Thursday 31 March 2011

Google Chrome: SPDY (Speedy)

So Google have now deployed their 'go faster' SPDY (Speedy) web page delivery protocol - which is not only in Chrome but also running on various Google services including gmail.

Google's performance figures on SPDY look good - and I think their figures are impressive. So if you want speeded up Google services then run Chrome!

There's all the dirt on SPDY here and of course they have a 'magic' URI/URL you can tap into your Chrome browser to see the internal stats:

about:net-internals

Monday 21 March 2011

So how radioactive is it in Tokyo?

Maybe you're wondering what the actual figures are - well you can watch them (uSv/hr) change (FYI I looked at it a week ago and it was 0.14uSv/hr - it is now 0.24uSv/hr) live on this live feed of a Geiger counter (a RADEX RD1503) located in Tokyo:

Live TV : Ustream
For the latest on the reactors check out daily updates from Japan's Atomic Industrial Forum.

Tuesday 8 March 2011

OSX environment variables

Where are those pesky things kept - as usual Apple like to keep us guessing....Whilst the folks at Stackoverflow provide answers:
  • ~/.profile, ~/.bashrc, (~/.cshrc, ~/.tcshrc) - depending on what shell you're running
  • ~/.MacOSX/environment.plist - More for GUI stuff
  • /etc/launchd.conf - used globally by launchd (can be set per process using launchctl setenv)
  • /etc/paths - just for setting the PATH

Tuesday 1 March 2011

Windows networking: interfaces

So have you ever wondered where Windows configures the some more obscure networking things like the length of its outgoing interface queue? (It's ok if you haven't ;) Anyway if you have then here's the dirt:
  • The actual maximum size of the queue (cf Linux's txqueuelen) is set in the registry:
    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{...your  GUUID here....}\ForwardBufferMemory which defaults to 50 packets (ok for 100Mbit Ethernet but not so good for Gigabit speeds...)
  • For the above config to work you need to enable router mode:
    HKLM\SYSTEM\CurrentControlSet\Services\Parameters\IPEnableRouter=1
  • In principle you can monitor the length of the output queue interface using this API
There's a various places that offer advice on improving performance like, Microsoft, and speedguide (win7). Windows 7 even provides special networking/scheduling support for multimedia apps.

Handy command line based Windows network tools: ipconfig, netsh