Bejegyzések

Bejegyzések megjelenítése ebből a hónapból: április, 2014

Firefox and testing concurrent web application

TL;DR: firefox won't start a request for an URL if a request is already being executed for that same URL. If you open http://example.com/foo, and it takes several seconds to complete, when you simultaneously open a new tab and enter the very same URL, the latter request WILL NOT BE SENT until the former has completed. If you ever need to make parallel requests for the same URL make sure you put some random query string in them, so the browser won't serialize requests for them. I was testing a concurrent web application written in Haskell, Yesod. I love Haskell and the Yesod framework, this combination gave me the best web development experience so far. I especially loved how easy it was to develop a simple web-based chat application by using TVars and TChans - variables and "channels" - basically message queues - to store state in a Yesod web application and pass messages between threads. I stumbled into a strange bug, and it took a good two hours of my life...

How to setup a raspberry PI as an IPv6 router with a SIXXS tunnel

Kép
IPv6? Internet Protocol version 6 is a network protocol that will soon replace  the current Internet Protocol version 4 - the protocol that runs the Internet, and has those familiar four-number addresses like 183.43.221.13 With IPv6 are coming a plethora of changes, probably the most end-user-alarming one will be the change in the address format demonstrated above. The four-times-one-byte address will be replaced by a eight-times-two-bytes address that looks like some fancy password from a bad computer movie. The new addresses will take the form of 4367:9987:a01b:0000:0000:0007:cafe:babe According to the simplification rules of IPv6 addresses, this can be written as 4367:9987:a01b::7:cafe:babe Since with a double colon you can jump through all of the all-zero address parts, and leading zeros can also be omitted.