Clustering
A simple term which refers a bunch or group,
In computer terminology refers to bunch of computers.
High Availability
Name itself tells making something which is available all
the times.
We can't imagine a website like google or ebay going down
even for few seconds.There are organisation who can't afford even few seconds of downtime (planned or unplanned).So High Availability has become more important these days
For example we want to make a website/service highly available.
The website may use the following:
Database( some times more than one)
Webserver(some times more than one)
NIC Cards
Storage Connectivity
Internet Connectivity
Power Supply
List goes on.........
It indirectly means that we need to make all the above( sometimes even more) highly available.And its not possible to monitor all these manually, no one
knows when something is going to break or fault.
Here comes Clustering into picture, A group of computers
which are configured in such a way that they can overcome
failures for applications, etc and provide resilency
The load is distributed across different servers, and even
if any of the servers fails, the application is still
accessible via other cluster nodes
Generally a software which manages all these things known as Cluster Server.
A cluster compromises of redundent nodes to provide High
Availability, minimum configutaion requires 2 nodes.
Cluster Server software monitors all resources required to
run an application or service.
It checks the health of disks, R/W access, N/W Access, DB
Access, etc the way we configure it.
For example if something goes wrong say Some process/thread
related to Web Server is killed, it(Cluster s/w) immediately
detects that and gracefully shutsdown the application on
that node and starts it in another node ( redundent )
Major Vendors:
Symantec - Veritas Cluster Server
Sun - Solaris Cluster
Microsoft Microsoft Cluster Server
IBM - IBM Cluster
HP - HP Service Guard
To know more, check the following
http://en.wikipedia.org/wiki/Cluster_(computing)
Monday, January 25, 2010
Tuesday, January 19, 2010
Avoid Spam in GMail
Spam mails are annoying almost all netizens.
Sometimes it happens that we need to subscribe to some service (and see what it provides) and we guess/don’t know whether it may spam us.
But we are left with no other option than to give our e-mail and subscribe.
Here's a good idea to prevent such spam in GMail.
First know your Gmail Address
In GMail your address looks like your.name@gmail.com and no one else will have email address like you.r.name@gmail.com.
GMail has got nothing to do with (.), it ignores any dot (.) in email address.
Gmail doesn't recognize dots as characters within usernames, you can add or remove the dots from a Gmail address without changing the actual destination address; they'll all go to your inbox, and only yours.
For example, if your email address looks like
user.name1@gmail.com
Sending mail to following will come to your mail box only.
u.s.e.r.n.a.m.e.1@gmail.com
username1@gmail.com
u.s.e.r.n.a.m.e.1@googlemail.com
username1@googlemail.com
And even
username1+something@gmail.com this one refers to the same.
Avoiding Spam
If you need to subscribe to some abseexyzee.com and you suspect that it may spam you (and you want to try that), then follow these steps to avoid spam.
While giving your details in abseexyzee.com just give your email as username+test@gmail.com
username+test@googlemail.com
If abseexyzee.com starts sending spam they will be sent to username+test@gmail.com
Login to GMail at http://mail.google.com (use https for secure version) and Click on Settings top right.
Create a filter which deletes(depends how you create a filter) mails which come with that address username+test@gmail.com
Let us see how to create a filter in GMail
Creating a Filter in GMail
1. Click Setting in GMail
2. Go to Filters tab
3. Click on Create a new Filter
Just create a filter according to your requirements.
If you want to filter messages coming to username1+test@gmail.com
Specify that in to column, and others fields...
You can Test Filter using Test Search or Next Step to choose action
4. Select the option which you want to do.
Like delete, mark it as read; apply a label, etc, etc..
5. If a mail comes with username1+test@gmail.com it will be deleted (Depending on what you action you have chosen).
In this way you can avoid spam :-)
NOTE: abseexyzee.com is given only for illustration purpose, i have got nothing to do with this site even if it exists.
Sometimes it happens that we need to subscribe to some service (and see what it provides) and we guess/don’t know whether it may spam us.
But we are left with no other option than to give our e-mail and subscribe.
Here's a good idea to prevent such spam in GMail.
First know your Gmail Address
In GMail your address looks like your.name@gmail.com and no one else will have email address like you.r.name@gmail.com.
GMail has got nothing to do with (.), it ignores any dot (.) in email address.
Gmail doesn't recognize dots as characters within usernames, you can add or remove the dots from a Gmail address without changing the actual destination address; they'll all go to your inbox, and only yours.
For example, if your email address looks like
user.name1@gmail.com
Sending mail to following will come to your mail box only.
u.s.e.r.n.a.m.e.1@gmail.com
username1@gmail.com
u.s.e.r.n.a.m.e.1@googlemail.com
username1@googlemail.com
And even
username1+something@gmail.com this one refers to the same.
