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Posts Tagged ‘cloud computing’

Overview of HADOOP

When we look into the structure of this framework , we find that it is divided into HDFS and MapReduce.
The two hands of Hadoop framework
i.e. HDFS and MapReduce are Hadoop Distributed File System- the storage hand and the processing hand respectively. This skeleton divides the total data into smaller blocks and circulate them in assemblage through the junctions called nodes in the network. The JAR is sent to the nodes where the data needs to be worked on. Here the nodes responsible for those data residing near them work faster in transferring them.

big-data
Hadoop  carries  four programs  of  study.

They  are :
-> Hadoop Common
-> HDFS
-> Hadoop YARN
-> Hadoop MapReduce

1. Hadoop common acts as the information centre that contains the collections of Hadoop libraries.
2. HDFS is the storage part of high band of frequencies.
3.The YARN organizes the properties that line up the user’s function in an assemblage.
4.MapReduce is the processor that processes all sets of data.

Hadoop is such a frame that can store and circulate huge data files without minimum error. Hence it is highly scalable.

1.This software costs very less for storing and performing computations on data in comparison with the traditional databases.
2.Accessing with different kinds of business solution data is done by Hadoop with ultimate comfort. It has been proving to be its best in decision making.
3.It helps in social media, emailing, log processing, data warehousing, error detection etc.
4. Since it maps the data wherever it is placed so Hadoop takes very less time in order to unfold any data. It hardly takes an hour to work on large petabytes of data. Hene, it is super fast.

Hence, the companies using Hadoop are able to gain far better insights. Whenever a data block goes from one node to another in the assemblage of the network, each  block gets copied to each node and even if the data is lost, we will always be having a backup copy of it. Hence, fault occurrence is really very low.

 

October 20, 2011 Leave a comment
Php

Image via Wikipedia

I’ve run into an error using an image resizing script by Victor Teixeira, which has worked wonderfully until I noticed an issue related to using the Featured Image uploader. If I a Featured Image, then attempt to re-insert a different image in its place I get this error:

function vt_resize( $attach_id = null, $img_url = null, $width, $height, $crop = false ) {

// this is an attachment, so we have the ID
if ( $attach_id ) {

    $image_src = wp_get_attachment_image_src( $attach_id, 'full' );
    $file_path = get_attached_file( $attach_id );

// this is not an attachment, let's use the image url
} else if ( $img_url ) {

    $file_path = parse_url( $img_url );
    $file_path = $_SERVER['DOCUMENT_ROOT'] . $file_path['path'];

    //$file_path = ltrim( $file_path['path'], '/' );
    //$file_path = rtrim( ABSPATH, '/' ).$file_path['path'];

    $orig_size = getimagesize( $file_path );

    $image_src[0] = $img_url;
    $image_src[1] = $orig_size[0];
    $image_src[2] = $orig_size[1];
}

$file_info = pathinfo( $file_path );
$extension = '.'. $file_info['extension'];

// the image path without the extension
$no_ext_path = $file_info['dirname'].'/'.$file_info['filename'];

$cropped_img_path = $no_ext_path.'-'.$width.'x'.$height.$extension;

// checking if the file size is larger than the target size
// if it is smaller or the same size, stop right here and return
if ( $image_src[1] > $width || $image_src[2] > $height ) {

    // the file is larger, check if the resized version already exists (for $crop = true but will also work for $crop = false if the sizes match)
    if ( file_exists( $cropped_img_path ) ) {

        $cropped_img_url = str_replace( basename( $image_src[0] ), basename( $cropped_img_path ), $image_src[0] );

        $vt_image = array (
            'url' => $cropped_img_url,
            'width' => $width,
            'height' => $height
        );

        return $vt_image;
    }

    // $crop = false
    if ( $crop == false ) {

        // calculate the size proportionaly
        $proportional_size = wp_constrain_dimensions( $image_src[1], $image_src[2], $width, $height );
        $resized_img_path = $no_ext_path.'-'.$proportional_size[0].'x'.$proportional_size[1].$extension;            

        // checking if the file already exists
        if ( file_exists( $resized_img_path ) ) {

            $resized_img_url = str_replace( basename( $image_src[0] ), basename( $resized_img_path ), $image_src[0] );

            $vt_image = array (
                'url' => $resized_img_url,
                'width' => $proportional_size[0],
                'height' => $proportional_size[1]
            );

            return $vt_image;
        }
    }

    // no cache files - let's finally resize it
    $new_img_path = image_resize( $file_path, $width, $height, $crop );
    $new_img_size = getimagesize( $new_img_path );
    $new_img = str_replace( basename( $image_src[0] ), basename( $new_img_path ), $image_src[0] );

    // resized output
    $vt_image = array (
        'url' => $new_img,
        'width' => $new_img_size[0],
        'height' => $new_img_size[1]
    );

    return $vt_image;
}

// default output - without resizing
$vt_image = array (
    'url' => $image_src[0],
    'width' => $image_src[1],
    'height' => $image_src[2]
);

return $vt_image;
}

Google apologizes, explains Gmail outage

September 4, 2009 2 comments

Matthew Borghese – AHN Editor

New York, NY (AHN) – Google’s popular, free e-mail service Gmail suffered an gmail_crashes313outage on Tuesday, prompting more questions about “cloud computing” at a time when the Internet search giant is trying to wean users off of their desktop workspace.

A technical error during a routine maintenance overloaded some servers on Tuesday, leaving users high and dry, according to Google Vice President of Engineering and Gmail “Site Reliability Czar” Ben Treynor.

The outage is a blow to Google, who is fighting a battle against Microsoft and others as it hopes to get more users to access and store more data online, versus on their own hard drives. With online office programs like Google Apps, the world’s leading search engine is taking aim at Microsoft’s popular Office suite. Google has also developed a web browser and operating system, which look to displace Microsoft’s famous Internet Explorer and Windows.

While Google touts the collaborative capacity of keeping business documents online, when there is a server outage like what was seen on Tuesday, there is no way to access that data. Still, unlike a hard drive crash or computer theft, no data stored by Google was lost yesterday – and the company is quick to admit fault.

“We know how many people rely on Gmail for personal and professional communications, and we take it very seriously when there’s a problem with the service,” Treynor said in a statement. “Thus, right up front, I’d like to apologize to all of you – today’s outage was a Big Deal,and we’re treating it as such. We’ve already thoroughly investigated what happened, and we’re currently compiling a list of things we intend to fix or improve as a result of the investigation.

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