Archive: February 25, 2006

Saturday, February 25, 2006

1. National Geographic: Many Dino Fossils Could Have Soft Tissue Inside:

   Soft-tissue dinosaur remains, first reported last year [blogged about here] in a discovery that shocked the paleontological community, may not be all that rare, experts say.

   The same features have emerged, and they are virtually indistinguishable from tissue samples from modern species... To demonstrate, Schweitzer showed two microscope-generated photographs side by side.
   
   "One of these cells is 65 million years old, and one is about 9 months old. Can anyone tell me which is which?"

     ¶ (0) Tags: [Evolution]

2. LtU: Hundreds of Impossibility Results for Distributed Computing.

     ¶ (0) Tags: [Distributed Computing, To Read]

3. AgentMine.com » Incompetent Russians. With a choice quote from King of the Hill

     ¶ (0)

4. Skatter Tech » How To Block Fasterfox Requests:

   User-agent: Fasterfox
   Disallow: /

   Fasterfox hasn't been the cause of this, but it appears it's meant to do the same type of thing. So, I'm blocking it. Oh, and with regards to that last post: best I can tell it's mostly Juno users using Juno Turbo. I wish I knew how to block it. Hmm, maybe Google Web Accelerator is also a culprit.

     ¶ (0)

Ajaxian » Troubles with Asynchronous Ajax Requests and PHP Sessions

Ajaxian » Troubles with Asynchronous Ajax Requests and PHP Sessions. Links to Marc Wandschneider's post explaining why you need to think about about possible race conditions with session data when using Ajax. Via Keith Gaughan, who posts some good comments on the Ajaxian thread about causes and possible solutions.

In short, server-side technologies like PHP don't let you lock access to your session across requests. So, you can A. try to do some complicated locking of your own on the server. B. store the critical session data in a MySQL RAM table (or some other equivalent) which AFAIK will handle the locking for you (of course, you're still not safe in this case unless you're careful). C. give the client knowledge of what changes the session state on a server that could lead to a race condition, and make sure those requests are serialized (i.e. get a response from the server before sending the next request).

Update: Harry Fuecks has a follow-up article on this.

Permalink | Comments? | Tags: Ajax, PHP | id 7971

07:18 (utc-6)
edited: 2006-02-27 20:42 (utc-6)