Get documents about "Berkeley NOW
Shared by: HC12100408954
-
Stats
- views:
- 1
- posted:
- 10/4/2012
- language:
- English
- pages:
- 39
Document Sample
Towards a Service Architecture for
Internet-Scale Systems
David E. Culler
Computer Science Division
U.C. Berkeley
ninja.cs.berkeley.edu
Future Internet-Scale Systems
• Information
Devices
(~10
Billion)
• Connected
Stationary
Computers
(~100 Million)
• Scalable
Servers
10/4/2012 Ninja Overview
(~Million) 2
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
10/4/2012 Ninja Overview 3
Imagine
• You walk into a room
• 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
10/4/2012 Ninja Overview 4
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
10/4/2012 Ninja Overview 5
Outline of the Presentation
• Introduction
• Ninja Service Architecture
• Wide-Area Paths
• Base Service Programming Framework
• Project Context at Berkeley
10/4/2012 Ninja Overview 6
Starting Point: Transcoding Proxies
Info. Appliances
Scalable Servers Network Computers
Legacy Servers
Spoon feed web
pages to PDAs
Laptops, Desktops
Transformation, Aggregation, Caching, and Customization (TACC)
Scalability and availability
Limited customizability and locality and no persistence
10/4/2012 Ninja Overview 7
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
10/4/2012 Ninja Overview 8
Structured Architecture
• Bases
– highly available
Wide-Area Path
– persistent state (safe)
– databases, agents
– “home” base per user
– service programming environment
• Active Proxies
– not packet routers
– soft-state
– well-connected
– localization (any to any)
• Units
– sensors / actuators
– PDAs / smartphones / PCs
– heterogeneous
– Minimal functionality: “Smart Clients”
10/4/2012 Ninja Overview 9
Example: Thin Client Access to
Legacy Server
PDA AP
Legacy
Server
Personalization
Home
AP Base Base
Base
AP
Unit AP
Unit
Sensor Sensor
10/4/2012 Ninja Overview 10
Example: Sensor Aggregation
PDA AR
Legacy
Server
AR Base
Base
Agent
Aggregator
AR
Unit AR
Unit
Sensor Sensor
10/4/2012 Ninja Overview 11
Example: TopGun
WingMan/Mediaboard Operation
PDA AP
Legacy
Server PDA Proxy
Image Converter
Base MediaBoard
Un-Zip
Multicast PC
Aggregator
Connector
AP
Mic Camera
10/4/2012 Ninja Overview 12
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
10/4/2012 Ninja Overview 13
Operators/Connectors
Operators:
– transformation
– aggregation
– agents
– PI provides secure
execution environment
Connectors:
– abstract wires Interfaces:
– ADUs – strongly typed
– varying semantics – language independent
– uni/multicast – control channel
» path changes
» authentication
» feedback
10/4/2012 Ninja Overview 14
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
10/4/2012 Ninja Overview 15
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)
10/4/2012 Ninja Overview 16
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
10/4/2012 Ninja Overview 17
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
10/4/2012 Ninja Overview 18
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
10/4/2012 Ninja Overview 19
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
10/4/2012 Ninja Overview 20
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
10/4/2012 Ninja Overview 21
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
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
10/4/2012 Ninja Overview 23
iSpace Execution Environment
operator
upload
Service request
service threads
Managed RMI++ Persistent
Storage
Physical
processor
Caches Operators
• parallel application framework on Bases
– RMI++ hides complexity of scalability and availability
– Dynamic customization and composition
• apSpace is limited execution environment for AR
10/4/2012 Ninja Overview 24
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
10/4/2012 Ninja Overview 25
iS-box
• Loader Extends JVM to
support services
– LoadService (URL, name, args)
– ListServices
–
Trusted-Services
GetService(name) -> svc obj
–
iS-Loader
KillService
• Trusted services loaded at
startup
• Security MGR interposes Security MGR
on method calls JVM
– loaded as a trusted service
10/4/2012 Ninja Overview 26
Push Services into the Infrastructure
Trusted-Services
iS-Loader
New
service
Service
Methods
RMI
Security MGR
stubs
JVM
Generated by RMI
compiler
• GetService returns service object
• Programming Model for Service Methods?
10/4/2012 Ninja Overview 27
Scalable iSpace
Multi-Space
iS-box iS-box iS-box iS-box
Node Node Node Node
System Area Network
• Multi-Space services
Multi-Space Loader
across group of iS-
Multi-Space SVC
boxes
iS-Loader
• List, Get, or Load
Service from any
• Get returns redirector Security MGR
stub JVM
10/4/2012 Ninja Overview 28
Redirector Stub
• Uses almost same
RMI dynamic code
generation Load Balance /
Fail-over Policy
• Produces RMI stub
that manages load
balancing and fail- RMI
over across iS-boxes stubs
in iSpace
• Allows full spectrum
of smart-client, front-
Generated by RMI
end, flat cluster compiler
Distributed Objects - not just remote
10/4/2012 Ninja Overview 29
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
10/4/2012 Ninja Overview 30
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
10/4/2012 Ninja Overview 31
Campus-wide Testbed (Millennium)
Massive Cluster
Gigabit Ethernet Clusters
Servers
Desktop
PCs
Wireless
Infrastructure
Future Devices
PDAs Cell Phones
10/4/2012 Ninja Overview 32
Emerging Distributed System
Architecture Spanning Processing and
Access
Personal Information Management and “Smart Spaces”
Speech and Location
Aware Applications
Distributed Videoconferencing
Room-scale Collaboration ICEBERG
Computer-Telephony Services
MASH Media Processing Services
TranSend Extensible
Proxy Services
Active Services Architecture
Distributed Computing Services: NINJA
Computing and Communications Platform: Millennium/NOW
10/4/2012 Ninja Overview 33
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
10/4/2012 Ninja Overview 34
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
10/4/2012 Ninja Overview 35
Berkeley Tradition of Experimental
Computing Systems Research
Evaluate Time Travel
using today’s too
existing technology expensive technology
to understand to prototype
its weaknesses tomorrow’s systems
Design
new computing
systems
architectures
Deploy
understand implementation
complexities and sources of
performance gain/loss
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
10/4/2012 Ninja Overview 37
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
10/4/2012 Ninja Overview 38
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
