My First FireFox Addon(Reliance NetConnect+ Data Usage)

Demo Reliance Netconnect Firefox Addon
Recently i bought a Reliance Netconnect+ Wireless Dongle. So far The service is good in my area .
My Data Usage Plan is 2GB day Usage and 10GB night usage.
To Keep myself from not going beyond the usage limit i keep on checking the reliance Website.
Initially i searched for any Reliance Netconnect+ Data Usage Addon in Mozilla Addons website.I didn’t found anything. So i started designing this addon . After 3 night sit-outs i completed a working addon. Now i have submitted it to the mozilla Addon developers site for review . Hopefully my addon will be reviewed within 3 days.
You can download my addon in the following Link
Download

Code Clean up is not done fully and as always known Comments are welcome 😉

Update:

Hi All,
Since firefox review team is taking more to complete the review of recent version 1.4 you can download it immediately in the following link

https://addons.mozilla.org/firefox/downloads/file/137145/reliance_netconnet_data_usage-1.4-fx.xpi?src=devhub

I thank everyone for their support , motivation and comments.

Release Notes:

  • Added capability to specify the billing date.
  • Decreased the number of decimal values from four to two.
Advertisements
Posted in Firefox Addon | Tagged , | 36 Comments

How to install Mysql Database and access it from Remote Client?

Mysql database is the most widely used database in the web.

Today i tried to develop an java web application in eclipse with MySQL as backend .

My Server setup goes as follows .

Mysql-server 5.1 version in fedora 14 VM.

To install mysql server in fedora  use the following command

yum install mysql-server

I installed toad for mysql in my windows machine and tried to access the mysql db from the toad . Unfortunately i am not able to access my server from my windows machine even though i entered server name as ip address of the fedora machine and i am able to connect to mysql from fedora terminal .

Finally i found that by default mysql allows only clients  from localhost and 127.0.0.1 .

To enable the access to the mysql server  for the clients which are from remote host(client) we need to execute the following commands.

mysql> CREATE USER 'monty'@'localhost' IDENTIFIED BY 'password';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'monty'@'localhost'   WITH GRANT OPTION;
mysql> CREATE USER 'monty'@'%' IDENTIFIED BY 'password';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'monty'@'%'   WITH GRANT OPTION;

The first statement will create an user with username as monty and password as ‘password’ and this user can access the databases only from localhost.

The second statement will grant all permissions for monty on all databases .

The third statement will create username monty with password as ‘password’ and this monty username can be used to access mysql server from any host or client machine. This is achieved by mentioning ‘%‘(Wild card for host) instead of localhost in the first statement.

The fourth statement will grant all privileges for monty in all databases .

Finally monty can access from localhost and also from all remote host.

For more info please refer the following official documentation.

http://dev.mysql.com/doc/refman/5.1/en/adding-users.html

Posted in Database, MySQL | Tagged , , | Leave a comment

How to install couchDB?

CouchDB is a NoSQL kind of Database from apache foundation.
CouchDB Comes under document store type NoSQL database.
For more details and different type of NoSQL database refer http://nosql-database.org/
Ok Lets get started ..
Here i will walk you through the installation of couchDB in fedora 14.

su -i
yum install couchdb

The above command will install couchdb database.
To start  and stop the coucdb you can issue the command
couchdb -b // -b flags will start your couchdb in backgroud mode.
couchdb -d // -d flag will stop the already started couchdb process

by default couchdb will start listening in the loopback ip address only with the port number 5984 .
To access the coucdb goto http://127.0.0.1:5984

The workstation in which i installed couchdb has a private address of 192.168.1.13. when i tried to access the couchdb with the http://192.168.1.13:5984  i am not able to access it  . The reason behind that is ,by default couchdb starts listening only to the loopback ip address 127.0.0.1. To make couchDB to listen in all the network interface  we need to edit couchDB’s defaulf configuration file located at

/etc/couchdb/default.ini
In the default.ini file comment out the line (directive) bind_address = 127.0.0.1 by adding semicolon at the start of line which finally looks like ;bind_address = 127.0.0.1
To restart the couchDB issue the following commands
couchdb -d // -d flag will stop the already started couchdb process
couchdb -b // -b flags will start your couchdb in backgroud mode.
After that you will be able to access couchdb over the network by specifying http://192.168.1.13:5984

CouchDB web based console ( Futon )
To access the web based CouchDB web based console goto
http://127.0.0.1:5984/_utils
There you can be able to create and manage the databases and values .

