What is clustering

What is clustering

ØConnecting two or more computers together in such a way that they behave like a single computer.

Ø    Clustering is used for parallel processing load balancing and fault tolerance.

What is failover clustering

      A failover cluster is a group of servers that work together If one of the servers, or nodes, fails, another node in the cluster can take over its workload without any downtime (this process is known as failover).

Can be classified into….

•Active/Passive

•Active/Active

How to detect failure

•Push heartbeats

•Pull heartbeats

•Push heartbeats. For push heartbeats, the active server sends specified signals to the standby server at a well-defined interval. If the standby server does not receive a heartbeat signal over a certain time interval, it determines that the active server failed and takes the active role.

ÒPull heartbeats. For pull heartbeats, the standby server sends a request to the active server. If the active server does not respond, the standby server repeats the request a specific number of times. If the active server still does not respond, the standby server takes over as the active server.

Hardware requirements

•Servers: We recommend that you use a set of matching computers that contain the same or similar components.

•Network adapters and cable (for network communication): If you use iSCSI, each network adapter should be dedicated to either network communication or iSCSI, not both.

•Storage: You must use shared storage that is compatible with Windows Server 2012 R2 or Windows Server 2012.

Benefits

ÒScalability

ÒHigh Availability

ÒHigh Performance

advantages of cloud computing

Advantages of cloud computing

•        —Online form of computing
•   —Reduced cost
•   —More storage
•         Automatically updated
•         —Computing flexibility
•         —Mobility
•         —Shared Resources
•         —No downloads

      Online form of computing:-

•   ——Cloud computing is a online form of computing where users can access    applications via a browser, while the application is installed and stored on a          server.
•   Example:- Google Docs.

Reduced cost:-

•         —The main advantage of using cloud computing facility is that customers do      not  have to pay for infrastructure installation and maintenance cost.
• 
  
•   —It helps keep the cost down for both the users and website owners.

More storage:-

•   —It can hold more storage than a personal computer can. 
• —
•   —It takes away the need for the upgrading computer memory, which also helps keep the cost down for the companies and users. 

Automatically updated:-

•   —Owners no longer need to hire people to update more than one server, and it also helps the users who do not like to download updates for the software. 

Mobility:-

•   —It allows users to connect even without their own computers, meaning you can do your work from anywhere in the world as long as you have a internet connection and a computer access.

• —  So you can take your work with you anywhere.for example:on your wedding or vacations.

Shared Resources:-

•  —A key component of cloud computing is that companies share resources.—

•   —With cloud computing, this allows them all to have access to the resources via cloud computing.

Computing flexibility & No downloads:-—

•  —Computing Flexibility- It has more flexibility than other network computing systems and saves time plus money for people who are in a time crunch.
• —
•   —No Downloads- The users do not need to download anything, so that saves time and hard drive space for users. They can just log onto the network.

—

types of cloud computing

Types of Cloud Computing

—Public cloud

—Private cloud

—Hybrid cloud

Public Cloud: Computing infrastructure is hosted at the vendor’s premises.

Private Cloud: Computing architecture is dedicated to the customer and is not shared with other organizations.

Hybrid Cloud: Organizations host some critical, secure applications in private clouds.

What is cloud computing,Definition of Cloud Computing

Introduction

—Cloud computing is a technology that uses the internet and central remote servers to maintain data

and applications.

—All a consumer would need is just an internet connection and can start sending emails.

Cloud Services

•Software As a Service (SaaS)

•Platform As a Service (PaaS)

•Infrastructure As a Service (IaaS)

Software as a Service

—SaaS is the most widely known and widely used form of cloud computing.

—Highest-profile examples are Google's Gmail and Apps,  Yahoo , Google and Skype.

— Platform as a Service:- —It delivers virtualized servers on which customers can 

run existing applications or develop new ones without having to worry about maintaining the

operating systems, server hardware.

— —Infrastructure as a Service

—IaaS is designed to replace the functions of an entire data center.—

—This saves cost (time and expense) of capital equipment deployment .

Storing word,excel,image,pdf file in separate folders and database using php

file.php

<table align="center">
<form method="post" action="chk.php" enctype="multipart/form-data">
<tr><td>File Type</td>
<td>
<select name="upload">
<option value="pdf">pdf
</option>

<option value="image">image
</option>
<option value="document">document
</option>
<option value="spreadsheet">spreadsheet
</option>
</select>
</td>
</tr>
<tr><td>Upload your file here</td>
<td><input type="file" name="fileload"  value="Browse"/></td></tr>
<tr><td colspan="2" align="center"><input type="submit"></td></tr>
<?php
        error_reporting(0);

if($_REQUEST["msg"])
{
echo"<tr><td colspan='2' align='center'>$_REQUEST[msg]</td></tr>";
}
?>

</form>
</table>
</div>
</div>

</body>
</html>

chk.php

<!DOCTYPE html>

<html>

<head>

<title>php</title>

</head>

<body>

<?php

include("connect.php");

$uname=$_SESSION["user"];

$extn=$_POST["upload"];

$name=$_FILES["fileload"]['name'];

$file=$_FILES["fileload"]['tmp_name'];

$ext = pathinfo($name, PATHINFO_EXTENSION);

if($extn=="spreadsheet")

{

if( $ext == "xlsx" || $ext == "xlsm" || $ext == "xls")

{

$target="Excel/".$name;

move_uploaded_file($file,$target);

mysql_query("insert into data(Name,Excelfile) values('$uname','$target') ") or die(mysql_error()."error");

header("location:file.php?v=$uname");

