performance challenges for the open web stanford cs193h 29 september 2008
TRANSCRIPT
Performance Challenges
for the Open Web
Stanford CS193H29 September 2008
Background: making the web work better
I’ve been abusing web browsers for 15 years
- http://josephsmarr.com
I used to work on AJAX / JS performance- http://josephsmarr.com/2007/07/25/high-performance-javascript-oscon-2007- Video:
http://developer.yahoo.net/blogs/theater/archives/2007/08/joseph_smarr_highperformance_j.html
Now I’m helping open up the social web- http://josephsmarr.com/2008/09/22/tying-it-all-together-implementing-the-open-web-web-20-expo-
new-york- Weekly video podcast: thesocialweb.tv
Open Web has new performance challenges- Making multiple sites play well together- Privacy, transparency, flexibility, simplicity
In a world with lots of socially-aware sites…
…how do the pieces fit together?
…and what will the new
Social Web look like?
Reminder: The social web today is broken…
On each site, we still have to:-Re-create an account-Re-enter our profile info-Re-find our friends-Re-establish our relationships
New social apps have limited options:-Create yet-another-silo (and start from scratch)
-or--Make a widget inside an existing walled garden
…but we know how to make things better!
Create a portable, durable online identity
OpenID- Sign up / sign in with an existing
account- Link / share your profile data between
sites
Example: Sign up for Plaxo with OpenID
Create a portable, durable online identity
OpenID- Sign up / sign in with an existing account- Link / share your profile data between sites
rel=me (XFN)- Consolidate your online identity with me-links
Social Graph API- See what your users said about themselves
Build and maintain real relationships
Contact APIs- Find people from your current address book- Leverage previously established relationships
OAuth- Share private data between trusted sites
Friends-list portability- Continuous discovery across multiple sites
“A periodic check of new people from your networks on other sites”
Stay up-to-date with the people you know
OpenSocial- Build social apps that can run anywhere
OpenSocial
OpenSocial: Large and Growing Rapidly
Stay up-to-date with the people you know
OpenSocial- Build social apps that can run anywhere
RSS / Atom- Syndicate your activity to share with others
Jabber (XMPP)- Real-time update stream between sites
Building blocks in action: contacts portability
User signs in with an OpenID- Site fetches OpenID URL looks for X-XRDS-Location- Site parses XRDS-Simple doc to discover available APIs
Site tries to access contacts API gets a 401- WWW-Authenticate response header specifies OAuth- OAuth Discovery (via XRDS) provides OAuth endpoints
Site sends user though OAuth flow to grant access- User returns to site with authorized access token- Site can now access users’ contacts data via API + token
Performance Challenges
Minimizing round trips- Discovery, Association, OpenID, OAuth, etc.- Combining steps vs. small pieces loosely
joined- JSON-RPC in OpenSocial (batching API calls)
Caching: freshness vs. performance- Policies for how long to store personal data- Social Graph API: cached web crawl- Server-alerted notifications
Performance Challenges (cont.)
Pull vs. push: aggregating activity- Polling is easy but inefficient & doesn’t scale
(1000 users every 15 min > 1 hit per sec)- XMPP & Gnip: receive update notifications
Integrating 3rd party content- Server-side (proxied) vs. client-side (JS
onload)- Iframe vs. inline- New techniques: XFBML, Caja, etc.