In the next post i will take try discuss on developing my first CouchDB based application.

Keep Your fingers croosed 😉

Posted in CouchDB, Database, NoSQL | Tagged , , , | 1 Comment

New Laptop Dell Inspiron N5010

Hi All,
After a long pause i am writing this blog post. I bought a new DELL Inspiron N5010 Laptop
The Rough Configuration is intel i5 M450 , 4GB RAM , 500GB hard disk , 1 GB ATI Radeon 550v Graphics card and other common stuffs.
You may feel like “You wrote this post just to tell this?” . No what i am trying to say is i will write more posts and interesting articles 😛 sooner or later . Keep your fingers crossed 😛

Posted in Uncategorized | 2 Comments

Virtualization An Overview

Virtualization allows multiple operating system instances to run concurrently on a single computer;
it is a means of separating hardware from a single operating system. Each “guest” OS is managed by
a Virtual Machine Monitor (VMM), also known as a hypervisor. Because the virtualization system sits
between the guest and the hardware, it can control the guests’ use of CPU, memory, and storage,
even allowing a guest OS to migrate from one machine to another.

[Never Mind if you didn’t get above paragraph 😛 ]

Here i would like to explain the different type of Virtualization which are currently popular in the market today.

1)Full Virtualization
2)Para virtualization
3)Hardware-assisted virtualization (Native virtualization)

Consider we have a bought a new server from IBM or HP or Dell and finally we named the bare metal as Host.
Next thing is normally we will install an Operating system over the bare metal(Host). In virtualization world this OS is called Host Operating System.
Now we are going to install the so called Virtual Machine Monitor(Consider it like a software ) over our Host Operating System.
Once we installed the Virtual Machine Monitor our server is ready to run multiple operating systems.
The OSes which are all installed over the VMM are called Guest OSes.

Full Virtualization
Full virtualization is a type of virtualization in which the guest operating systems need not to be modified.
That means the media(CD or whatever ) which we use to install operating systems over the bare metal can be used to install operating system over the Virtual Machine Monitor.

Technically the guest os do not aware of the fact that it is running over the virtualized environment all the instructions which are generated by the guest os have to be handled by the host os. So there will be more overhead which causes the performance degradation.

Performance wise full virtualization occupies bottom .
Software supports full virtualization are VMWARE Workstation ,Virtual Box ,VMWARE Server etc..

Para Virtualization

In Para virtualization the guest operating systems need to be modified(Called OS porting) . Only Ported operating sytstems can be installed as a guest os in para virtualization.
Software supports para virtualization.
XEN

Since the guest os is well aware of the fact that it is running over a virtualized environment it can able to communicate very easily with the host operating system. Though the guest know that it is running over the virtualized environment still there will be an overhead because all the instructions need to be passed through the host operating system.
Performance wise it stands in between the other two.

Hardware-assisted virtualization (Native virtualization)
The intel and AMD guys have came up with hardware support for the virtualization. In the above 2 cases everything is done by the Virtual Machine Monitor(Software). My old school teacher used to say that whenever an algorithm is implemented in hardware it will be 2 to 10 times faster when compared to implementation of the same algorithm in software.
Intel VT-x and AMD V are the initially released hardware support for virtualization(For Binary Translation).
Recently Intel and AMD released Intel-d and AMD-Vi for hardware support virtualization(For Directed I/O).
Software that Supports Hardware Assisted virtualization are KVM ,Vmware ESX server ,Vmware workstation XEN etc.
Not all the processor will support this virtualization. Only processor that has this technology can support. For details have to check the processor specifications.
For more
http://www.intel.com/technology/virtualization
http://sites.amd.com/us/business/it-solutions/usage-models/virtualization/Pages/virtualization.aspx
Performance wise Hardware assisted virtualization tops among the three.

