Software Load Balancer for OpenFlow Complaint SDN architecture

Enhancing Load Balancer For OpenFlow Compliant

SDN Architecture MIT COLLEGE OF ENGINEERING BY- Pritesh Ranjan

Pankaj Pande Ramesh Oswal Zainab Qurani

Contents

• Introduction to SDN• Project idea• Load balancing methods• Our approach• Controller selection• Environmental setup• Reactive/Proactive approach• Partitioning algorithm• Transitioning algorithm• Questions

Packet Forwarding Hardware

App

App

App

Packet Forwarding Hardware

App

App

App

Hardware Packet Forwarding

App

App

App

Packet Forwarding Hardware

OperatingSystem

OperatingSystem

OperatingSystem

OperatingSystem

App

App

App

Network Operating System

App App App

INTRODUCTION TO SDN

1. Open Interface to HW (South Bound API)

3. Open API for business Applications (NorthBound API)

2. Operating System (controller Platforms)

Load BalancerSwitch

Project Idea

Transform into

The Plan

OpenFlow Compatible

Controller

Load Balancing Module

That’s it !

Our Approach

For Weighted Load Balancing ?

To ensure Connection Persistence ?

For non-uniform traffic pattern?

Partitioning Algorithm

Load Redistribution Algorithm

Transitioning Algorithm

Controller Selection

??

Coming Up Next

Environment Setup Setup a network with 10 hosts on 1 switch

Time Required ??

Setup a network with 100 hosts on 5 switches.

Time Required ??

Tired / Bored ??

Solution : “Mininet”

Switch

10.0.0.10 Port 2 LowSource Subnet Forward to Priority

Rule Table

Default Controller

h1 h2

Srcip=10.0.0.10 Srcip=10.0.0.20

s1

Mininet : Using Inbuilt Wrapper “mn”

Create Custom Network with own Scripts

Controller

Controller Design

To redirect traffic destined for “Service IP” to one of the backend replica servers A/c to assigned weighted load.

Network Design Decisions

Distributed or Centralized ?

Goal of the Application

Flow Based or Aggregated?

Reactive or Proactive?

Centralized

Both – Microflow and wildcard rules

Proactive

Match(exact & wildcard) Action Statistics

Match(exact & wildcard) Action Statistics

Match(exact & wildcard) Action Statistics

Match(exact & wildcard) Action Statistics

---------------

Srcip=10.0.23.23) Output port = 2 No. of Packets=10

Srcip=10.0.0.0/10Priority=Low Output port = 4 No. of bytes

Srcip=10.0.0.0/10Priority=High Send to controller No of received packets

Microflow rules

Wildcard rules

Rules/Flow Entries

Controller

Switch

Source Forward to PriorityRule Table

A R4 MediumB R2 High

R1

R2

R3

R4

Load Balancer

Reactive Approach

Drawback: High Setup time

Controller

Switch

Source Subnet Forward to PriorityRule Table

10.0.0.0/11 R4 Medium10.32.0.0/11 R2 High

R1

R2

R3

R4

Load Balancer

10.64.0.0/11 R1 Low

10.224.0.0/11 R4 Medium

Configuring switch

Table Generated

Proactive Approach

Drawback: Wildcard rules are

expensive

Implementation Details

AIM:

Reduce initial setup timeServers get load in proportion to the assigned weightsMinimum number of wildcard rules

APPROACH:

Proactively install wildcard rules to smaller sub-subnetsAssign each server some subnets according to weighted loadMinimization technique

Coming Up Next

Partitioning Algorithm

Partitioning AlgorithmDeciding the no of subnets:

Server R1Alpha = 2

Server R2Alpha = 3

Server R3Alpha = 1

Total alpha = 2 + 3 + 1 = 6

Nearest 2n = 8

Normalization Factor = 8/6 = 1.333

Weighted Load = 3

Weighted Load = 4

Weighted Load = 1

Weighted Load:R1 = 1.333 * 2 = 2.666 = 3 R2 = 1.333 * 3 = 3.999 = 4 R3 = 1.333 * 1 = 1.333 = 1