}

else

{

header("location:file.php?msg=Select correct type"); 

}

}

else if($extn=="document")

{

if( $ext=="txt" || $ext=="csv" || $ext=="doc" || $ext=="docx" )

{

$target="Word/".$name;

move_uploaded_file($file,$target);

header("location:file.php?v=$uname");

mysql_query("insert into data(Name,Wordfile) values('$uname','$target') ") or die(mysql_error()."error");

}

else

{

header("location:file.php?msg=Select correct type"); 

}

}

else if($extn=="image")

{

if( $ext=="jpg"||$ext=="gif"||$ext=="jpeg"||$ext=="png" )

{

$target="Images/".$name;

move_uploaded_file($file,$target);

header("location:file.php?v=$uname");

mysql_query("insert into data(Name,Image) values('$uname','$target') ") or die(mysql_error()."error");

}

else

{

header("location:file.php?msg=Select correct type"); 

}

}

else if( $extn=="pdf")

{

if( $ext=="pdf")

{

$target="Pdf/".$name;

move_uploaded_file($file,$target);

header("location:file.php?v=$uname");

mysql_query("insert into data(Name,Pdf) values('$uname','$target') ") or die(mysql_error()."error");

}

else

{

header("location:file.php?msg=Select correct type"); 

}

}

else

{

header("location:file.php?msg=Type is not supported"); 

}

?>

</body>

</html>

virtual box and its advantages,disadvantages and features

b)VirtualBox

It is an X86 virtualization package which is now maintained by Sun Microsystems.

Virtual Box is a powerful virtualization product for enterprise as well as home use.It is not only an extremely feature rich, high performance product for enterprise customers, it is also the only professional solution that is freely available as Open Source Software under the terms of the GNU General Public License (GPL) version 2.

Presently, Virtual Box runs on Windows, Linux, Macintosh, and Solaris hosts and supports a large number of guest operating systems.

Features of VirtualBox

Portability

 VirtualBox runs on a large number of 32-bit and 64-bit host operating systems To a very large degree, VirtualBox is functionally identical on all of the host platforms.It uses same file and image formats.This allows you to run virtual machines created on one host on another host with a different host operating system; for example, you can create a virtual machine on Windows and then run it under Linux.

No hardware virtualization required

 For many scenarios, VirtualBox does not require the processor features built into newer hardware like Intel VT-x or AMD-V. As opposed to many other virtualization solutions, you can therefore use VirtualBox even on older hardware where these features are not present.  

Guest Additions

 The VirtualBox Guest Additions are software packages which can be installed of supported inside guest systems to improve their performance and to provide additional integration and communication with the host system. After installing the Guest Additions, a virtual machine will support automatic adjustment of video resolutions,accelerated 3D graphics and more.  

Guest multiprocessing (SMP)

VirtualBox can present up to 32 virtual CPUs to each virtual machine, irrespective of how many CPU cores are physically present on your host.

USB device support

 VirtualBox implements a virtual USB controller and allows you to connect arbitrary USB devices to your virtual machines without having to install device-specific drivers on the host. USB support is not limited to certain device categories.

VM groups

 VirtualBox provides a groups feature that enables the user to organize virtual machines collectively, as well as individually. In addition to basic groups, it is also possible for any VM to be in more than one group, and for groups to be nested in a hierarchy. In general, the operations that can be performed on groups are the same as those that can be applied to individual VMs i.e. Start, Pause, Reset, Close.

Advantages of VirtualBox

·         Snapshots

·         64-bit

·         Shared folders

·         Special drivers and utilities to facilitate switching between systems

·         Command line interaction (in addition to the GUI)

Disadvantages of VirtualBox

o    Poor performance with 32-bit guests on AMD CPUs. This affects mainly Windows and Solaris guests, but possibly also some Linux kernel revisions. Partially solved in 3.0.6 for 32 bits Windows NT, 2000, XP and 2003 guests. Requires 3.0.6 or higher Guest Additions to be installed.

o    Mac OS X guests can only run on a certain host hardware.

o    VirtualBox does not provide Guest Additions for Mac OS X at this time.

o    There is no support for USB devices connected to Solaris 10 hosts.

o    No ACPI information (battery status, power source) is reported to the guest.

o    No support for using wireless adapters with bridged networking.

what is vmware. Advantages,disadvantages and features of vmware

                               a)Vmware

This is a platform where you will get everything on Virtual machine. Whether you need a virtual Datacenter, virtual server or desktop, you will get on vmware.

VMware's desktop software runs on Microsoft Windows, Linux, and Mac OS X.

Advantages of using VMware

• Cost effective use of hardware
• Large portions of your production environment can be replicated
on a few servers
• Lower cost of hardware for the entire test environment
• Faster rollback during testing
• Test VMs can be deleted after they are not needed

Disadvantages of using VMware

• Requires that your staff have some basic VMware
skills
• VMs are not good for load testing if your production environment
is completely physical

Features of VMware

Infrastructure services

The set of components that comprehensively virtualizes server, storage and network  resources, aggregate them and allocate them precisely on demand to applications based on business priority.

Application services

The set of components that provide built-in service level controls to all applications running on VMware, regardless of application type or operating system.

RAM over-commitment

Increase memory utilization by configuring virtual machine memory that safely exceeds the physical server memory. For example, the sum of the memory of all virtual machines running on a server with 8GB physical memory can be 16GB.