1. xOMB Incrementally scalable architecture for middleboxes Presenter : Donghwi Kim

2. Overview What is middlebox? Process, forward and modify traffic between source and destination. Routers and switches can also be classified as middleboxes xOMB is an active middle box Performs programmable traffic processing based on entire packet contents

3. 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

4. xOMB LBS Architecture

5. Design of xOMB Server Modules Pipelines

6. Example pipeline: HTTP

7. 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

8. 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.

9. Messages & Buffer Management

10. Message Reordering

11. Evaluation