Minutes of GGF9 GridCPR-WG Meeting

[Derek Simmel <dsimmel@psc.edu>]

Folks, below are the collected minutes from our meeting in Chicago. 
Many thanks to our notetakers and other contributors - Comments, 
additions and corrections welcome.

Please do not forget to send your (Grid)CPR Use Cases (short 
descriptions are OK) to Paul Stodghill and the list ASAP - Thanks! - 
Derek


GGF9 - Chicago, Illinois
Grid Checkpoint Recovery Working Group (GridCPR-WG)
Shoeraton Hotel, Michigan Room B
Tuesday October 7, 2003, 2:00~5:30pm

Session Chaired by Derek Simmel
Session Notetakers: Thilo Keilmann & Shantenu Jha

Session formalities:
Opened the meeting
Displayed and reviewed GGF Intellectual Property Policy with attendees
Circulated the attendee list

Reviewed the proposed Agenda:
2:00 Meeting Bootstrap, Introduction and Agenda Review
2:10 Review of GridCPR-WG after 1 year
3:00 Discussion/Revision of GridCPR Objectives,
Architecture, Diagram, Scope, Charter…
3:30 Break (30 minutes)
4:00 Structured Brainstorm to Generate Detailed Outline
of the GridCPR API & Services Architecture GWD-I document
5:00 Document Action Items and Writing Assignments
5:10 Planning for GGF10 (Frankfurt) and GGF11 (Hawaii),
Interim Objectives, and Charter Milestones Updates
5:30 Adjourn

Reviewed GridCPR-WG Administrative Status:
Website updates at http://gridcpr.psc.edu/GGF/
Mailing and Archive addresses

Reviewed GGF GridForge:
GridCPR Chairs (Derek Simmel and Thilo Kielmann) are administrators for 
the GridCPR project.
All attendees are encouraged to create an account via 
http://forge.gridforum.org/
Folks should send e-mail to Derek Simmel <dsimmel@psc.edu> to get your 
GridForge account added to the GridCPR project.

Reviewed 1st year of GridCPR-WG activities:
GGF5 (Edinburgh)
- Held a BoF session to gauge community interest in GridCPR
GGF6 (Chicago)
- Presentations
  "Grid Checkpointing in the European DataGrid project" - Massimo 
Sgaravatto
  "The PSC CPR System: Scope, Applicability, and Implementation (SAI)" 
- Nathan Stone
  "Application-level Checkpointing for Parallel Applications" - Paul 
Stodghill
  "Checkpoint Recovery in Cactus 4.0" - Gabrielle Allen
  "Checkpoint Recovery in Condor" - Derek Simmel
- Initial Scoping Discussion
GGF7 (Tokyo)
- Working Group Charter approved by GFSG (November 2002)
- Initial Draft of GridCPR Architecture Document reviewed
- More requirements, interactions and scope discussion
GGF8 (Seattle)
- GridCPR Architecture Discussion
  Coordinated vs. Uncoordinated Checkpoints
  Named Checkpoints
  Checkpoint Data Management
  Job Run complexity (not just a single binary, multiple systems,…)
  Resource broker perspectives
  Security for checkpoint files
- Use Case discussions
  Examined various different views of GridCPR as represented among 
attendees
    Mikel and Shantenu from RealityGrid
    Paul Stodghill from Cornell
    Tom Goodale and Thilo Kielmann from GridLab
    Karpjoo Jeony, Konkuk University
    Heon Yeom, Seoul National Univ

"Do we still want to write these (and others we will gather) up in more 
detail and publish them as an informational document?" (e.g. Paul 
Stodghill's use-case summary sent to the list)

(Rough consensus among attendees is to pursue development of a 
use-cases document)

Reviewed GridCPR "Rough Sketch" and Architecture Goals/Audience from 
GGF8

GridCPR Goal:
Applications developed correctly using the GridCPR API, which write 
periodic checkpoint data sets, and which are interrupted during 
execution, will be able to continue operations on a remote system 
within a Grid, starting at an interim state represented by a retrieved 
checkpoint data set recorded during the original execution.

