Towards ISpace Ninja MiniRetreat June 11, 1997

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Towards I-SpaceNinja Mini-RetreatJune 11, 1997

• David Culler, Steve Gribble, Mark Stemm, Matt
  Welsh
• Computer Science Division
• U.C. Berkeley

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Outline

• Placing I-Space within Ninja System Architecture
• TACC as a starting point
• Ninja I-Space Requirements
• Java opportunities
• Strawman Framework
• Discussion

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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
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Example Super Mail Server
Kiosk

• Diverse ubiquitous access
• connected or disconnected
• move function and customization into scalable
  service
• ex filter with arbitrary predicate

PDA
Laptop
Desktop
Customized Mail Service
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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
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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

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I-Space

• Execution environment for scalable, available,
  customizable, and easily constructed Base services

You are here
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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

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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

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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

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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

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Java - the natural step

• Service thread servlet
• Worker operation method invocation
• Overloading
• Managed worker invocation gt extension to RMI
• mapping from type to method
• mapping to physical resources
• monitoring progress, failure, restart

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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
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Opportunities (cont)

• Worker VM allows sandbox to be better tailored
• VM offers additional point of fault handling
  control

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Millennium Testbed (started 9/97)
Business
SIMS
BMRC
Chemistry
C.S.
E.E.
Biology
Gigabit Ethernet
Astro
NERSC
M.E.
Physics
N.E.
Math
IEOR
Transport
Economy
C. E.
MSME
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Partnership gt Testbed for I.S. Research
Wireless Infrastructure
Future Devices
PDAs
Cell Phones