Tối ưu hiệu năng đáp ứng các yêu cầu của hệ thống 4G core

1. Cloud for 4G Core
4G Core Introduction1
Performance Problems2
Next Plan3

3. 4G Core Network & NFV

4. OCS Requirement
Average Latency < 2ms
200.000 Request per
seconds
80M customers
Hardware cost < 0.1$ /sub
Uptime 99.999%

5. EPC Requirement
Avarage Latency < 2ms
>100k Request per seconds
1-2M customers
Throughput: 300Gbs
Offline tracing

6. Objective
Cloud design
Optimization &
Simulation
• VM design.
• VN network
Design
• Compute.
• Network.
• Storage.
• Software
INPUT
Bare metal design
Requirements
OUTPUT
Number VM
VM flavor & configuration
VN configuration

7. Openstack for 4g core
• Openstack: Queens
• Hypervisor: KVM
• Network: OpenvSwitch
• Storage: CEPH
• Hardware: x86_64
• OS: Redhat

8. 2.Performance Issues
• Compute processing
- CPU
- Memory
• Packet processing
- Throughtput
- Latency

9. Compute resources
• High rate cpu usage
- High cpu by workload(VM > Host 15%)
• Competing for cpu resources
- CPU Steal Time (%st)

10. Solution
• CPU pinning: VM pinned to
dedicated CPU cores
- Numa
- Hyperthreads
- Hugepages

11. NUMA
• NUMA awareness Scheduling
- Non-Uniform Memory Access
- Each CPU has it own memory(fast)
- Other memory can accessed indirectly(slower)

12. HyperThreads
• Hyper Threading
• CPU Caching

13. Hugepages
• Hugepages:
- Allocate by NUMA
- No swapping

14. Conclusion
• Result: ~ 95% physical
• Advantages:
- Isolate VM resources
- Optimal using resources%
• Disadvantages:
- Expensive
- Inflexiable

15. Network Issues
• Latency
- Controller plane apps
• Throughput
- Data plane apps
• Quality
- Packet loss

16. OpenvSwitch
• Multilayer virtual switch
• Feature: VLAN, STP, LACP,
Mirroring, Flow, Tunnel,
QoS

17. OpenvSwitch Datapath
• Datapath is the forwarding plane of OVS.
- System datapath(default)
- Userspace datapath(netdev-dpdk)

18. DPDK(Data Plane Development Kit)
• DPDK: accelerate packet processing workloads
running on a wide variety of CPU architectures
EAL: Environment Abstraction
Managing Queues: rte_ring
Memory Management: rte_mempool
Buffer Management: rte_mbuf
Other Libraries

19. OVS-DPDK
• Benefit:
- Bypass kernel
- Batch packets handling
- …

20. OVS-DPDK
• Additional:
- Vhostuser
- PMD Driver
- PMD Thread
- …

21. PMD Thread performance
• PMD Threads:
- Multi PMD threads
- CPU pinning (Poll mode)
- Use vhostuser multi queue
Packet size 64
Physical NIC 10GB
PMDs 4
Physical 15Mpps
VM(Linux socket) 200Kpps
Latency
https://software.intel.com/content/www/us/en/develop/articles/configure-vhost-user-multiqueue-for-ovs-with-
dpdk.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+ISNMain+%28Intel+Developer+Zone+Articles+Feed%29

22. Packet loss
• Issue:
- Packets loss while PMD threads low usage rate
- VM process packet not fast enough
• Solutions:
- Increase tx/rx queues size
- Using DPDK app in VM

23. Dataplane throughput
• EPC throughput: 36Gbs/VM
• OVS-DPDK:
- Throughput not enough
- Too many resources for OVS
• Solution:
- PCI Passthrough ???
- SR-IOV

24. SRIOV for Data plane
• Physical Function
• Virtual Function:
- “lightweight” PCI
Advantages:
- Optimal resources
- Minimize overhead, bottlenecks
- DMA to VM memory
http://www.intel.com/content/dam/doc/application-note/pci-sig-sr-iov-primer-sr-iov-technology-paper.pdf

25. PCI Locality Mapping
• PCI map to NUMA
• VM map to NUMA
PCI and VM in same NUMA is better

26. 3. Plan
OVS-DPDK Offload
Smart NIC.
SDN.
Cloud for 5G.
Container.

27. Thankyou!