Random Bits

Parking my motorbike out in the cold for good part of winter had resulted in a frozen clutch. As a result clutch could not disengage the transmission and so a gear shift caused a jerk and halted the bike. Thanks to a quick tip from Action Sports and help from CJ, this was fixed!

Grip the front wheel against the  parking curb and then holding both the brakes, shift the gear on slightly high throttle.

Note: Exercise caution while attempting this! At your own risk.

Today I got up to the sound of an explosion! Then I slowly walked into the living room hoping to see the main door still intact. It was still standing fine, so no burglars there. I looked around and found everything intact - but for some roaches running helter skelter, much to my annoyment. So I tried to convince myself that I might have got into some kind of trouble in my dream, ending in an explosion. With this reasoning, I got into my morning chores, still wondering back of my mind about the explosion.

Later when I was about to leave the apartment, guess what, my roommate’s cycle slowly collapsed. Yes the “explosion” was a busted bike tire - taking the tally to 5 flat tires among 3 bikes!

Nov 12, 2008.

In the Fall 2008 IAP poster presentation contest I presented my on-going research on “Capacity proportional unstructured p2p networks”.

This graph was generated using circo, a tool part of the graphviz package. The legend and the graph were generated separately and merged using paint. The graph represents simulation of a heterogeneous P2P network.

A Talk given by Ian Pratt in Usenix 2008 on goals and challenges of virtualization and how they are handled in Xen. Couple of interesting snippets from the talk:-

• Live relocation - Mechanism for moving a virtual machine from one physical server to another. It performs iterative memory transfer between machines using an intermediate dirty log file for each iteration. The changes in the log file are transferred in next iteration. This would gradually reduce the size of the dirty log file to a point where it is small enough to make the switch over with negligible downtime.
• Virtualization of mobiles - To provide isolation between different types of applications running on mobile phones. For example we can have 3 VMs on a mobile phone one each for running - core radio services, vendor shipped content and user downloaded content.

Ian Pratt, a senior lecturer in University of Cambridge Computer Laboratory stresses the importance of making the university projects open source and pursuing them beyond an academic paper. He acknowledges the challenges faced in taking Xen from a research project to a production quality software as a humbling experience.

This site now provides GWebCache service at http://gwc.chandanr.net/skulls.php. It can be used to bootstrap Gnutella (Limewire, Morpheus) and Gnutella2 (Shareaza) networks. I am using the Skulls Multi-Network Web cache system for this service.

Related Info:- Gnutella Web cache scan report

The “real” CLI for windows. Unlike our favourite shells like bash where output of a command is text, PowerShell deals with .NET objects. This makes pipe’ing etc very convenient. For example we can do things like:-

• PS C:\Users\Chandan> ps | Where-Object {$_.Handles -gt 1000}

Handles NPM(K) PM(K) WS(K) VM(M) CPU(s) Id ProcessName
——- —— —– —– —– —— — ———–
2313 0 0 848 8 4 System
…

• PS C:\Users\Chandan> ps firefox | format-list

Id : 3432
Handles : 883
CPU : 369.8315707
Name : firefox

• PS C:\Users\Chandan> (ps firefox).get_Id()

3432

• PS C:\Users\Chandan> (ps firefox).ProductVersion

2.0.0.12

With the exposure of objects, Powershell scripting is somewhat similar to application-level scripting supported by protocols like DCOP. Another very interesting feature in PowerShell is the concept of PSDrives and Providers which enable use of generic methods for navigating filesytem, registry, environment etc.

• PS C:\Users\Chandan> psdrive

Name Provider Root CurrentLocation
—- ——– —- —————
C FileSystem C:\ Users\Chandan
Env Environment
HKCU Registry HKEY_CURRENT_USER
…

• PS C:\Users\Chandan> cd env:

• PS Env:\> ls

Name Value
—- —–
Path C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files\Microsoft Visual Studio …
TEMP C:\Users\Chandan\AppData\Local\Temp
SESSIONNAME Console
…

Links

Video: Jeffrey Snover talks about Monad/PowerShell
Download PS

Why do good programmer have good memory?

Because they don’t forget to free

Tonight I watched the movie “Vantage Point“. The movie is on a terrorist attempt to assassinate the president of U.S.A. during a global peace summit. This movie is kind of unique as it is shown as a sequence of events as seen by 8 different characters, which collectively solves the conspiracy. Its a good movie but kind of gets boring with same events being played over and over again. It is like sampling a random process over multiple runs. All those boring repetitions could have been avoided by Poisson-like sampling of the events ;-).