Abstraction of a failure free Software Defined Network (SDN Application)

Abstraction of a failure free Software Defined Network

(SDN Application)

Agenda



What and How of abstracting a failure free

Software Defined Network



The SDN Application (SDN App) architecture

1



Deep dive into the SDN App functionality



Demo

2



Performance reports and roadmap ahead



Q & A

All is Well in the Software Defined Network

 As-Is network

 Once flows are written to the network, SDN Controller is no more involved

 Data plane does traffic engineering based on the flows written

All is Well in the Software Defined Network

 Controller specific recovery logic

How are we recovering ?

 Congestion due to re-routed traffic ?

 Erstwhile failure recovery mechanism works for SDN ?  Pre-computed back-up

paths enough to provide resilience ?

Post recovery

Abstraction of a Failure free-SDN Network | Use-Case

Decouple failure

recovery and

application logic

Can we abstract a

Failure Free network

Enables recovery,

not overloading

Primary Controller

Implement a

SDN Application

Benchmarking

the SDN

Application

Performance

Results

SDN Application based on SDN Controller - OpenDaylight, applicable for

IP network (OpenVSwitch) and leverages emulator (mininet)

01

03 04

05 02

SDN Application - Record and Monitor

 Leverages OpenDaylight Northbound APIs

 Scripts enables operational of a programmable interface

State-full workflow manager

 Record mode - Records events

 Port monitor - Topology change detection  Replay mode - Triggers Shadow controller  Topology re-compute

 Network reconfiguration

Network creation and replay

 Leverages OpenDaylight Northbound APIs

 Additional scripts to get flows and compute delta flows (Shadow network vs. Primary network)

Challenges

 Emulated network creation - fast and efficient  Replay should be quick and efficient

 Current support for IP networks, Multi-layer SDN to be investigated

Performance

 Scalability tests done till 400 Nodes (targeted to be extended to 5000 Nodes)  Replay of over 40k packets at rate of 2k/sec

Abstraction of a Failure free-SDN Network | Architecture

or Topology Service Workflow Manager Packet/Flow Mod Logger

Packet Replay Flow Capture

Recovery

Emulated Network

(mininet)

Software Defined Network

(Live Network) Host Host Pri mar y Con tr oll

er Northbound API Northbound API

Rest APIs Cap

tur e flow s (sc rip t) Interface

Agenda



What and How of abstracting a failure free

Software Defined Network



The SDN Application (SDN App) architecture

1



Deep dive into the SDN App functionality



Demo

2



Performance reports and roadmap ahead



Q & A

 Leverage Packet Logger: IDataPacketService (Interface: IListenDataPacket) to capture PacketIn message

 SDN App writes the PacketIn message into the database

 Capture Flow-Mod message using Flow Logger: ForwardingRulesManager Service ( Interface: IForwardingRulesManager)

 Associate the flow message with the PacketIn messages and store in database

 Segregate the stored PacketIn messages as

– Primary events: Packets at ingress ports using NodeConnector information and ISwitchManager API

– Implied events: All other events caused by same packet through network

Abstraction of a Failure free-SDN Network | The Components

Database Ne tw or k Monit

or Topology Service Workflow Manager Packet/Flow Mod Logger

Packet Replay Flow Capture

 Monitors Primary network using Topology Northbound API (gets topology information like edges information etc.)

 Uses HostTracker Northbound API (To get active host's information from primary network): GET operation

 On topology churn detection (ex. Node OOS), triggers Workflow manager to initiate Shadow network

 Maintains mapping of node connector id and ports on primary and shadow network (through a script)

 Triggers Packet replay module via Workflow Manager

Abstraction of a Failure free-SDN Network | The Components

Database Ne tw or k Monit

or Topology Service Workflow Manager Packet/Flow Mod Logger

Packet Replay Flow Capture

Recovery

 Provides APIs to IO functions PacketIn/FlowMod/mapping onto database

 Maintains state machine for Record, Monitor, Replay & Re-compute and Reconfigure

 Creates the shadow network without the fault-Node - leverages mininet emulator (IP Networks only)

 As part of reconfigure calculates delta-flows (Primary network flows - Shadow network flows)

 Write delta flows to primary network using FlowProgrammer Northbound API

 Post completion of reconfiguration responsible for Database and Shadow network cleanup

Abstraction of a Failure free-SDN Network | The Components

Database Ne tw or k Monit

or Topology Service Workflow Manager Packet/Flow Mod Logger

Packet Replay Flow Capture

 Retrieves the primary packets from Database

 Injects the Packets into ingress ports of the Shadow network - DataPacketService : To create packet from database and replay it over shadow network.

Abstraction of a Failure free-SDN Network | The Components

Database Ne tw or k Monit

or Topology Service Workflow Manager Packet/Flow Mod Logger

Packet Replay Flow Capture

Recovery

 Captures the Flow-MOD messages to the Shadow network - FlowProgrammer Northbound API (To get flows from shadow network and put them onto primary network) : GET and PUT operations.

 Triggers Workflow Manager with the captured flows

Abstraction of a Failure free-SDN Network | The Logic flow

Primary Network

Topology

changes detected Record mode

Recovery mode Record all PacketIn messages Record all Flows

Filter primary and implied events

Associate the flow message with the PacketIn messages Database Workflow Manager Rebuild the network topology without the affected Node Retrieve PacketIn messages Replay Shadow Network Capture Flows Network Monitoring NO YES

Batch process clean up expired flow 1 2 3 4 5 6 7 8 9 10 ₁₁ 12 13 14 15

Abstraction of a Failure free-SDN Network | Functionality (recap)

01

02

03

04

Records events to Controller

 PacketIn messages coming from switches

 FlowMod events in response to PacketIn messages

Network state re-computation

 Detect network topology changes( Switch/link down/up)

 Start copy of controller( say shadow controller)

 Create emulated network (say shadow network)

 Replay recorded events to emulated environment as per

order in primary network

Network creation and replay optimization

 Filter events coming from network edges.

 Expire events which are no longer required

 Parallel replay of independent events

Network reconfiguration

 Compute delta rules between shadow and

DEMO NOW

Agenda



What and How of abstracting a failure free

Software Defined Network



The SDN Application (SDN App) architecture

1



Deep dive into the SDN App functionality



Demo

2



Performance reports and roadmap ahead



Q & A

Results and Roadmap Ahead

Roadmap ahead

Enhance SDN App to OpenDaylight MD-SAL

Approach to Alarm storms Distributed setup of Primary/Shadow controllers

Optimization - Pre-Set shadow network

Proof of Concept – Setup and results

 Ubuntu 14.04, 4GB, Intel dual-core

 Co-resident OpenDaylight controller (Primary and Shadow)

 Co-resident SDN network (primary and shadow network)

 Scalability setup

 AFRO SDN Application scaled for 100-400 Nodes