GridCPR API Specification Audience:
- Grid Application Developers

GridCPR Service Specification Audience:
- Grid Platform Developers and Vendors
- Grid Resource Operators

Other Stakeholders:
- Grid Standards and Specifications Developers

"What is the GRID in GridCPR?"
- User-level checkpointing
- Heterogeneity of source and restart platforms
- Ability to migrate a job from n nodes of a system to m nodes (likely 
on a different system)
- Checkpoint API should be available everywhere
- Data/Checkpoint files are reusable anywhere
- Simple recompile for new platforms - no need to recode for a new 
platform's checkpoint service

(Additional requirements)
- the grid must not be visible in the API (opaque)
- no dependencies to local names (e.g., volume names)

Action: vikas.deolaliker@sun.com to submit use case

Discussion ensued regarding existing APIs / uses of CPR

Derek Simmel reviewed the European Data Grid CPR API from Massimo 
Sgaravatto's presentation.

Nathan Stone reported on portable CPR API early experience at the 
Pittsburgh Supercomputing Center
- user-level API implemented originally on Lemieux (Terascale Computing 
System)
- file-oriented semantics
- can also accommodate memory semantics
- checkpoint database (metadata) must be secured against tampering

Paul Stodgehill (Cornell)
- making checkpointing transparent with compiler (and middleware)
- file-oriented APIs compatible
- expect GridCPR API and Service to work as a drop-in replacement


(Break 3:20-3:45pm)


(Grid)CPR Use Cases Document (to become GWD-I document)
Action: Paul Stodghill taking lead on pulling this informational 
document together
  Will generate rough template with points of comparison
  Problem Statement
  - What’s difficult for this particular scenario w.r.t. GridCPR
  “How we would use GridCPR” for {this use case}
  Within scope defined by Charter statement
  Will send call for scenarios to mailing list
  No formatting and other requirements
  - Make it easy for people to send in content
  Due dates
  - Scenarios in to Paul by October 31, 2003
  - Paul send out first draft November 30, 2003
  - Revise via mailing list discourse for complete draft by January 15, 
2004
  - Send draft to be presented at GGF10 for final editing to GGF 
February 1, 2004
  - Complete final document review on/shortly after GGF10 -> GGF Doc 
editor

Example use cases could include:
- migrate from n to m nodes
- migrate from platform a to platform b

GridCPR Architecture Document (revamp original GWD-I document)
Action: Nathan Stone, Derek Simmel & Raghu Reddy (PSC ) will draft the 
outline for the Architecture Document
  Headlines for major sections
  Unresolved issues
  Scope questions
  Due Dates
  - Draft out to mailing list by October 31, 2003.
  - Review period - via mailing list - November 30.
    - Including meat added by gridcpr-wg members as we go
  - Adding meat to bones…
  - Jan. 15th - Checkpoint of the Architecture Document Outline
  - Out for discussion (send in to GGF) Feb 1.

GridCPR World View Illustration
Action: Thilo will send a diagram of “Thilo’s view of GridCPR” (with 
cunningly inserted errors as an exercise to readers ;)
  Send to mailing list by October 20, 2003.
  Supplement & organizing view for architecture document
  It will be a piece of meat for the Architecture Doc
  Comments back to mailing list between Oct 20~Nov 30, 2003.

Documentation of Existing APIs
Action: Those with some documentation of existing related APIs should 
send pointers to them to the mailing list, e.g.,
  - Nathan Stone, PSC CPR API
  - European Data Grid
  - Cactus
  - Paul Stodghill, Cornell
  - Others?
Send your descriptions to the mailing list
We will post them to the GridCPR website (later GridForge archive)

Action: Derek Simmel will review requirements for publishing a GGF 
Recommended API regarding number and form of required independent 
implementations.

Action: Stephen Pickles to ensure [Reality Grid] Use case is contributed

Discussion of Charter:
Original milestones were too ambitious given limited availability of 
resources

Proposed Charter revisions to milestones:
Spring 2004 - GGF10 Frankfurt
	Review Use Cases Document
	Review Architecture Document
	Initiate Draft API document
Summer 2004 - GGF11 Hawaii
	Review Final Use Case & Architecture documents
	Submit finalized GWD-I documents to GGF Editor
	Review Draft API
Fall 2004 - GGF12
	Review Existing Implementation Efforts
	Review Final API document & submit to GGF Editor
	Determine the nature and scope of required underlying GridCPR services
Spring 2005 - GGF13
	Review Draft GridCPR Services Doc (if needed)
Summer 2005 - GGF14
	Review Final GridCPR Services Doc & submit to GGF Editor

Action: Derek Simmel will submit charter milestone revisions to GFSG 
for review.

Meeting Adjourned at 5:30pm

---
Derek Simmel <dsimmel@psc.edu>
Grid Computing Specialist
Pittsburgh Supercomputing Center
4400 Fifth Avenue
Pittsburgh PA 15213
(412) 268-1035