Towards I-Space Ninja Mini-Retreat June 11, 1997 David Culler, Steve Gribble, Mark Stemm, Matt Welsh Computer Science Division U.C. Berkeley

6/11/98Ninja I-space2 Outline Placing I-Space within Ninja System Architecture TACC as a starting point Ninja I-Space Requirements Java opportunities Strawman Framework Discussion

6/11/98Ninja I-space3 Ninja Perspective Information Devices (~10 Billion) Connected Stationary Computers (~100 Million) Scalable Servers (~Million) Units Active routers Bases Small Devices become Powerful through the infrastructure

6/11/98Ninja I-space4 Example: Super Mail Server Diverse ubiquitous access connected or disconnected move function and customization into scalable service ex: filter with arbitrary predicate Kiosk Desktop Laptop Customized Mail Service PDA

6/11/98Ninja I-space5 Operational Behavior Devices find ARs Build a “wide area path” of connectors and operators to service. Active transformation at each step Careful management of state Units Active routers Bases

6/11/98Ninja I-space6 Generalized Active Messages Message arrival causes handler to fire and perform computation to additional communication –named or encapsulated Units initiate proxy in AR, ARs route and transcode, Base services react Each layer has a distinct execution environment –control model, storage, protection, events, fault behavior

6/11/98Ninja I-space7 I-Space Execution environment for scalable, available, customizable, and easily constructed Base services Units Active routers Bases You are here

6/11/98Ninja I-space8 Toward the I-Space Design TACC –framework for building a restricted class of scalable, available services –transformation, aggregation, caching –logically stateless Java –safe language suitable for mobile code –a world of distributed objects –oriented to virtual machines

6/11/98Ninja I-space9 TACC review Service specified by FE thread logic Worker = function operator (state-free transformation) –Shared among services, unix process protection Very limited hard state Manager responsible for logical and physical mapping –monitors progress and resources –simple restart model Service request Front-end service threads Worker Processes Caches User Profile Database Manager Physical processor

6/11/98Ninja I-space10 Ninja I-space requirements Persistent state Polymorphic operators –functionally equivalent operations on strongly typed content User customizable services –customize operators within service –customize service logic Composable services

6/11/98Ninja I-space11 Key lesson from TACC Clean division of responsibilities –datapath (transformational workers) –control(service thread logic) –management –manipulation of persistent state Obtain performance and ease of service construction by constraining the programming methodology –not by introducing many low level primitives –critical to find the “sweet spot”

6/11/98Ninja I-space12 Java - the natural step Service thread ~ servlet Worker operation ~ method invocation Overloading Managed worker invocation => extension to RMI –mapping from type to method –mapping to physical resources –monitoring progress, failure, restart

6/11/98Ninja I-space13 Opportunities User customization of operators is easy –provide “load worker” request –extend manager mapping to include user context Path to user composition of services –expose “worker” API –active service methods Active Service Worker Processes Caches Manager

6/11/98Ninja I-space14 Opportunities (cont) Worker VM allows sandbox to be better tailored VM offers additional point of fault handling control

6/11/98Ninja I-space15 Millennium Testbed (started 9/97) Gigabit Ethernet SIMS C.S. E.E. M.E. BMRC N.E. IEOR C. E. MSME NERSC Transport Business Chemistry Astro Physics Biology Economy Math

6/11/98Ninja I-space16 Partnership => Testbed for I.S. Research Gigabit Ethernet PDAs Cell Phones Future Devices Wireless Infrastructure