frognibble

The title of the blog post implies that Tornado has support for sessions. This is not the case. The author of the blog post is benchmarking his own extensions to Tornado.

Not only did the author opt-in, there's also a way to opt-out. There's a big X next to the location on the compose form. Clicking the X removes the location.

It's common enough that Gmail has a feature to allow blocking the chat feature and not all Gmail. http://mail.google.com/support/bin/answer.py?hl=en&answe...

Brett Taylor discusses this issue in his tech talk on Tornado (http://bret.appspot.com/entry/tornado-tech-talk). He uses a hybrid approach: Use synchronous programming when requests block for a short time (fetching data from local db or memcache) and async programming when something blocks for a long time (calling out to third party services, long polling requests).

He does not go all async because programming with callbacks or deferreds is more complicated than straight line synchronous programming.

Brett also mentions that the instances of the server are created once and reused. He does not fork an instance of the server per request.

Your understanding is correct. Multiple requests can be active in a single instance of the Tornado server if the request handlers are written in an async style. The chat example included with the Tornado source demonstrates this feature.

Clojure programmers often work with logical lists called sequences. Arrays, maps, lists, sets, Java collections and many other types provide access to their elements as sequences.

Here's the example from the article written using the Clojure thread macro:

(-> netstat_n (grep "tcp") (awk 5) sort uniq_c sort_n print)

A cooperative is a group of people united voluntarily. A city is not voluntary (yeah, you can move. but it's not always possible or convenient until we have seasteading).

Variable bindings in Erlang are immutable to support the pattern matching. If variable bindings were not immutable, then Erlang would need syntax to distinguish between free and fixed variables in a pattern. The "=" in Erlang is pattern match, not assignment. Erlang could make bindings mutable without impacting the concurrent nature of Erlang because values would still be immutable.

This blog post describes why Winer does not like PubSubHubBub: http://brad.livejournal.com/2405147.html

Hewitt's criticism does not apply directly to Facebook. Facebook does not act as a gatekeeper. Facebook does not require approval or review before launch and operation of an application.

Rich Hickey picked the name Clojure partly because the name is easy to search for.

It was called Closure before Rich announced Clojure to the world.

Good point. You probably can use the libraries from Scala. In any case, you wouldn't be using Scala's concurrency features.

Clojure offers three concurrency mechanisms: agents, atoms and refs. Agents are atoms are very easy to use and understand. They are no more complicated than Scala's actors.

Clojure's refs are more complicated than Scala's actors, but Scala has no similar feature. If a Scala programmer needs the functionality in Clojure's refs, then the Scala programmer must use plain old Java concurrency.

I recommend reading this comparison of protocols before investing time in rssCloud: http://code.google.com/p/pubsubhubbub/wiki/ComparingProtocol...

I wonder who funded the study that shows that Chrome is less secure than IE. I hunted around, but could not find any indication about who paid for it.

XMPP is defined in two RFCs. RFC 3920 specifies the low level transport between servers and clients. Wave uses the server to sever transport defined in RFC 3920. RFC 3921 specifies messaging and presence. Wave ignores RFC 3921.

Perhaps there's no reason for a Google specific Java style guide because the Java style guide from Sun is pretty good.

According to the Tornado documentation, FriendFeed runs many instances of the Tornado server. If the number of server instances is greater than the number concurrent requests, then there's no problem with blocking calls. I personally find synchronous code easier to write/debug/understand than Twisted deferred.

See http://www.tornadoweb.org/documentation#running-tornado-in-p... . FriendFeed uses nginx as a reverse proxy to run several instances of the Tornado web server process. Each process has its own GIL.

Perhaps there are many alternatives because they all have problems.

There are several async programming libraries for Python including Allegra ( http://laurentszyster.be/blog/allegra/doc/ ), libevent-python (and other libevent bindings to python), the standard asyncore module and more. Why should Facebook use Twisted instead of one of these other libraries?

It's not obvious to me that this is a win for Tornado users.

There's a cost to adding a dependency on Twisted. It's one more thing to download. There's more code to understand when something goes wrong. And so on.

What are the benefits to me as a web programmer? If I understand correctly, my application will work as it did before. If that's true, then Twisted did not add any win for me.

You probably win because your patent has broad claims covering all 40 hour batteries. It does not matter that I know how to make them and you don't.

Google Reader adopted PubSubHubBub. PubSubHubBub is similar to RSSCloud, but fixes many issues with RSSCloud.

Nate Silver says that the analysis is flawed: http://www.fivethirtyeight.com/2009/06/statistical-evidence-...

Their implementation of all things Jingle came in advance of any specification, so it's not fair to call it NIH. See this comment for more info: http://senko.net/gmail-videochat-the-good-the-bad-and-the-ug...

This happened in late 2005.

Reddit is a community. FriendFeed is many communities.