Avoiding Spam
If you need to subscribe to some abseexyzee.com and you suspect that it may spam you (and you want to try that), then follow these steps to avoid spam.
While giving your details in abseexyzee.com just give your email as username+test@gmail.com
username+test@googlemail.com
If abseexyzee.com starts sending spam they will be sent to username+test@gmail.com
Login to GMail at http://mail.google.com (use https for secure version) and Click on Settings top right.
Create a filter which deletes(depends how you create a filter) mails which come with that address username+test@gmail.com
Let us see how to create a filter in GMail
Creating a Filter in GMail
1. Click Setting in GMail
2. Go to Filters tab
3. Click on Create a new Filter
Just create a filter according to your requirements.
If you want to filter messages coming to username1+test@gmail.com
Specify that in to column, and others fields...
You can Test Filter using Test Search or Next Step to choose action
4. Select the option which you want to do.
Like delete, mark it as read; apply a label, etc, etc..
5. If a mail comes with username1+test@gmail.com it will be deleted (Depending on what you action you have chosen).
In this way you can avoid spam :-)
NOTE: abseexyzee.com is given only for illustration purpose, i have got nothing to do with this site even if it exists.
Sunday, March 22, 2009
GMail's new Feature "undo send"
Now, unsend emails
Gmail’s new feature ‘undo send’ enables users to stop emails from being sent within 5 secs
All those who tend to get themselves into unpleasant email “situations” every now and then can finally relax, thanks to an “undo send” feature launched by Gmail. Any user can enable the new feature in ‘Gmail Labs’ under ‘Settings’.
If a user feels that the email he just sent should be stopped, he or she should hit the ‘undo send’ button.
However, the user intending to stop the mail from being sent would get only five seconds to hit the button.
Gmail’s new feature ‘undo send’ enables users to stop emails from being sent within 5 secs
All those who tend to get themselves into unpleasant email “situations” every now and then can finally relax, thanks to an “undo send” feature launched by Gmail. Any user can enable the new feature in ‘Gmail Labs’ under ‘Settings’.
If a user feels that the email he just sent should be stopped, he or she should hit the ‘undo send’ button.
However, the user intending to stop the mail from being sent would get only five seconds to hit the button.
Thursday, August 14, 2008
Congrats Abhinav Bindra!!!
My heart felt congrats to abhinav bindra...
For making all indians proud...
You are india's pride..
Sunday, January 20, 2008
Peer to Peer Communication
What's P2P?
On the Internet, peer-to-peer (referred to as P2P) is a type of transient Internet network that allows a group of computer users with the same networking program to connect with each other and directly access files from one another's hard drives. Napster and Gnutella are examples of this kind of peer-to-peer software. Major producers of content, including record companies, have shown their concern about what they consider illegal sharing of copyrighted content by suing some P2P users.
Peer-to-peer Architecture
Peer-to-peer architecture is a type of network in which each workstation has equivalent capabilities and responsibilities. This differs from client/server architectures where some computers are dedicated to serving the others. Peer-to-peer networks are generally simpler but they usually do not offer the same performance under heavy loads. The P2P network itself relies on computing power at the ends of a connection rather than from within the network itself.
P2P is often mistakenly used as a term to describe one user linking with another user to transfer information and files through the use of a common P2P client to download MP3s, videos, images, games and other software. This, however, is only one type of P2P networking. Generally, P2P networks are used for sharing files, but a P2P network can also mean Grid Computing or Instant messaging.
Types of P2P Networks
Peer-to-peer networks come in three flavors. The category classification is based on the network and application.
Collaborative Computing
Also referred to as distributed computing, it combines the idle or unused CPU processing power and/or free disk space of many computers in the network. Collaborative computing is most popular with science and biotech organizations where intense computer processing is required.
Instant Messaging
One very common form of P2P networking is Instant Messaging (IM) where software applications, such as MSN Messenger or AOL Instant Messenger, for example, allow users to chat via text messages in real-time.
Affinity Communities
Affinity communities is the group of P2P networks that is based around file-sharing and became widely known and talked about due to the public legal issues surrounding the direct file sharing group, Napster. Affinity Communities are based on users collaborating and searching other user's computers for information and files.
How Peer-to-peer File-sharing Clients Work?
Once you have downloaded and installed a P2P client, if you are connected to the Internet you can launch the utility and you are then logged into a central indexing server. This central server indexes all users who are currently online connected to the server. This server does not host any files for downloading. The P2P client will contain an area where you can search for a specific file. The utility queries the index server to find other connected users with the file you are looking for. When a match is found the central server will tell you where to find the requested file. You can then choose a result from the search query and your utility when then attempt to establish a connection with the computer hosting the file you have requested. If a successful connection is made, you will begin downloading the file. Once the file download is complete the connection will be broken.
