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CloudNet 2013 An Efficient Flow Cache algorithm with Improved Fairness in Software-Defined Data Center Networks Bu Sung Lee 1, Renuga Kanagavelu 2 and.

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Presentation on theme: "CloudNet 2013 An Efficient Flow Cache algorithm with Improved Fairness in Software-Defined Data Center Networks Bu Sung Lee 1, Renuga Kanagavelu 2 and."— Presentation transcript:

1 CloudNet 2013 An Efficient Flow Cache algorithm with Improved Fairness in Software-Defined Data Center Networks Bu Sung Lee 1, Renuga Kanagavelu 2 and Khin Mi Mi Aung 2 1 Nanyang Technological University, Singapore 2 A-STAR (Agency for Science and Technology), Data Storage Institute, Singapore

2 CloudNet 2013 Changing scene in DC Data Center size has grown to a scale that we never imagine (http://storageservers.wordpress.com/2013/07/17/facts- and-stats-of-worlds-largest-data-centers/ ).http://storageservers.wordpress.com/2013/07/17/facts- and-stats-of-worlds-largest-data-centers/ –Google: 900,000 servers across 13 data centers –Amazon: 450,000 servers, in 7 locations Virtualisation. Changing Data Center Network traffic (North-South to East-West) Traffic Types : mice and elephant.

3 CloudNet 2013 Constraints Openflow switches flow table can hold up to 1500 entries. It is possible to increase TCAM entries, but it consumes lots of ASIC space, power and cost. Centralized controller

4 CloudNet 2013 Limitations of 3-tier network architecture AddressInterfaceTime 62-FE-F A3 19:32 7C-BA-B2-B :47 ……… Table size increases proportionally to the number of servers => Scalability issue Racks of servers Top of Rack Switches Aggregation Switches Core Switch … … … Interface 1 Interface 2 MAC Addr: 62-FE-F A3 MAC Addr: 7C-BA-B2-B Redundant paths are not used (due to STP) => Total bandwidth reduction issue Forwarding table: 4

5 CloudNet 2013 Traffic types 5

6 CloudNet 2013 Technology used Flow cache organised into separate buckets for elephant and mice. –Determine flow type by using 100 Mbytes in 5 second threshold. –Used the vLAN priority code bit (PCB) to indicate. –Uses dynamic index hashing. Cache replacement strategy –Uses Least Recently Used (LRU) 6

7 CloudNet 2013 Experimental set-up 7

8 Objective To propose a differential flow cache framework that achieves fairness and efficient cache maintenance with fast lookup and reduced cache miss ratio Motivation Openflow switches flow table can hold up to 1500 entries(This is too small when compared to the number of flows arriving at the switch) It is possible to increase TCAM entries, but it consumes lots of ASIC space, power (about 15 Watt/1 Mbit) and cost(US$350 for a 1M-bit chip). Centralized controller – Reduce the overload – Distributed framework The framework uses a hash-based placement and localized Least Recently Used (LRU)-based replacement mechanisms. Motivation

9 CloudNet 2013 Architecture

10 CloudNet 2013

11 Dynamic index Hashing

12 CloudNet 2013 Bucket Expansion

13 CloudNet 2013 Performance Evaluation Comparison of cache hit Ratio

14 CloudNet 2013 Performance Evaluation 14

15 CloudNet 2013 Performance Evaluation Look up Time

16 CloudNet 2013 Performance Evaluation

17 CloudNet 2013 DDR3 SDRAM 16bits DDR3 SDRAM 16bits DDR3 SDRAM 16bits Memory Memory Controller 64 bits (8Bytes) 4 Look-Aside Interface SHA - 1 Look up Update Drop Add entry Output Buffer Input Buffer Header Action Header Action SHA Value Cache architecture

18 CloudNet 2013 Conclusions Simple and effective means to address the overload on the controller Fast lookup Reduced cache miss ratio with LRU We have developed a NVRAM version of the cache for plugging into switches.

19 CloudNet 2013 Future work DC VM Placement strategy –Power aware –Network aware –Resilience Inter-domain Openflow Software defined everything 19


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