No of subnet = 3 + 4 + 1 = 8Partition The subnet into 8

subgroups

10.0.0.0/8

10.128.0.0/910.0.0.0/9

10.0.0.0/10 10.64.0.0/10 10.128.0.0/10 10.192.0.0/10

10.0.0.0/11 10.32.0.0/11

10.64.0.0/11 10.96.0.0/11

10.128.0.0/11 10.160.0.0/11

10.192.0.0/11 10.224.0.0/11

Server R1Weighted Load

= 3

Server R3WL = 1

Server R2Weighted Load = 4

Company Network

Partitioning Algorithm

000*

R1

001*

R1

010*

R1

011*

R2

100*

R2

101*

R2

110*

R2

111*

R3

0 1

0 1 0 1

0 1 0 1 0 1 0 1

/ 8

/ 9

/ 10

/ 11

Number of wild card rules = 8

Partitioning Algorithm – Contd.

Partitioning Algorithm - Analysis

Benefit :

Limitation :

Improvement :

Reduced initial setup timeMinimal involvement of controller

Too Much wildcard rules

Minimization technique

Coming Next

Dynamic Load redistribution

Coming Soon

For uniform client traffic pattern

000*

R1

001*

R1

010*

R1

011*

R2

100*

R2

101*

R2

110*

R2

111*

R3

Swap

011*

111*

Minimization Technique

000*

R1

001*

R1

010*

R1

111*

R2

100*

R2

101*

R2

110*

R2

011*

R3

1*

R2

00*

R1

Number of wild card rules = 4

Minimization Technique

Load Shift Operation

Situation:

Goal:

Conditions:

Solution:

Server R1 needs to be taken down for maintenance.

Traffic of R1 (old) should be allocated to R2 (New)

Ongoing connections should be continued with old server(R1)New connections should be forwarded to new server(R2)R1 can be taken down only when all the connections have expired.

Transitioning Algorithm

Subnet A

Subnet B

R1(Old)

R2(New)

Server R1 is to be taken down, Shift its load

To R2

Ok, let me check the connections

for SYN

Rule Table

Source Subnet Forward to Priority

A R1 Low

B R2 Low

Transitioning Algorithm

Subnet A

Subnet B

R1(Old)

R2(New)

Rule Table

Source Subnet Forward to Priority

A R1 Low

B R2 Low

1. Adds new flow entry2. Modify Old Flow Entry

R2

A Controller High

Rule Table

Source Subnet Forward to Priority

A R2 Low

B R2 Low

A Controller High

Transitioning Algorithm

IP=10.0.0.1Subnet A

Subnet B

R1(Old)

R2(New)

Add micro flow rule

Rule Table

Source Subnet Forward to Priority

A R2 Low

B R2 Low

A Controller High

SYN flag NOT SET

10.0.0.1 R1 Highest

Transitioning Algorithm

IP=10.0.0.1Subnet A

R1(Old)

R2(New)

Add micro flow rule

Rule Table

Source Subnet Forward to Priority

A R2 Low

B R2 Low

A Controller High

SYN flag SET

10.100.0.1 R2 Highest

IP=10.100.0.1Subnet A

Transitioning Algorithm

IP=10.0.0.1Subnet A

R1(Old)

R2(New)

Flow Entries get deleted after Idle time-out

Rule Table

Source Subnet Forward to Priority

A R2 Low

B R2 Low

A Controller High

10.100.0.1 R2 Highest

IP=10.100.0.1Subnet A

Now R1 can be taken down

Transitioning Algorithm

R1 (X=2)

R2 (X=2)

2*x

2*x

00*

01*

10*

11*

x

x

x

x

00* R101* R110* R211* R2

Uniform Client traffic pattern

Each subnet has same no of Connections Each server gets proportional no

of Connections (weighted Load)

