1. Communication Needs in Agile Computing Environments Michael Ernst, BNL ATLAS Distributed Computing Technical Interchange Meeting University of Tokyo May 15, 2013

2. The Role of Networking in Clouds As an information service the Internet treats the network as a transparent partner With the Cloud, user applications reside in and become part of the cloud Data Center has to be made Cloud-specific Should the WAN also be a resource in the Cloud? –Since Networks create the Cloud, managing the Interplay between all components is key to Cloud efficiency and success

3. Networking in a Virtualized Computing Environment Virtualization and mobility are driving what we call “Cloud Networking” –Different than enterprise networking –Needs to be built of a strong S/W foundation Centrally manage cloud and assign resources Enterprise is about connectivity, cloud & SDN is about optimizing applications Disruption requires new kind of S/W answer –No more one physical server w/ one connection –Thousands of VMs instead –Storage no longer SAN, Hadoop clusters –Core count increasing – millions of cores in future  With such change, network & I/O is bottleneck

4. Cloud Principles User joins Community the Cloud creates –Issue of multi-tenancy at the Network level as much as at CPU/server, DB levels –Shared resources must be shared in a way that applications from different users don’t interfere –Resources have to be partitioned so they are private and secure While IP & Ethernet have virtual network capability, they are limited in terms of number of tenants and how isolated a tenant is

5. Effects of Networking on Cloud Environments Network Latency could be a cloud killer –Cloud offers benefits of scalability & flexibility but w/o enough network capacity benefits are small Shifting workloads off-premises to clouds burdens network between cloud and our own data centers –Applications may suffer from poor performance –Network monitoring to understand network needs  When considering adding cloud resources network demands must be part of the plan  I.e. WAN b/w remains one of least elastic components of the infrastructure

6. The Network as a Partner in Cloud Computing Amazon’s “Elastic IP” is an application-driven approach to integrating the Network and the Cloud OpenStack includes Network services as one resource it virtualizes as with CPU/server and Storage –OpenStack’s Quantum interface defines how a virtual network can be created to “host” CPU and other elements Quantum does not define the technology to create virtual networks Cloud provider is responsible for mapping their technology to virtual network models

7. OpenStack Quantum With Folsom release OpenStack users have OpenStack Quantum, an industry-standard, open API for Cloud Networking orchestration –Providing abstraction layer –Instrument to solve Network Operations problems in Cloud Computing and virtualized Data Centers –Decouples operations from network mechanics –OpenStack had API for Compute called “Nova” Networking was hardcoded Quantum makes Networking Subsystem pluggable, modular, standard interface to run any number of virtual networking solutions Quantum allows to create virtual Networks in an industry- independent way, attach those networks to VMs and orchestrate configuration of services

8. Why is it important to break Networking out into its own API? Clouds are still young and evolving quickly –Enable technologies to evolve independently –Different groups are focused on different aspects, if coupled would have to evolve in lockstep and would increase dependencies between systems –Innovate and evolve Networking independently of other areas of Infrastructure (e.g. CPU, Storage) Networks never had industry-standard operational interface –Networking lock-in at command line interface Vendor-proprietary, vendor-specific – Inflexible

9. Network Models for Cloud Computing Need to accommodate multi-tenancy and support cloud control of network services can be accommodated by Software Defined Network (SDN) Technology. There are two models for Cloud Computing –The Overlay Model (Cloud-linked Software) creates a virtual network S/W to partition IP addresses into virtual subnetworks and keeps traffic of subnetworks secure & isolated –Network devices agnostic to overlay virtual networks

10. Network Models for Cloud Computing –The Network Model Network Devices create virtual Networks, they manage SDN traffic directly Vendors propose to add software controls to current devices by adapting current network technology and devices that conform to SDN principles, creating the “evolutionary SDN” Others propose to evolve network devices into simpler form, removing routing intelligence and path/traffic management found in devices –centralize in cloud-hosted software

11. What about SDN and the WAN? Both models and missions collide in the WAN –If Cloud virtual networks have to extend beyond data centers in the cloud and outward to the user, it’s difficult to see how network-hosted SDN implementations of virtualization could be avoided Overlay SDNs rely on S/W elements to create virtual networks; hard to ensure user has required S/W Network appliances need flexible way to update S/W WAN QoS can’t be assured as overlay SDN can’t manage traffic handling –Network-hosted SDN can offer same interfaces & services – no change to S/W or devices End-to-end missions favor SDN model implemented in the network – not over it

12. Importance of SDN in Cloud Networking SDN is increasingly accepted as path to Cloud Networking –Meaning the transformation of networks and services to support the use of cloud computing –Navigating the various missions and technology models of SDNs is critical to properly position cloud services and realize advantages of clouds  Knowing cloud provider’s SDN plans, as well as plans of private cloud S/W stack vendors, is the most critical element in assessing these providers’ long-term value  More in Artur’s talk later this afternoon