Towards a Service Architecture for Internet-Scale Systems

1. Towards a Service Architecture for Internet-Scale Systems David E. Culler Computer Science Division U.C. Berkeley ninja.cs.berkeley.edu

2. Future Internet-Scale Systems • Information Devices (~10 Billion) • Connected Stationary Computers (~100 Million) • Scalable Servers (~Million) Ninja Overview

3. Internet-Scale Systems • Extremely large, complex, distributed, heterogeneous, with continuous and rapid introduction of new technologies • Feasible architectures • Decentralized, scalable algorithms • Dynamically deployed agents where they are needed;“Big infrastructure, small clients” • Incremental processing/communications growth • Careful violation of traditional layering • Implementation approach based on incremental prototyping, deployment, evaluation, experimentation Ninja Overview

4. Your PDA connects to the local infrastructure and asks it to build a custom GUI • Next, your PDA asks the infrastructure for a path out to your personal information space, where agents are processing your e-mail, v-mail, faxes, and pages You have complete, secure, optimized access to local devices and your private resources Imagine • You walk into a room Ninja Overview

5. Vision  Goal • The next internet revolution will come from enabling component services and pervasive access • not vertically integrated Information Technology  Dynamic, programmatic creation / composition of scalable, highly available, & customizable services • Automatic adaptation to end device characteristics and network connectivity • Arbitrarily powerful services on arbitrarily small clients using a proactive infrastructure Ninja Overview

6. Outline of the Presentation • Introduction • Ninja Service Architecture • Wide-Area Paths • Base Service Programming Framework • Project Context at Berkeley Ninja Overview

7. Info. Appliances Network Computers Scalable Servers Legacy Servers Spoon feed web pages to PDAs Laptops, Desktops Starting Point: Transcoding Proxies • Transformation, Aggregation, Caching, and Customization (TACC) • Scalability and availability • Limited customizability and locality and no persistence Ninja Overview

8. ProActive Approach • Create a framework that enables programmatic generation and composition of services out of strongly typed reusable components • Key Elements • Structured architecture with a careful partitioning of state • Bases, Active Routers, and Units • Wide-area paths formed out of strongly-typed components • Operators and Connectors • Execution environments with efficient, but powerful communication primitives • Active Messages + capsules • TACC + persistence + customization Ninja Overview

9. Bases • highly available • persistent state (safe) • databases, agents • “home” base per user • service programming environment Wide-Area Path • Active Proxies • not packet routers • soft-state • well-connected • localization (any to any) • Units • sensors / actuators • PDAs / smartphones / PCs • heterogeneous • Minimal functionality: “Smart Clients” Structured Architecture Ninja Overview

10. Personalization Example: Thin Client Access to Legacy Server AP PDA LegacyServer Base HomeBase AP Base AP AP Unit Unit Sensor Sensor Ninja Overview

11. Agent Aggregator Example: Sensor Aggregation AR PDA LegacyServer Base AR Base AR AR Unit Unit Sensor Sensor Ninja Overview

12. Example: TopGun WingMan/Mediaboard Operation AP PDA LegacyServer PDA Proxy Base Image Converter Un-Zip MediaBoard PC Multicast Connector Aggregator AP Mic Camera Ninja Overview

13. NINJA Service Architecture • Operators/Connectors/Interfaces • Paths • Wide-Area Paths • Interface Interconnection • Path Optimization • Units, Active Proxies, and Bases • Services • Service Discovery • Automatic Path Generation • Example Applications • Universal remote control/smart spaces • Universal In-Box/Personal Information Management Ninja Overview

14. Operators: transformation aggregation agents PI provides secure execution environment Connectors: abstract wires ADUs varying semantics uni/multicast Interfaces: strongly typed language independent control channel path changes authentication feedback Operators/Connectors Ninja Overview

15. Wide-Area Paths • Path is a first-class entity • Explicit or automatic creation • Can change dynamically • change path or operators • Unit of authentication: delegate along the path • Unit of resource allocation Ninja Overview

16. WAN Paths: Economics • Key Idea: securely delegate authority to any path component • access your e-mail remotely • authorized services (subscriptions) • authenticated sensor data • Digicash: • Pay-per-use services • Can be one-time (or subscription) Ninja Overview

17. WAN Paths: Optimization • Insert operators into the path: • forward error-correction, e.g., for error-prone wireless links • compression/decompression, e.g., bandwidth constrained links • Change parameters • retransmission windows • settings for wireless or satellites • Reroute path dynamically Ninja Overview

18. Connecting Interfaces • Goal: trivial to connect • can be automated • Connectors are polymorphic • wires carry a generic ADU of type T • automatic marshall/unmarshall • code must be created at instantiation • Enables automated connection and use Ninja Overview

19. Interoperability • Wrapper operators for legacy servers • HotBot, Zip2, Patent server • Generic wrappers for each MIME type • Connectors use TCP, UDP, multicast • Leverage COM objects as operators • Control Excel remotely • Lots of third party components • ODBC/JDBC databases Ninja Overview

20. Services • Service • Highly available program with fixed interface at a fixed location • Strongly Typed Interfaces • Multiple services of a given type compete • Compete on location, price, robustness, “quality”, brand name • Service Discovery • Find “best” service of given type Ninja Overview

21. Automatic Path Creation • Query goal is path creation • Find logical path of operators • Path must type check • Place operators on nodes • Some operators have affinity • Place them first • Add connectors as needed • Create any authentication keys Ninja Overview

