System Architecture for Extreme Devices

1. Massive Cluster Clusters Gigabit Ethernet System Architecture for Extreme Devices David Culler http://www.cs.berkeley.edu/~culler U.C. Berkeley DARPA Meeting 9/21/1999

2. Recap: Convergence at the Extremes • Arbitrarily Powerful Services on “Small” Devices • massive computing and storage in the infrastructure • active adaptation of form and content “along the way” • Extremes more alike than either is to the middle • More specialized in function • Communication centric design • wide range of networking options • Federated System of Many Many Systems • Hands-off operation, mgmt, development • Scalability, High Reliability, Availability • Power and space limited => simplicity • Each extends the other Endeavour Sys. Arch

3. State-of-the-Art: Very Large Systems • Scalable Clusters Established • high-speed user-level networking + single system image • naming, authentication, resources, remote exec., storage, policy • Meta-system glue over full OS and Institutional structure • Glunix (UCB), Globus(ANL), Legion (UVA), IPG (NASA), Harness, NetSolve, Snipe (UTK), ... • uniform, multiprotocol communication & access mechanism • personal virtual machine spanning potentially diverse resources • constructed and managed “by hand” • Key challenges • Automatic Composition, Management, and Availability • Scalability to global scale • Ease of development for global-scale services Endeavour Sys. Arch

4. State-of-the-Art: in the small... • Unix-like support in a small form factor + real time seasoning • microkernels dominate • academic: Exokernel, OSKit, ucLinux, ELKS, • Commercial: PSION, GeoWorks, WinCE, Inferno, QNX, VxWorks, javaos, chorusOS, • + PalmOS, BeOS, • Components and mobile objects: jini, corba, dcom, ... => tracks the 80386 • when it becomes ~ 1990 PC Unix will run on it • ability to remove components (modularity) + fault boundaries more important than performance • legacy applications less dominant Endeavour Sys. Arch

5. Design Issues for “Small Device OS” • Current: Managing address spaces,Thread scheduling, IP stack, Windowing System, Device drivers, File system, Applications Programming Interface, Power management • Challenge: How can operating systems for tiny devices be made radically simpler, manageable, and automatically composable? Endeavour Sys. Arch

6. 2 Axis Mag. Sensor N W E 2 Axis Accelerometer S Light Intensity Sensor Humidity Sensor Pressure Sensor Temperature Sensor Emerging Devices • RF COTS Mote • Atmel Microprocessor • RF Monolithics transceiver • 916MHz, ~20m, 4800 bps • 1 week fully active, 2 yr @1% • Laser mote • 650nm laser pointer • 2 day life full duty CCR mote • 4 corner cubes • 40% hemisphere Endeavour Sys. Arch

7. Micro Mote - First Attempt Endeavour Sys. Arch

8. Service Path Structured Communication-Centric System Architecture • Scalable Info Utility Providers • highly available • persistent state (safe) • databases, agents • service programming environment • Active Proxies • connected to the infrastructure • soft-state, bootstrap protocol • transcoding, • Ubiquitous Devices • billions • sensors / actuators • PDAs / smartphones / PCs • heterogeneous • Service Paths • aggregate flows (rivers) • transcoding operators Endeavour Sys. Arch

9. New Kinds of Nodes become Key • Infrastructure Nodes • powerful network + lots of proc. and storage • interact through the network • Transducer Nodes • network + sensors or actuators • limited processing and state • Interaction Nodes • network + user interface • widely varying capability and size • Communication is the common element Endeavour Sys. Arch

10. Open Clients Clients Clients Clients Servers Clients Clients Servers Servers The Internet The Large: Service-Centric Platform Arch Infrastructure Services • Information Utility is not just storage. It must enable • Distributed Innovation of Scalable, Avail. Services • service registry, aggregate execution env., transparency • persistent dist. data structures • massive fluid storage (ocean) • adaptive high-bandwidth flows (rivers) • Build the infrastructure itself through composition of services Endeavour Sys. Arch

11. Automated Composition and Mgmt • Individual services are strongly-typed active components that can be located through intentional “service discovery” • Application formed as path (or graph) of services • not ad hoc connectivity, nor general planning • reachability and adaptation • Resources allocated and managed in decentralized manner under economic model • translation of value -> resource • platform components enforce allocation • rich body of mechanisms (contracts, auctions, pricing) • natural elevation from resources to higher level services => Simple composition building from complex nodes Endeavour Sys. Arch

12. The Small: radically simple OS for management and composition • Communication is fundamental • treated as part of the hardware. No comm. is like no power • hands off: a direct “user interface” is the exception not the norm • typical device has a network on one side + sensor/actuators on the other • buttons and display a special case • all deployment, development, configuration, mgmt, programming, is through the communication interface • schedule data movement, not arbitrary threads of computation Endeavour Sys. Arch

13. OS as little more than FSM • Primary focus is scheduling discrete chunks of data movement • not general thread scheduling and unlimited memory management • there may be a bounded amount of work to xform or check data • Commands are an event stream merged with sensor/actuator events • General thread must be compiled to sequence of bounded atomic transactions • spaghetti part of an application is configuring the flows • steady-state is straight-forward event processing + signaling unusual events • constant self-checking and telemetry • rely on the infrastructure for hard stuff • correct-by-construction techniques for cooperating FSMs Endeavour Sys. Arch

14. Precursors to the next generation • Operating systems that are not called “operating systems” • eg: modern disk controller • event scheduler handling stream of commands from network link, controlling complex array of sensors and actuators, performing sophisticated calculations to determine what and when (scheduling and caching) as well as transforming data on the fly • automatic connection, enumeration, configuration • but several simplifying assumptions must be removed Complex array of Sensors and actuators Network link: - EIDE, SCSI - FCAL, SSA - USB, 1394 - ??? Endeavour Sys. Arch

15. Massive Cluster Clusters Servers Wireless Desktop PCs Gigabit Ethernet PDAs Future Devices UCB Testbed • 1x300 proc + 10x20 proc SAN clusters across depts. • integrated through multiple gigabit ethernet • extended out throug 100s desktops, RF laptop, IRDA PDA, Cell Phones, Pagers, and numerous motes Cell Phones Endeavour Sys. Arch

16. Plan • Prototype Phase: • Large: 2nd generation NOW arch. + meta-OS efforts + Ninja Service Platform • Small: PalmOS + wince + uc-Linux • simulation environment • Develop: • Automated service composition architecture • FSM-OS and negotiation/mgmt architecture • Deploy widespread services, devices and feeds • Evaluate against high-speed decision making applications Endeavour Sys. Arch