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What is Leap Second - June 30, 2015 Leap Second & Internet !!!

Leap Second

A leap second is a one-second adjustment that is occasionally applied to Coordinated Universal Time (UTC) in order to keep its time of day close to the mean solar time. Without such a correction, time reckoned by Earth's rotation drifts away from atomic time because of irregularities in the Earth's rate of rotation. Since this system of correction was implemented in 1972, 25 such leap seconds have been inserted. The most recent one happened on June 30, 2012 at 23:59:60 UTC. A leap second will again be inserted at the end of June 30, 2015 at 23:59:60 UTC.

The UTC time standard, which is widely used for international timekeeping and as the reference for civil time in most countries, uses the international system (SI) definition of the second, based on atomic clocks. Like most time standards, UTC defines a grouping of seconds into minutes, hours, days, months, and years. However, the duration of one mean solar day is slightly longer than 24 hours (86400 SI seconds). Therefore, if the UTC day were defined as precisely 86400 SI seconds, the UTC time-of-day would slowly drift apart from that of solar-based standards, such as Greenwich Mean Time (GMT) and its successor UT1. The purpose of a leap second is to compensate for this drift, by occasionally scheduling some UTC days with 86401 or 86399 SI seconds.

Specifically, a positive leap second is inserted between second 23:59:59 of a chosen UTC calendar date (the last day of a month, usually June 30 or December 31) and second 00:00:00 of the following date. This extra second is displayed on UTC clocks as 23:59:60. On clocks that display local time tied to UTC, the leap second may be inserted at the end of some other hour (or half-hour or quarter-hour), depending on the local time zone.

A negative leap second would suppress second 23:59:59 of the last day of a chosen month, so that second 23:59:58 of that date would be followed immediately by second 00:00:00 of the following date. However, since the UTC standard was established, negative leap seconds have never been needed.

Because the Earth's rotation speed varies in response to climatic and geological events, UTC leap seconds are irregularly spaced and unpredictable. Insertion of each UTC leap second is usually decided about six months in advance by the International Earth Rotation and Reference Systems Service (IERS), when needed to ensure that the difference between the UTC and UT1 readings will never exceed 0.9 second. Between their adoption in 1972 and June 2012, 25 leap seconds have been scheduled, all positive; this will become 26 leap seconds at 23:59:60 UTC on June 30, 2015.

June 30 will be a second longer than any other day this year

A leap second needs to be added in 2015 to make sure the time on atomic clocks stays in sync with Earth's rotational time, but some Internet companies are dreading the day.

Earth's rotation has been slowing down by about two thousandths of a second every day. But atomic clocks, which are now accurate up to quadrillion of a second, don't change pace. While this situation isn't an immediate problem, it would eventually cause clocks to become so out of sync with Earth's rotation that they would read noon during the dead of night.

"Earth is slowing down over geological time, and that can lead to a problem when you've got a ton of clocks," Demetrios Matsakis, chief scientist for Time Service at the U.S. Naval Observatory, told Live Science. "What do you do when the day gets longer?"

The solution that the International Earth Rotation Service (IERS) came up with is to add a second every now and then to keep the standard atomic time in sync with Earth's time. This year, the extra second is scheduled for the midway point in the year, at 11:59.59 p.m. Coordinated Universal Time (UTC) on June 30.

This will be the 26th leap second added to a calendar year since the practice began in 1972. In the past, the extra second has messed with computer systems. The last leap second was added in 2012, and it caused problems for big companies like Reddit, LinkedIn, Gizmodo and FourSquare.

The problem is that during the leap second, the computer clock shows 60 seconds instead of simply rolling over to the next minute, or shows the 59th second twice. The computer sees a leap second as time going backward, Matsakis said. The machine registers this as a system error, and the CPU can overload.

Google, to skirt the problem, will add a millisecond to its servers every once in a while throughout the year. This way, the slowed-down servers don't notice when an extra second is slipped in. Another good way to avoid any trouble is to simply shut down a computer system for an hour or two around the leap second, Matsakis said.

But many programmers are oblivious to leap seconds, and this can also cause problems. The additional seconds happen so infrequently and so irregularly that it makes it difficult for computer companies to catch on to the problem. While Reddit, LinkedIn, Gizmodo and FourSquare will likely remember the lesson they learned three years ago, other sites that didn't experience any issues are likely still "blissfully unaware," Matsakis said.

But the leap second could put more than just computer systems at risk. It's a little over-cautious, Matsakis admits, but he said he would not want to be on board a plane during a leap second. The extra second has been known to interrupt GPS receivers, which could be a problem for pilots.

The year 2015 will have an extra second — which could wreak havoc on the infrastructure powering the Internet.

At 11:59 p.m. on June 30, clocks will count up all the way to 60 seconds. That will allow the Earth's spin to catch up with atomic time.

The Earth's spin is gradually slowing down, by about two thousandths of a second per day, but atomic clocks are constant. That means that occasionally years have to be lengthened slightly, to allow the slowing Earth to catch up with the constant clock.

But last time it happened, in 2012, it took down much of the Internet. Reddit, Foursquare, Yelp and LinkedIn all reported problems, and so did the Linux operating system and programs using Java.

The reset has happened 25 times since they were introduced in 1972, but the computer problems are getting more serious as increasing numbers of computers sync up with atomic clocks. Those computers and servers are then shown the same second twice in a row — throwing them into a panic.

