http://redhatstackblog.redhat.com/2016/02/10/boosting-the-nfv-datapath-with-rhel-openstack-platform/
NFV keywords for Linux networking
Linux, QEMU, KVM, Open vSwitch, DPDK, libvirt, OpenStack
open vswitch + DPDK
Starting with the upcoming RHEL OpenStack Platform 8 release, DPDK-accelerated Open vSwitch is expected to be available for customers and partners as a Technology Preview feature based on the work done in upstream OVS 2.4.
SR-IOV, as previously described, is very tight to the physical NIC, resulting in a lack of software abstraction on the hypervisor side. DPDK-accelerated OVS has the promise to fix that by offering the “best of both worlds”: performance on one hand, and flexibility and programmability through the virtualization layer on the other.
DPDK is for two parts
NFV keywords for Linux networking
Linux, QEMU, KVM, Open vSwitch, DPDK, libvirt, OpenStack
- Direct hardware access : done by the NIC hardware and is not visible to the Compute layer.
- firewall filtering (OpenStack security-groups) or live migration are currently not available when using SR-IOV
- Using a virtual switch
- Standard OVS is built out of three main components:
- ovs-vswitchd – a user-space daemon that implements the switch logic
- kernel module (fast path) – that processes received frames based on a lookup table
- ovsdb-server – a database server that ovs-vswitchd queries to obtain its configuration. External clients can talk to ovsdb-server using OVSDB protocol
- The Data Plane Development Kit (DPDK) consists of a set of libraries and drivers for fast packet processing. It is designed to run mostly in user-space
- One of the key concepts of DPDK, compared to the kernel networking stack, is the use of Poll Mode Drivers (PMDs). Instead of using an interrupt-based system, or context switching between the kernel-space and user-space, which disturbs the CPU anytime a new frame is coming, PMDs use polling approach: they are continuously scanning the NIC to see whether frames arrived or not. DPDK applications no longer communicate with the Linux kernel networking stack.DPDK helps to bypass the kernel network stack in order to deliver high performance.
open vswitch + DPDK
Starting with the upcoming RHEL OpenStack Platform 8 release, DPDK-accelerated Open vSwitch is expected to be available for customers and partners as a Technology Preview feature based on the work done in upstream OVS 2.4.
SR-IOV, as previously described, is very tight to the physical NIC, resulting in a lack of software abstraction on the hypervisor side. DPDK-accelerated OVS has the promise to fix that by offering the “best of both worlds”: performance on one hand, and flexibility and programmability through the virtualization layer on the other.
DPDK is for two parts
- DPDK enabled applications, or VNFs, written on top of RHEL as a guest operating system. Here we are talking about Network Functions that are taking advantage of DPDK as opposed to the standard kernel networking stack for enhanced performance.
- DPDK-accelerated Open vSwitch, running within RHEL OpenStack Platform Compute nodes (the hypervisors). Here it is all about boosting the performance of OVS and allowing for faster connectivity between VNFs.
if you want to run DPDK-accelerated OVS in the Compute node, you do not necessarily have to run DPDK-enabled applications in the VNFs that plug into it.
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