22. Service Discovery and Use Four basic steps: • Find a local Active Proxy • Query Service-discovery service • Automatic path creation, including transformations • Generate UI from interface specification

23. Wide-Area Paths (summary) • Creation (explicit or automatic): • Query Service Discovery Service to find logical path of operators • Place operators onto nodes: • Path is unit of resource allocation and authentication • Connectors are polymorphic: entire path must type check - statically • Optimization: • Add (or transpose) operators • forward error-correction • compression/decompression • Change operators, connectors, locations, or parameters • Interoperability: • Wrapper operators for legacy servers • Leverage COM objects as operators Ninja Overview

24. iSpace Execution Environment operator upload • parallel application framework on Bases • RMI++ hides complexity of scalability and availability • Dynamic customization and composition • apSpace is limited execution environment for AR Service request service threads Persistent Storage Managed RMI++ Physical processor Operators Caches Ninja Overview

25. Base Execution Environment • Ninja RMI • Sun RMI compatible serialization and thread management • ninja remote object + TCP or UDP or Multicast UDP (Active Msg soon) + Authenticated public key • iS-box • customizable service VM • Redirector = iSpace Ninja Overview

26. iS-box • Loader Extends JVM to support services • LoadService (URL, name, args) • ListServices • GetService(name) -> svc obj • KillService • Trusted services loaded at startup • Security MGR interposes on method calls • loaded as a trusted service iS-Loader Trusted-Services Security MGR JVM Ninja Overview

27. Push Services into the Infrastructure • GetService returns service object • Programming Model for Service Methods? New service iS-Loader Trusted-Services Service Methods RMI stubs Security MGR JVM Generated by RMI compiler Ninja Overview

28. Multi-Space iS-box iS-box iS-box iS-box Node Node Node Node System Area Network Scalable iSpace • Multi-Space services across group of iS-boxes • List, Get, or Load Service from any • Get returns redirector stub iS-Loader Multi-Space Loader Multi-Space SVC Security MGR JVM Ninja Overview

29. Redirector Stub • Uses almost same RMI dynamic code generation • Produces RMI stub that manages load balancing and fail-over across iS-boxes in iSpace • Allows full spectrum of smart-client, front-end, flat cluster Load Balance / Fail-over Policy RMI stubs Generated by RMI compiler Distributed Objects - not just remote Ninja Overview

30. Prototype Services • iSpace Admin monitor • automatic forms interface • computational econ support • juke box • ninja fax • pilot pager • Digicash mint • 1200 RMI/s on 400 PII w/ jit Ninja Overview

31. Current Hot Debates • Persistent state • Service Programming Model • powerful classes • constraints • Active Proxy Exec. Context • looks like iS-box • Layering of SDS and iSpace • Path Creation methodology Ninja Overview

32. Massive Cluster Clusters Gigabit Ethernet Servers Desktop PCs Wireless Infrastructure Future Devices Cell Phones PDAs Campus-wide Testbed (Millennium) Ninja Overview

33. Emerging Distributed System Architecture Spanning Processing and Access Personal Information Management and “Smart Spaces” Distributed Videoconferencing Room-scale Collaboration Speech and Location Aware Applications ICEBERG Computer-Telephony Services TranSend Extensible Proxy Services MASH Media Processing Services Active Services Architecture Distributed Computing Services: NINJA Computing and Communications Platform: Millennium/NOW Ninja Overview

34. NINJA and ICEBERG • NINJA: Distributed Service Architecture • Service model based on Operators, Paths, Services • Platform model based on Units, Active Routers, Bases • ICEBERG: Computer-Telephony Integration • IP-based backbone for cellular networks • Mobility and service interoperability in the context of diverse access networks • Performance issues: GPRS scheduling and IP scaling for mobile telephony applications • New services: Smart Spaces and PIM Ninja Overview

35. Experiment: PDA Bazaar • Deploy/use pervasive computing infrastructure in Soda Hall • Provide Ninja iSpaces • Build an initial community (200 PP3 / Workpads) • Watch and evaluate • information broadcast channels • seminars, lecture content • news/sports/stocks • shared information • calendars, room reservations • collaborative note-taking and brainstornming • Smart spaces and device control Ninja Overview

36. Time Travel Evaluate using today’s too expensive technology to prototype tomorrow’s systems existing technology to understand its weaknesses Design new computing systems architectures Deploy understand implementation complexities and sources of performance gain/loss Berkeley Tradition of Experimental Computing Systems Research

37. Internet-Scale Systems Research Group Lead the evolution of the Internet through long-term research combined with the deployment of novel real-world large-scale systems and protocols • Unify on-going and future research projects in distributed computing, network protocols, services, access, new applications • Facilitate technology transfer and standardization • Work closely with industrial partners in an open laboratory environment • AT&T becoming a charter member Ninja Overview

38. Benefits of Sponsorship • Involvement with outstanding Berkeley graduate students • Participation in large-scale, inter-disciplinary, pre-competitive research efforts with only modest investment, leveraging investment of other industrial partners • Access to all ISRG-developed software, prototypes, simulation tools, and testbeds • Early access to group’s research results through on-campus participation and retreats • Support the expansion of cadre of researchers with expertise in Internet-scale systems Ninja Overview

39. Emerging Communications Infrastructure of the Future • The Challenge • Network-based applications becoming increasingly service intensive • Computational resources embedded in the switching fabric • Dealing with heterogeneity, true utility functionality, security, service discovery • Computing • Powerful services on “small clients” because the intelligence is in the infrastructure • Communications • High bandwidth backbones plus diverse access networks • Third generation cellular systems • Home networking • Components