N Rao Lakkakula’s Blog

1.  You have IIS and ASP.NET 1.1 running OK. Now you want to run ASP.NET 2.0 for one webfolder with 1.1 running remaining site. You started getting “Failed to access IIS metabase”.

Solution :  Run aspnet_regiis in asp.net 2.0 folder

C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727> aspnet_regiis -ga ASPNET

Then reset IIS

(more to be added soon….)

I been still surviving on IE6 until recently (as I use most of the time Opera or Firefox, I never bother to upgrade IE). But as I was playing with Silverlight, I need another browser to test my silverlight applications other than Firefox2. Upgrade is painless (you need to restart though at the end).

 After that, any links from my  Yahoo messenger were not working… same the case with Visual Studio 2005/2008…. I guess infact any attempt to launch a webpage from outside the browser was unsuccessful….. 

How to fix it….. my first guess was may be IE7 deleted or moved IE6 executable (Not replaced….as it wont be problem)…… and all these applications keep trying to lookup IE6 ………..  

Well…. I was wrong……  what happend was … IE6 was set as default browser at the time IE7 was installed and IE7 is not set automatically as default browser…….may be it asked me….I dont remember….. so all these applications are trying to launch default browser app…….without much success………..

So to Fix, simply launch IE7…. go to Tools –> Internet Options —> Programs  and Make IE7 as default browser……. that should fix all these broken links…………

I haved tried Yahoo Pipes sometime back when it was beta.  Popfly is Microsoft’s stab at creating mashups. Mashups allows you to connect multiple data sources to display units visually without any coding.

Popfly requires Microsoft SilverLight runtime ( Microsoft version of Adobe brought Macromedia’s Flash Player) to be installed to create mashup and also to view it. You also need windows live account.

My first test using IE 6 was not pleasant with blurry ghosty images whenever you move over any of the controls.  Also I didnt see any output when clicked on Preview.  You could see a popup warning saying “you are not using  IE7 or Firefox 2.0. ..your expereince may vary”. My second attempt with Firefox 2 is lot better. It worked smoothly (though I had trouble installing silverlight on Firefox. It ended up the problem is not with silverlight but NoScript addon… NoScript has a setting to forbid Silverlight for untrusted sites and some reason popfly is considered as untrusted site).

Also note that Opera wont work as silverlight is not supported on Opera browser. I use opera for most of the dialy browsing so it would be nice if silverlight support comes for opera in future.

Overall experience with Popfly is good and is bit faster than Yahoo Pipes (atleast when Pipes was beta). Popfly also makes creating template based webpage easier and quick and add as many as mashups embedded in that page.

Look at a simple mashup and webpage I did at http://www.popfly.ms/users/siri/myhomepage

Step1 : Install Ruby

Download Source ruby-1.8.5.tar.gz

$ tar -xvfz ruby-1.8.5.tar.gz

$ cd ruby-1.8.5

$ configure

$ make

$ make install

Step 2: Install Ruby gems

Download rubygems-0.9.4.tgz

$ tar -xvfz rubygems-0.9.4.tgz

$ cd rubygems-0.9.4

$ ruby setup.rb

Step 3: Install Practical Query Analysis

Download pga gem

$ gem install pqa-1.6.gem

Step 4: Configure PostgreSQL 

In postgresql.conf file, makesure these settings are on

log_statement  true

log_duration   true

log_pid        true

Restart PostgreSQL to make these changes in effect.In my case postgresql is setup as a service to start at boot. so restarting is easy.

service postgresql restart

Step 5:   Use PQA to anlayze log

pqa -file /path/to/your/logfile -normalize -top 5

To generate a HTML Report

pqa -file /path/to/your/logfile -normalize -top 5 -format html > /tmp/myReport.html

Thats it!. You could find slowest queires, most run queries and other cool stuff from this great tool.  you could out details and detailed documentation at http://pgfoundry.org/projects/pqa/

Problem : How to access my files on Linux Box from my Windows XP pc. But I dont anyone else access those.

Step 1: On Linux Box

a) Install Samba Server (If not installed)

Start Package Manager by going to Applications -> Add/Remove programs

Choose “Servers” and make sure “Windows File Server” is checked. If not check and Click Apply. It will download and install samba and dependencies.

b) Configure Samba

Launch Samba Configuration screen

System ->  Adminstration -> Server Settings -> Samba

Then that screen

Preferences -> Server Settings

In ‘Basic’ , Section choose a unique name for your share

In ‘Security’ Section  choose  ‘User’ and make sure ‘Encrypt Password’ is’Yes’ and ‘Guest Account’ is ‘No Guest Account’. There are usualy default options already selected

Then  ‘Preferences’ -> Samba Users

Here select your linux system user name and choose a username for windows ( I chose same name as linux user but its upto you… say you choose linux user is ‘bob’ and name given for windows user name  is ‘David’ and password is say ‘ Hillary’….. this passwor NEED NOT be your linux password or any other password you use on windows…its just a password for this share for David……)

c) Now add a ShareIn Samba Server Configuration Screen ,  Select ‘Add Share’ and Choose directory you want to access from windows…. and give a some description…….

Then  in Access Tab, select “Only allow access” to ‘David’

d) Now Start Samba Server

Launch Services Configuration by selecting

System–> Administration –> ServerSettings -> Services

In lefthand side, make sure to check ’smb”… it would start the smb and other required services

e)  Change Firewall Setting to allow Samba to be accessed

Launch firewall settings by selecting

Sytem -> Administation -> Security Level and Firewall

Then in trusted Services, Select ‘Samba’ and click Ok

Step 2: On Windows Box

Now access you share using VNC name……   \\yourlinuxboxname or IP\  it prompts you for userid password…..   use ‘David’ and ‘Hillary’……  thats it!

InstantRails is a Windows Package for rails learners to get started. It has pretty much everything to run rails (Ruby, rails, mysql server, and even PHP for mysql admin  and finally apache to proxy requests to mogrel).  I forgot…. it has a IDE (RadRails) bundled too..   Check out InstantRails

Now there is similar entry for Linux guys…. LinRails.  It also has everything need to get started( ruby, rails, mysql) exept Webserver though. So you could use builtin mongrel or webrick.  Try linRails

Wait… Its not one of many arguments over which one is better.  Both are excellent open source database systems  with rich set of features competing commmercial databases. (it look like MySQL has more marketing power than postgres though….) . The point I want to make is how both are different.  I been using Postgresql from almost 5 years.  When we tried to pick between MySQL and Postgres back then, I picked Postgresql as it has support for Foriegn Keys, triggers and stored procedures. So in the last five or so years when people asked me why Postgres over MySQL, I could proudly point to those features MySQL lacked. But NOT anymore!  Looks like MySQL 5 has all these covered. Now it has support for Views, Stored Procedures and Triggers.  ( See http://dev.mysql.com/doc/refman/5.0/en/mysql-5-0-nutshell.html)  More over they added more features from MaxDB (SA- DB from MySQL AB) like Event Scheduler in 5.1 version.  So now its purely personal preference of which one to pick.