R1 (X=2)

R2 (X=2)

2*x

2*x

00*

01*

10*

11*

2*x

1*x

1*x

0*x

00* R101* R110* R211* R2

Non-Uniform Client traffic pattern

Subnets have unequal no of requests Load gets unequally distributed

among servers

R1 (X=2)

R2(X=2)

3*x

1*x

00*

01*

10*

11*

2*x

x

x

0*x

00* R1

Overloaded Server

Underloaded Server

Read StatisticsFind over and underloaded serverShift appropriate load from over to under loaded server

01* R1

10* R2

11* R2

01* R2

2*x

2*x

Load Redistribution Algorithm

Project Demo: Videos

Topology Creation

Partitioning Algorithm- Video 1

Transitioning Algorithm

Load Redistribution Algorithm

Partitioning Algorithm- Video 2

Questions..??

THANK YOU….!!!

Topology

Extra slides

Comparative StudyParameter H/w Load Balancer POX S/w Load Balancer Our Solution

Methods IP Sticky

Round RobinCookie StickyWeighted Load

IP StickyRandom

IP StickyPersistent

Weighted load

Layer Layer 4Layer 7

Layer 4 Layer 4Layer 7

Server health Monitoring

PINGHTTP GET

ARP ARPPING

Speed Fast Slow Slow

Cost Costly Free Free

Switch

10.0.0.1 Port 2 LowSource Subnet Forward to Priority

Rule Table

Default Controller

Default Switch

h1h2

Srcip=10.0.0.1Srcip=10.0.0.2

s1

Controller

Switch

Source Subnet Forward to PriorityRule Table

10.0.0.0/11 R1 Low10.32.0.0/11 R1 Low

R1

R2

R3

R4

Load Balancer

10.64.0.0/11 R1 Low

10.224.0.0/11 R4 Medium

Configuring switch

Table Generated(No. of Wildcard rules 8)

Partitioning Algorithm (Flow Table)

Partitioning Algorithm (Cont.)

000*

R1

001*

R1

010*

R1

011*

R2

100*

R2

101*

R2

110*

R2

111*

R3

0 1

0 1 0 1

0 1 0 1 0 1 0 1

/ 8

/ 9

/ 10

/ 11

Number of wild card rules = 8Achieved Benefit- Reduced initial setup time. Drawbacks- Very large number of rules installed.Improvement-Minimization Techniques

Minimization Technique(Cont.)

000*

R1

001*

R1

010*

R1

011*

R2

100*

R2

101*

R2

110*

R2

111*

R3

Swap

011*

111*

Minimization Technique(Cont.)

000*

R1

001*

R1

010*

R1

111*

R2

100*

R2

101*

R2

110*

R2

011*

R3

1*

R2

00*

R1

Number of wild card rules = 4

Controller

Switch

Source Subnet Forward to PriorityRule Table

10.0.0.0/11 R1 Low10.64.0.0/11 R1 Low

R1

R2

R3

R4

Load Balancer

10.96.0.0/11 R2 Low10.128.0.0/9 R3 Low

Configuring switch

Table Generated

Minimization Technique (Flow Table)

Scapy• Scapy is a Python framework for crafting and

transmitting arbitrary packets

• Scapy also performs very well on a lot of other specific tasks that most other tools can’t handle, like sending invalid frames, injecting your own 802.11 frames

ARP

Replica R1

Replica R2

Replica R3

Replica R4

Replica R5

Source MAC: 00:00:00:00:00:01 Dest MAC: ff:ff:ff:ff:ff:ffSource IP: 10.24.24.24Dest IP :10.0.0.2

TCP/HTTP

Replica R1

Replica R2

Replica R3

Replica R4

Replica R5

Source IP: 10.24.24.24Dest IP :10.0.0.2Src Port:RandomDst Port :80Protocol:TCP

Source IP: 10.134.4.2Dest IP :10.0.0.2Src Port:RandomDst Port :80Protocol:TCP