Types Of Hypervisors
In the whole above context the guest OS is installed over the Virtual Machine Monitor and which in turn installed over the host operating system. In Virtualization world this is called as Type II Hypervisor.

Some people came up with new idea why do i need to install Virtual Machine Monitor(Hypervisor) over the host os instead of that they started to install it over the bare metal . This is called as Type I Hypervisor

For production environment a hypervisor with Type I and hardware assisted virtualization is recommended.

Advantages of Virtualization
1)A complete abstraction between the hardware and guest OS.
2)Server Consolidation(Data center Consolidation)
3)High Availability
4)Live Migration
5)Reduced power and cooling costs. and Lots More…

Virtualization is one of the big stepping stone for the cloud computing.

Posted in Virtualization | Tagged , , , , , , , , , | 3 Comments

BSNL Router WA3002G4 Port Forwarding With Virtual Servers

Here i like to share my experience with the great!! great!!! BSNL ADSL2+ Router and how i banged my head with that router 😛

While i am staying in coimbatore i am AIRTEL Customer . In their ADSL2+  Router under the NAT i have NAT Virtual Servers Link , Port Triggering  and DMZ.  I use Nat Virtual servers to do port forwarding to my system  so that i can play games host some servers like Apache , ftp in different systems on my LAN.

After myself shifting to chennai i bought BSNL Broadband Connection because of only reason that in my locality Airtel is not Available . To my bad surprise as usual i opened the router configuration page by typing http://192.168.1.1 . Under the NAT there is only DMZ no other links 😦 . I want the dam Nat Virtual Server  Setup . So i started to pondering how to do that.

Router Nat Page Without Virtual Servers Link

Some People recommended to put my Systems LAN IP in DMZ host . Thats really really not recommended because your are putting your system in big security risk unless you have really good Operating system level firewall .

Note : I am talking about DMZ host not DMZ Zone for further reading http://en.wikipedia.org/wiki/DMZ_%28computing%29

And also you cannot able to port forward different services to different servers in your LAN.

To know more about port forwarding www.portforward.com

Here is a how to do a portforward in BSNL WA3002G4 by using a Hidden Link

http://192.168.1.1/scvrtsrv.cmd?action=view

Virtual Servers

I dont know why that link is hidden from the users . And also i am wondering who hidden that from the end user whether the manufacturer UTStarCom or BSNL .

How i found that they have hidden the link . I sshed  the router and  It’s there to my surprise . have a look at the below picture 🙂

ssh

here is the how to to add a virtual server by using ssh

download Putty login with your username and password Go to NAT–> 1 Virtual servers –> 1 Add

addvs

Note : Internal Server IP Address Should be your LAN ip address

But i Request you to go for http configuration by using the link http://192.168.1.1/scvrtsrv.cmd?action=view for better understanding.

Posted in Router Hacking | Tagged , , | 25 Comments

How to monitor logs of network systems using syslog

This is a client server model. One system in your  network  act as a logs server used to monitor all the logs of other systems using  syslog (syslogd in aix) daemon .

Server side configuration(only linux can act as server , AIX cant afaik)

open /etc/sysconfig/syslog add -r (allow remote logging ) before -m

SYSLOGD_OPTIONS=” -r -m 0″

save and quit

service syslog restart

Client side configuration(linux and aix)

open /etc/syslog.conf

add the following line

*.*            @server ip address ( or server hostname)

save and quit

service syslog restart (redhat or cent linux)

refresh -s syslogd (for aix)

tail -f /var/log/messages (on server side)

Thanks to my Mentor  Mr. Senthil 🙂

Posted in system administration | Tagged , | Leave a comment