xOMBIncrementally scalable architecture for middleboxes

Presenter : Donghwi Kim

Overview

• What is middlebox?• Process, forward and modify traffic between source and

destination.• Routers and switches can also be classified as middle-

boxes

• xOMB is an active middle box• Performs programmable traffic processing based on en-

tire packet contents

Load Balancing Switches

• Although xOMB design is for general middlebox, we will examine it with load balancing switch scenario.

• LBS with xOMB• Packet-payload granularity• Additional functionalities:

• Re-writing HTTP 1.0 requests as 1.1• Connection collapsing

xOMB LBS Architecture

Design of xOMB Server

• Modules• Pipelines

Example pipeline: HTTP

Control Plane

• Membership• No manual configuration for adding or removing servers• The controller assigns every middlebox a set of servers

to monitor

• Monitoring• Each middlebox collects load information from a set of

servers assigned by controller

• Failure Detector• Each middlebox pings to their monitored servers

Design Discussion

• Advantages of callback(Typical programmable middlebox)• Straightforward to implement simple protocol-specific handling

• Advantages of modular pipelines(xOMB)• Asynchronous modules allow messages processing to perform RPCs to

retrieve or store state over the network• Pipelines are more flexible because they are not limited to a fixed set of

protocols or callbacks• xOMB pipelines elegantly allow modules to pass arbitrary per-message

state to other modules (message metadata).• xOMB pipelines are potentially more efficient, because parsing modules

only need to parse minimal amount of bytes.

Messages & Buffer Man-agement

Message Reordering

Evaluation

Evaluation

Evaluation

Evaluation