vsbabu.org

Simple MongoDB+Java example

2010-03-02T15:03:54+05:00

MongoDB is pretty slick for ease of use and scalability. As part of figuring out how to interface with MongoDB, I wrote a simple Java class that gives you an idea about how to create a collection and do CRUD on that. See below. Quite a bit of information is available on the web, but I thought a sample that shows off all the basic things will be useful. Good link - notes from a production mongoDB deployment

Cisco's new urbanism

2010-02-21T11:17:41+05:00

Fast Company's article about Cisco's vision for New Songdo is a fascinating read on smart cities. Perhaps all connected, with all the apartments being able to do lot with network via great functional phones feeding off mobile platforms?

Labelling in Outlook 2003 ala Gmail

2010-02-21T11:01:21+05:00

I found that moving mails into project folders, when the mails are still on an open topic takes too much time. Gmail's "label" idiom really helps in this situation. Turns out we can do that with Outlook 2003 too with some small macro work. First, see my entry on how to put macros and arrange toolbar in Outlook 2003. Then add the following macro to the module. Duplicate the second subroutine to as many as you've categories and then put toolbar entries for each of those. I think you should be able to do with less than 10 categories. At times you may get mails on an old subject, which you can just read and act and archive directly without tracking it.

Sub SetCategory(strCat As String)
   Dim Item As Object
   Dim SelectedItems As Selection
   Set SelectedItems = Outlook.ActiveExplorer.Selection
   For Each Item In SelectedItems
   With Item
    .Categories = strCat
    .Save
    End With
   Next Item
End Sub

Sub SetCategoryAdmin()
    SetCategory ("Admin")
End Sub

Quick Bazaar on Windows over SSH

2010-01-09T09:05:56+05:00

Quick notes on how to set up a version control system using Bazaar with just SFTP and Windows client.

Get a Unix/Linux machine that you've an account and that supports SSH.
Create a directory, say /home/loginid/repository
On your Windows machine, download pageant.exe and puttygen.exe (at a minimum) from PuTTy site.
Start puttygen.exe, generate your private and public key pair. Save private key somewhere. C:\Documents and Settings\\.ssh\id_rsa is a good choice. Exit puttygen.exe.
In your server, make a .ssh directory, create a new file called authorized_keys, paste the public key into that file without any line breaks.
Start pageant.exe. Right click on the icon (terminal with a hat) on the system tray, add key and choose the private key file.
Download and install Bazaar Windows version.
Start it Bzr in command line.
Create the remote repository like bzr init sftp://username@remote/home/loginid/repository
Create a local directory, create a repository there too.
Add some files to local repository.
When you want to push it up to remote, do bzr push sftp://username@remote/home/loginid/repository

For more info, read Bazaar doc.

Do not use GET for form processing!

2009-11-26T18:17:45+05:00

I thought everyone knew this. But recently I went to a site -- that is written by really smart Unix guys -- and was shocked to find that every single form is posted via "GET". Not "POST". This includes login form, billing information form (yes, the one with your credit card#) etc. It is absolutely insecure. Yes, the server is under HTTPS, but that is of no use here.

Why is it insecure? When you do a GET all the parameters are in the URL, in plain text. And the URL gets stamped in your browser history, web server access logs (we may be able to assume that the server is reasonably secure) and more scarily, in the logs of any proxy servers that are in the route.

Portable development links

2009-11-12T18:47:07+05:00

Wish I had this 10 years ago

2009-11-09T13:14:55+05:00

Pipe Viewer via IBM dW

In 1995, I got into a data warehouse project and all the ETL was through some bunch of shell utilities followed by sql*loader. This certainly would've helped!

SVN client over SSH to remote Unix server from Windows

2009-11-05T19:20:41+05:00

I needed to get a quick way to work with a personal version control system accessible from multiple computers running Linux or Windows. Ideally, I'd have liked to use Mercurial (light, easy, no great GUI available) or Bazaar (thicker, slower, good renaming capabilities, just about the best GUI available) or Git (fast, not a bad GUI, portable MSYS port is pretty good). However, my hosting provider provides only CVS or Subversion and I didn't want to install any of the above ones from source under my account. Nor do I want to run any server for this. Things should work with plain SSH. Initial approach was to create an SVN repository on the server and then access this from my computers using SSH. I tried getting svn+ssh pull for all of these above and couldn't get to work quickly enough on my Windows XP box. Had to then settle for an SVN client. Turns out that it is little tricky. Given below are the quick steps I followed to get this working.

