This document discusses Open vSwitch (OVS) and how using Data Plane Development Kit (DPDK) can improve its performance. It notes that with standard OVS, there are many components between a virtual machine and physical networking that cause scalability and performance issues due to context switches. OVS-DPDK addresses this by using polling, hugepages, pinned CPUs, and userspace I/O to bypass the kernel and reduce overhead. The document shows that using DPDK can increase OVS throughput by over 8x and reduce latency by 30-37% compared to standard OVS.

1. OVS
v
OVS-DPDK

2. ABOUT ME
Md Safiyat Reza
Open-source enthusiast
Delving into cloud.
safiyat
@reza_safiyat
reza.safiyat@acm.org

3. What is OVS?

6. VM
virtio driver
ping 8.8.8.8
OK, wait a sec

7. virtio driver
QEMU virtio
backend
VM wants to ping
8.8.8.8
OK, wait a sec

8. QEMU virtio
backend
tap device
Hey there, ping
8.8.8.8 for me
OK, gimme a
moment

9. tap device
Kernel
Here is an ICMP
packet. Do what you
do best.
Get back to you
in a jiffy

11. Why OVS-DPDK?

12. • Lots of components between VM and physical networking infrastructure
causing scalability issues and performance degradation.
• Context switches

14. • Polling
• Hugepages
• Pinned CPUs
• Userspace IO

17. • Kernel flows are basically a cache
• OVS performs very well so long as the packets hit this cache
• Default flow timeout is 10 seconds.
• Most of the overhead here is in copying packets in the userspace and context switching.

18. Standard OVS OVS-DPDK
Gbps 1.159 9.9
MPPS 1.72 14.85
Throughput
• Xeon E5-2643@3.5 GHz
• Intel 82599EB
• Linux Kernel 3.17

19. Standard OVS OVS-DPDK Difference
TCP 46 33 ~ 30%
UDP 51 32 ~ 37%
Latency
• Xeon E5-2643@3.5 GHz
• Intel 82599EB
• Linux Kernel 3.17

20. Thank you!