MediaWiki Developer Meet-Up 2009/Notes/XMPP

• Day/Time: Saturday April 5th 10:30-11:30
• Topic: XMPP recentchanges feed (notes from dev meeting: [1])
• Session leader: Daniel Kinzler (Duesentrieb)
• Participants: Brion, Catrope, Leafnode, Luca de Alfaro, Rainman, Dani

• Two use cases:
  • RC feed (low number of users, high traffic)
  • Watchlist feed (high number of users, low traffic)
    • Needs auth, does that work with XMPP?
    • Alternatively, use unguessable channel name that user can change (in prefs)
      • Could also be used for watchlist RSS
• Performance requirements
  • No idea how many users is sustainable, find out by experimentation?
    • Subscribers through Jabber.org, Gmail.com, etc. are relayed; are the messages collapsed too? (i.e. one msg for multiple rcpts)
• Pop-ups or IM profile?
  • With pop-ups, you can filter by event type
    • Could be used to facilitate differentiation (diffs, metadata, both, ...)
• API XML as payload, options for other formats (JSON) too?
  • XML payload wouldn't produce < crap, making parsing easier
• Info in payload
  • RC metadata
  • Full text of new rev (optional)
  • Machine-readable (unified) diffs with GNU diff (needs diff cache modification)
    • Would reduce bandwidth used for incremental rev fetching
    • Link diffs (off-topic)
• XMPP can also be used in a pull fashion to query the API
• Get UDP packets from main cluster to TS
  • UDP packets are limited to ~64K
    • Fulltext/diff inline when small enough, flag+XMPP query when bigger?
  • Leafnode will write a tool for relaying UDP packets
  • Catrope will write a tool for producing UDP packets from RC with API XML payload
    • Duesentrieb has a pluggable UDP framework lying around somewhere
  • For testing, generate UDP packets from TS à la River's RC ticker