneously o Optional features packaged as mechanism drivers Supports multi-segment networks Flexible port binding L3 router extension integrated as a service plugin
ML2 Architecture Diagram Neutron Server ML2 Plugin Type ManagerMechanism Manager API Extensions GRE TypeDriver Arista VLAN TypeDriver VXLAN TypeDriver Cisco Nexus Hyper-V L2 Population Linuxbridge Open vSwitch Tail-F NCS
Multi-Segment Networks VXLAN 123567 physnet1 VLAN 37physnet2 VLAN 413 VM 1VM 2VM 3 ●Created via multi-provider API extension ●Segments bridged administratively (for now) ●Ports associated with network, not specific segment ●Ports bound automatically to segment with connectivity
Port Binding Determines values for port’s binding:vif_type and binding:capabilities attributes and selects segment Occurs when binding:host_id set on port or existing valid binding ML2 plugin calls bind_port() on registered MechanismDrivers, in order listed in config, until one succeeds or all have been tried Driver determines if it can bind based on: o context.network.network_segments o context.current[‘binding:host_id’] o context.host_agents() For L2 agent drivers, binding requires live L2 agent on port’s host that: o Supports the network_type of a segment of the port’s network o Has a mapping for that segment’s physical_network if applicable If it can bind the port, driver calls context.set_binding() with binding details If no driver succeeds, port’s binding:vif_type set to BINDING_FAILED class PortContext(object): @abstractproperty def current(self): pass @abstractproperty def original(self): pass @abstractproperty def network(self): pass @abstractproperty def bound_segment(self): pass @abstractmethod def host_agents(self, agent_type): pass @abstractmethod def set_binding(self, segment_id, vif_type, cap_port_filter): pass
Type Drivers in Havana The following are supported segmentation types in ML2 for the Havana release: ●local ●flat ●VLAN ●GRE ●VXLAN
Mechanism Drivers in Havana The following ML2 MechanismDrivers exist in Havana: ●Arista ●Cisco Nexus ●Hyper-V Agent ●L2 Population ●Linuxbridge Agent ●Open vSwitch Agent ●Tail-f NCS
Before ML2 L2 Population MechanismDriver Host 1 Host 2 Host 3Host 4 Host 1 VM A VM GVM EVM D VM B VM C VM F VM H VM I “VM A” wants to talk to “VM G.” “VM A” sends a broadcast packet, which is replicated to the entire tunnel mesh.
With ML2 L2 Population MechanismDriver Host 1 Host 2 Host 3Host 4 Host 1 VM A VM GVM EVM D VM B VM C VM F VM H VM I The ARP request from “VM A” for “VM G” is intercepted and answered using a pre-populated neighbor entry. Proxy Arp Traffic from “VM A” to “VM G” is encapsulated and sent to “Host 4” according to the bridge forwarding table entry.
Modular Layer 2 Futures
ML2 Futures: Deprecation Items The future of the Open vSwitch and Linuxbridge plugins o These are planned for deprecation in Icehouse o ML2 supports all their functionality o ML2 works with the existing OVS and Linuxbrige agents o No new features being added in Icehouse to OVS and Linuxbridge plugins Migration Tool being developed
Plugin vs. ML2 MechanismDriver? Advantages of writing an ML2 Driver instead of a new monolithic plugin o Much less code to write (or clone) and maintain o New neutron features supported as they are added o Support for heterogeneous deployments Vendors integrating new plugins should consider an ML2 Driver instead o Existing plugins may want to migrate to ML2 as well
ML2 With Current Agents Neutron Server ML2 Plugin Host A Linuxbridge Agent Host B Hyper-V Agent Host C Open vSwitch Agent Host D Open vSwitch Agent API Network ●Existing ML2 Plugin works with existing agents ●Separate agents for Linuxbridge, Open vSwitch, and Hyper-V
ML2 With Modular L2 Agent Neutron Server ML2 Plugin Host A Modular Agent Host B Modular Agent Host C Modular Agent Host D Modular Agent API Network ●Future direction is to combine Open Source Agents ●Have a single agent which can support Linuxbridge and Open vSwitch ●Pluggable drivers for additional vSwitches, Infiniband, SR-IOV,...
What the Demo Will Show ●ML2 running with multiple MechanismDrivers ○ openvswitch ○ cisco_nexus ●Booting multiple VMs on multiple compute hosts ●Hosts are running Fedora ●Configuration of VLANs across both virtual and physical infrastructure
ML2 Demo Setup Host 1Host 2 Cisco Nexus Switch eth2/1eth2/2 eth2 nova computenova api... neutron serverneutron ovs agent neutron dhcpneutron l3 agent nova compute neutron ovs agent eth2 br-eth2 br-int br-eth2 br-int vm1 VLAN is added on the VIF for VM1 and also on the br-eth2 ports by the ML2 OVS MechanismDriver. The ML2 Cisco Nexus MechanismDriver trunks the VLAN on eth2/1. vm2 VLAN is added on the VIF for VM2 and also on the br-eth2 ports by the ML2 OVS MechanismDriver. The ML2 Cisco Nexus MechanismDriver trunks the VLAN on eth2/2. VM1 can ping VM2 … we’ve successfully completed the standard network test.