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Globe

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Globe Uniqueness. Too much data, too little resources (bandwidth, etc.) Caching helps ... Explored Globe, Cactus, and other EuroGrid favorites in the context of ... – PowerPoint PPT presentation

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Title: Globe


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Globus
  • Grid Middleware Toolkit
  • Otto Sievert
  • CSE 225
  • 8 June, 2000

3
Globe
  • and other European Grid Activities
  • Otto Sievert
  • CSE 225
  • 8 June, 2000

4
EGRID
  • European Grid Community
  • Collaborative community, not a standards group
  • Commercial and Academic Interests
  • www.egrid.org

5
European Tour
  • Netherlands
  • Germany
  • Poland
  • Italy
  • Sweden

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Grid Theme 1
  • Be very (very) careful when choosing a project
    name.

11
Amsterdam Globe
  • Vrije Universiteit
  • Maarten van Steen
  • Andrew Tanenbaum
  • Middleware to facilitate
  • large-scale distributed applications
  • Web focus
  • object-based coherency

12
Globe Uniqueness
  • Too much data, too little resources (bandwidth,
    etc.)
  • Caching helps
  • Data Coherency integral to Cache Policy
  • Release constraint of a single replication/
    distribution policy for all objects
  • example web pages

13
Globe Object
  • Physically Distributed
  • Replicated
  • Distribution Policy

14
Globe Local Object
  • 4 subobjects (minimum)
  • Modularity

15
Globe Binding
  • 1. Name server
  • 2. Object handle
  • 3. Location service
  • 4. Contact points
  • 5. Choose point
  • 6. Repository
  • 7. Protocol
  • 8. Bind!

16
Legion Binding
  • Two-stage name resolution
  • Binding agent
  • No implementation repository

17
Autopilot Binding
  • 1. Sensor registers with the sole manager
  • 2. AP client requests sensors from the manager
  • 3. Manager returns available sensors
  • 4. Client and sensor communicate directly

18
Globe Claim Remote Object Model Lacks Replication
  • Globe
  • objects can be replicated
  • still maintain one state
  • allows complex coherency policies
  • Legion
  • in theory, supports replication
  • replicated state
  • allows some but not all coherency policies
  • in practice is not allowed

19
Globe Architecture
  • Why all these servers?
  • separate naming from locating
  • allow extensible binding protocols (?)

20
Grid Theme 2 Communication
  • Centralized
  • NWS
  • Globus MDS
  • Simple Management
  • Single Point of Failure
  • Distributed
  • NetSolve
  • Frans Sensor Net
  • Complex Management
  • Scalable
  • Mixed
  • Legion
  • Globe
  • Autopilot

21
Globe Implementation Example
  • Set of HTML/image/ Java files
  • One semantics subobject
  • browsers arent that extensible, so use gateway

gateway
http//globe.foo.edu8989/dir/file.html
browser
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Globe Example (contd)
  • Replication Policies
  • Object-based
  • Permanent store
  • Object-initiated store
  • Client-based
  • Client-initiated store
  • How is this any better than what we have now?

23
Globe Live Demo ...
24
Globe Location Service
  • Scalability Questions
  • Tree Heirarchy
  • again Legion-like in its worst-case behavior
  • Typical soln assumes mobile client
  • Globe soln assumes mobile software

25
Does This Work?
  • Single experiment - 5 wk. web server trace
  • compare
  • no caching
  • various complex replication/coherency policies
  • automatic adaptive policy
  • Results
  • (essentially) any replication scheme wins big
  • individual object adaptivity didnt perform well

26
Globe Conclusion
  • Explicit coherency is clearly a Good Thing
  • Security?
  • Representative implementation?

27
Germany Cactus
  • Albert Einstein Institute, Potsdam
  • Thomas Radke
  • Ed Seidel
  • Distributed Astrophysics
  • Software Engineering
  • NCSA hot code

28
Cactus
  • Separate CS from disciplinary science
  • Flesh CS architecture
  • Thorns science modules
  • 2-stage compilation
  • encapsulation
  • modularity
  • reuse

29
Cactus Compilation
  • Two stage
  • Permanently bind thorns Perl
  • Compile binary C/F77
  • Efficient
  • Dont carry unneeded thorn info

30
Grid Theme 3 Applications
  • Numerical, or Non
  • Computation vs. Specialization
  • Performance Measures
  • Execution Time
  • Scale
  • Efficiency
  • Distribution

31
Grid Theme 4 Transparency
  • Ease of Use vs. High Performance
  • As system becomes opaque, EoU increases
  • As system becomes opaque, Perf decreases
  • Where is the balance?

32
Germany Gridware
  • 1999 San Jose-based merger of two companies
    Genias GmbH and Chord (U.S.)
  • CoDINE
  • Compute farm load balancing system
  • Recently adopted by Sun
  • PaTENT
  • WinNT MPI

33
Grid Theme 5 Commoditization
  • Reuse is strong in the Grid
  • Resources (Beowulf)
  • Middleware (Globus, PaTENT)
  • Applications (Cactus)
  • Industry is influential
  • Largest grid apps in use today are commercial
  • Grid-ernet is profitable

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To This Point ...
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Germany Unicore
  • UNIform Computer Resources (German SC access)
  • Goal is to provide uniform access to high
    performance computers - painful to learn
  • OS details
  • Data storage conventions
  • Administration policies
  • 3 phase project
  • I self-contained jobs
  • II remote data access
  • III concurrent remote execution

36
Unicore (contd)
  • How is this done?
  • Web (Java) user interface
  • X.509 authentication
  • Network Job Supervisor
  • interprets Abstract Job Objects
  • manages jobs and data
  • interfaces with local batch systems (like
    LoadLeveler and CoDINE)
  • vs. Globus?

37
Poland POL-34
  • National Grid
  • Very like the system used by Unicore, a
    collection of widely-distributed parallel
    computers
  • Tree-connected ATM network

38
POL-34
  • Yellow 2 Mb/s
  • Red 34 Mb/s
  • Cyan 155 Mb/s
  • Single administrative domain via Virtual Users
    (skirting the grid issue)
  • Use Load Sharing Facility (LSF)

39
Italy SARA
  • University of Lecce, Italy Giovanni Aloisio (with
    Roy Williams of Caltech)
  • Synthetic Aperature Radar Atlas
  • Distributed data-intensive app
  • Alan Su and the UCSD AppLeS group is involved

40
SARA Architecture
  • The goal easy, fast, efficient retrieval and
    processing of SAR image data
  • Issues
  • data is distributed, stored in tracks
  • complex hierarchical system
  • Prototypical grid app

41
Sweden Computational Steering
  • Parallelldatorcentrum Royal Institute of
    Technology Per Oster
  • Using Globus and the Visualization Toolkit (VTK)
    to steer a single CFD code.
  • Little data available
  • Eclipsed by Autopilot

42
Grid Theme 6 Heterogeneity
  • Some attempt to hide it
  • Globus, CORBA, Java/Jini
  • Some take advantage of it
  • Netsolve, Ninf
  • Some characterize and manage it
  • AppLeS (SARA), NWS

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To This Point ...
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Conclusion
  • Explored Globe, Cactus, and other EuroGrid
    favorites in the context of
  • Communication architectures
  • Grid application characteristics
  • Grid transparency
  • Commodity computing influence
  • Grid heterogeneity

45
Network Weather Service (NWS)
  • Rich Wolski, U. Tenn.
  • Monitors and Predicts Grid Resources
  • network latency, bandwidth
  • CPU load, avail. Mem.
  • Central NWS data server
  • nws.npaci.edu/NWS
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