Dustin Mihalik's Blog

PDC: WinFS Syncronization

• WinFS Syncronization
• WinFS Item Store
  • Similar to what we've before
  • Focusing on WinFS Syncronization and Objects
• Syncronization Schnarios
  • At home:
    • Keep my data in sync across my home machines
    • Share pictures with friends and family
    • Take my music with me
      • Sync music with devices
      • Push music to car
  • At work
    • Share documents with coworkers
      • When documents change, want to see them quickly
    • Keep my contacts in sync with enterprise servers and onine services
      • Sharepoint, etc
    • Sync with PDA's, Cameras, etc
• User Benefits
  • Duh.
• Developer Benefits
  • Turns a single-user app into a collab app
  • Best way to pull data from external sources into winfs
  • Better user experience
    • Standard methods for solving issues
• Sync overview
  • Approach
    • Multi-master replications
      • Replicas make changes independently
    • Net change syncronization
      • Looking at cumulative changes, not logs
    • Set of common services for all data sources and schemas
      • Change tracking, change enumeration, conflict handling
  • Extending
    • Schema design
      • Granularity of change unites is declared in the WinFS Schemas
    • Custom conflict resolution handlers
      • Extend the system conflic policies with code
    • Sync adapters
      • Outside data sources for one way or bidirectional...
• Demo Using Synchronizatioin
  • Location in chicago with site report
    • Has text, contacts,
  • Site report is replicated, then photos are added
  • Report is then replicated back.
  • Demos Sync & InfoAgent
    • InfoAgent uses Itemwatcher API
  • Very clean demo of a report being syncronized and popup showing up.
• How do we make this work?
  • Change tracking
    • WinFS records change tracking information in every item
      • Maintains versions and tombstoesn through all operations
        • Can remember what state of each item is
        • tombstone when stuff is deleted
      • Common service for Sync, InfoAgent, and all WinFS applications
      • Occurs at the level of *change units*
  • Change units are defined by schema designer:
    • Reduce conflits
    • Reducce transport load
      • Only stuff that has changed will sync
    • Chop up stuff into parts that can be changed together.
• Demo of Creating a replica
  • This stuff is built on more current version
  • He used the term "Uniquified"
  • Handles creating replicas and conflict handling
• Architecture
  • Web portals into WinFS
  • Hotmail into WinFS
  • AD & Exchange into WinFS
    • MS already wrote exchange
  • Smartphone & PDA's
• Syncronization Adaptor
  • Outbound from WinFS
    • Figure out what changed
    • Transform to external data
    • Apply to remote
    • Resolve conflicts on remote
  • Inbound to WinFS
    • Enumerate changes from external store
    • WinFS sync will resolve conflicts
• Change enumeration
  • Starts with the replica and the caller's state
  • Finds new, changed, deleted items
• Sync Adaptors are not really easy to write
• Key Takeaways
  • Sync support built into WInFS & Longhorn
  • Enabling for you application is easy
  • Also very powerful
• PDC build does not contain SyncAPI
• PDC build does not schematize Sync config data