Just a personal preference - I don't prefer using any of the Tortoise*GUIs. GUI as such is fairly nice, but I don't generally like installing shell extensions on Windows. Ideal solution for me would've been the ability for any of these to init a repository on a remote filesystem by SSH - couldn't find it out though.

Associate filetypes to VIM

2009-11-02T06:42:40+05:00

This has to be the best VIM tip for Windows - Windows File Associations. For example:

assoc .otl=outliner ftype outliner=c:\tools\vim\vim72\gvim.exe --remote-silent "%1"

Google Visualizations quick start

2009-10-26T10:38:27+05:00

Pretty nice article at Jeez.eu: Google Visualizations From A To Z. Explains how to use Google's json apis, get data from spreadsheets etc. With HTML5's client database, this should open up thoughts about some interesting small dashboard applications for the iPhone.

Nikon Coolpix 2500: White Balance Gone Outdoors

2009-10-24T15:23:47+05:00

I've an old Nikon Coolpix 2500 digital camera. It has just 2.0 Mpixel and 3x Zoom - really low end compared to standards these days, but I really like this. A month back, while driving down hills, took couple of photographs. Third one onwards, it just started showing up photos awash with white color. This only happens outdoors. Didn't feel like throwing out this camera - so tried lot of different stuff and chanced upon a solution. Just change the scene settings to Close Up and picture quality to FINE (default is NORMAL). It worked for me. Thought of posting this, in case it helps some one.

Also, I love this camera because of its handy size, lot of memories and also because it has a swivel lense - great for taking self portraits or when you don't find any one around to take your own photo!

SCM backed blogging - part II

2009-09-22T20:20:14+05:00

H3rald.com has a very comprehensive writeup about what I blogged earlier - SCM backed blogging. Lot more config to do, but you got lot more power. Definitely stuff I want to look into for this site.

Austerity?

2009-09-15T19:25:34+05:00

Everyone in the majority partner of ruling UPA, Congress(I) is into an austerity drive now.

Finance Minister requests External Affairs ministers to stop paying their own money on the accomodation they preferred. Media puts another spin on it by claiming FM actually forced them to move out!
Party President travelled by economy class, shaming another first-time MP to move down from business class to economy, while in flight.
General Secretary, who also happens to be the son of the Party President, travel by Train.

Hardly any of these are newsworthy, but there are a whole lot of news-starved channels that keep pushing this up the charts.

Most Indians know what happened to Bihar - when the ruler used bicycle as the mode of transport. Development happened at snail's pace. Perhaps this is current Government's way of warning us that the progress now will be proportionally slower - may be at the pace of a bicycle?

If the idea is to cut down wasteful expenditure, here are a whole bunch of other ways.

Quick Start Grinder - Part V

2009-09-10T06:15:33+05:00

After a run, you will need to analyze your data. Grinder console gives real time graphs, but I find getting the results into an Excel/OpenOffice spreadsheet and then going over it much easier. After your runs, look into the log directory for files named out*.log. These are CSV files that can be imported into any spreadsheet program easily. I've attached a template below into which you can paste the raw data and see the results. Note that I consider only 100 rows - very unrealistic since you will have thousands of records! I did this so that the file size is small. You can change the formulas where it says row 100 to row whatever you want. Also note that some formulas are array formulas - they are surrounded by curly braces - you need to press CTRL-SHIFT-ENTER after updating such formulae.

Quick Start Grinder - Part IV

2009-09-09T06:15:00+05:00

We will use the recorder that came with Grinder to record a test script.

Parts I, II and III of the series.

Step 1: Start and configure the recorder

Start it by running bin\startProxy.cmd. Change your browser setting to route the data through this proxy. Note that if your setup is behind another proxy, you need to pass -httpproxy command line option to the proxy.

Step 2: Start Recording

When you started proxy, a small Java dialog box would've come up. It takes some time to come up and quite possibly is behind your other windows. In that, you can add comments on what you are about to do. These comments are then preserved in the generated code.

So, let us add a comment @@@Getting google search page. Now, go to Google using your browser. After the page loads up completely, add a comment @@@Search for GRINDER. Now, type GRINDER in the search field and hit submit. Wait till the results come back. After the results are loaded, press Stop on the console to exit the recorder.

Look at the batch file to see where exactly are you keeping the generated file. Open it up in an editor. Few things you can notice are below.