P2P Security Concerns
Copyright Infringement
Shared Folders
Adult Content
Content Filtering
Spyware
Viruses
Default Closing Behavior
Default StartUp Behavior
Know about Peer 2 Peer risks and how to use safely
P2P at Work
P2P is not only popular with home users but many small business have come to rely on this cost-effective solution for sharing files with co-workers and clients. P2P promotes the ease of working together when you're not physically located in the same office. In just seconds updated files and data can be shared with peers and confidential files can be blocked for security. Additionally, companies can also block access to Internet music and video files to assist in maintaining a work-oriented P2P network. Not only does this keep the company free and clear from legal issues regarding music downloading and sharing but it also keeps the corporate bandwidth usage down.
P2P Software
Here are some peer to peer file sharing software.
Ares Galaxy
Azureus
Bearshare
BitComet
BitSpirit
BitTorrent
CuteMX
DC++
eDonkey2000
eMule
iMesh
Kazaa
Kazaa Lite
LimeWire
Morpheus
Napster
Scour Exchange
Shareaza
uTorrent
WinMX
Previous Posts
Iphone
Push2Talk Services
Bluetooth Technology
Virtual Reality
Global Positioning Systems
On the Internet, peer-to-peer (referred to as P2P) is a type of transient Internet network that allows a group of computer users with the same networking program to connect with each other and directly access files from one another's hard drives. Napster and Gnutella are examples of this kind of peer-to-peer software. Major producers of content, including record companies, have shown their concern about what they consider illegal sharing of copyrighted content by suing some P2P users.
Peer-to-peer Architecture
Peer-to-peer architecture is a type of network in which each workstation has equivalent capabilities and responsibilities. This differs from client/server architectures where some computers are dedicated to serving the others. Peer-to-peer networks are generally simpler but they usually do not offer the same performance under heavy loads. The P2P network itself relies on computing power at the ends of a connection rather than from within the network itself.
P2P is often mistakenly used as a term to describe one user linking with another user to transfer information and files through the use of a common P2P client to download MP3s, videos, images, games and other software. This, however, is only one type of P2P networking. Generally, P2P networks are used for sharing files, but a P2P network can also mean Grid Computing or Instant messaging.
Types of P2P Networks
Peer-to-peer networks come in three flavors. The category classification is based on the network and application.
Collaborative Computing
Also referred to as distributed computing, it combines the idle or unused CPU processing power and/or free disk space of many computers in the network. Collaborative computing is most popular with science and biotech organizations where intense computer processing is required.
Instant Messaging
One very common form of P2P networking is Instant Messaging (IM) where software applications, such as MSN Messenger or AOL Instant Messenger, for example, allow users to chat via text messages in real-time.
Affinity Communities
Affinity communities is the group of P2P networks that is based around file-sharing and became widely known and talked about due to the public legal issues surrounding the direct file sharing group, Napster. Affinity Communities are based on users collaborating and searching other user's computers for information and files.
How Peer-to-peer File-sharing Clients Work?
Once you have downloaded and installed a P2P client, if you are connected to the Internet you can launch the utility and you are then logged into a central indexing server. This central server indexes all users who are currently online connected to the server. This server does not host any files for downloading. The P2P client will contain an area where you can search for a specific file. The utility queries the index server to find other connected users with the file you are looking for. When a match is found the central server will tell you where to find the requested file. You can then choose a result from the search query and your utility when then attempt to establish a connection with the computer hosting the file you have requested. If a successful connection is made, you will begin downloading the file. Once the file download is complete the connection will be broken.
P2P Security Concerns
Copyright Infringement
Shared Folders
Adult Content
Content Filtering
Spyware
Viruses
Default Closing Behavior
Default StartUp Behavior
Know about Peer 2 Peer risks and how to use safely
P2P at Work
P2P is not only popular with home users but many small business have come to rely on this cost-effective solution for sharing files with co-workers and clients. P2P promotes the ease of working together when you're not physically located in the same office. In just seconds updated files and data can be shared with peers and confidential files can be blocked for security. Additionally, companies can also block access to Internet music and video files to assist in maintaining a work-oriented P2P network. Not only does this keep the company free and clear from legal issues regarding music downloading and sharing but it also keeps the corporate bandwidth usage down.
P2P Software
Here are some peer to peer file sharing software.
Ares Galaxy
Azureus
Bearshare
BitComet
BitSpirit
BitTorrent
CuteMX
DC++
eDonkey2000
eMule
iMesh
Kazaa
Kazaa Lite
LimeWire
Morpheus
Napster
Scour Exchange
Shareaza
uTorrent
WinMX
Previous Posts
Iphone
Push2Talk Services
Bluetooth Technology
Virtual Reality
Global Positioning Systems
Subscribe to:
Posts (Atom)