If a computer is told to do an operation at the time that is repeated, for instance, the computer is unsure what to do. Or if an e-mail is received in that moment, it could find its way in the wrong bit of the server.

Last time, Google anticipated the problem and built a smart update, which it called "leap smear". It modified its servers so that they would add a little bit of extra time every time they were updated, so that by the time of the leap second they were already caught up with the new time. It said when it laid out the plan in 2011 that it would use the same technique in the future, when new leap seconds are announced.

The Leap Second & Its Impact. Let's Recall The Altea reservation and departure system

Time lords in Paris will add a leap second to UTC on 30 June this year. The last time they added a leap second to the world's clocks was on 30 June, 2012, extending UTC by an additional second.

One by-product of that was that they temporarily took down air travellers in Australia. The Altea reservation and departure system run by Amadeus, one of the largest computer travel reservation systems on the planet, couldn’t cope and crashed. For 48 minutes, passengers and staff at Qantas and Virgin Australia were thrown back into the 1990s world of manual check-in and delayed flights.

The reason? Altea ran a version of the Linux kernel that harboured a long-dormant Linux bug that meant the freeware didn’t recognise leap seconds.

The second the clocks ticked past midnight GMT, the bug awoke and took down Altea. 135 airlines had implemented the Altea reservation system by 2012 but the Australians were the first to go down once the clocks hit midnight.

Servers run by Mozilla, StumbleUpon, Yelp, FourSquare, Reddit and LinkedIn were also reported to have been hit by the same bug, meaning a lot of people couldn't post their “critical” status updates or restaurant reviews.

The problem was they all ran Linux, and back then the addition or removal of a leap second sent the system into meltdown – the system would deadlock.

The bug was found to affect kernels version numbers 2.2.26 to 3.3, inclusive.

Not that it was all Linux’s fault: Mozilla’s Hadoop and ElasticSearch Servers using Java were also taken down. A Java fix was quickly developed.

Since that inglorious day the kernel has been patched. Distro makers like Red Hat also released their patches to make sure the problem didn’t crop up again.

As for Amadeus, the giant it reckoned it had sidestepped the bug with a workaround that it had implemented within an hour of things going south.

An Amadeus spokesperson told The Reg it's monitoring very closely industry discussions on the new leap second and following best practice standards. "Planning is already in progress and we are preparing to ensure a smooth transition," the spokesperson said.

So in the era of Cloud Computing, the Leap Second on June 30, 2015, will impact the Internet System ??? A big question with no full proof answer !!! 

Geetika Technosoft Pvt Ltd - GTechnosoft Family Wishing All of You Very Happy & Prosperous New Year 2015

A Quick Overview - Apache Spark

Apache Spark

Apache Spark is an open source parallel processing framework that enables users to run large-scale data analytics applications across clustered computers.

Apache Spark can process data from a variety of data repositories, including the Hadoop Distributed File System (HDFS), NoSQL databases and relational data stores such as Apache Hive. Spark supports in-memory processing to boost the performance of big data analytics applications, but it can also do conventional disk-based processing when data sets are too large to fit into the available system memory.

Spark became a top-level project of the Apache Software Foundation in February 2014, and Version 1.0 of Apache Spark was released in May 2014. The technology was initially designed in 2009 by researchers at the University of California, Berkeley, as a way to speed up processing jobs in Hadoop systems. Spark provides programmers with a potentially faster and more flexible alternative to MapReduce, the software framework that early versions of Hadoop were tied to. Spark's developers say it can run jobs 100 times faster than MapReduce when processed in memory and 10 times faster on disk.

In addition, Spark can handle more than the batch processing applications that MapReduce is limited to running. The core Spark engine functions partly as an application programming interface (API) layer and underpins a set of related tools for managing and analyzing data, including a SQL query engine, a library of machine learning algorithms, a graph processing system and streaming data processing software.

Apache Spark can run in Hadoop 2 clusters on top of the YARN resource manager; it can also be deployed standalone or in the cloud on the Amazon Elastic Compute Cloud (EC2) service. Its speed, combined with its ability to tie together multiple types of databases and run different kinds of analytics applications, has prompted some proponents to claim that Spark has the potential to become a unifying technology for big data applications.

Happy Birthday Google.com !!!

How many people know the name of  Google.com ???
How many people use Google.com ???
How many people set their browser's Search Engine as Google.com ??? 


The answer is simple. Its Everyone !!!


But how many people know that today is the Birth Day of Google.com !!!


Yes, Google.com domain was registered exactly 17 years ago, on 15 September 1997 !!! 

The Who Is Detail :

Domain Name: google.com
Registry Domain ID: 
Registrar WHOIS Server: whois.markmonitor.com
Registrar URL: http://www.markmonitor.com
Updated Date: 2014-05-19T04:00:17-0700
Creation Date: 1997-09-15T00:00:00-0700
Registrar Registration Expiration Date: 2020-09-13T21:00:00-0700
Registrar: MarkMonitor, Inc.
Registrar IANA ID: 292

 Happy Birthday Google.com  !!!

A Brief About mPOS - Mobile Point of Sale

mPOS - Mobile Point of Sale

Before we know about mPOS - Mobile Point of Sale, we have to understand what is POS - Point of Sale. Point of Sale - POS or Checkout is the place where a retail transaction is completed. It is the point at which a customer makes a payment to the merchant in exchange for goods or services. At the Point of Sale the retailer would calculate the amount owed by the customer and provide options for the customer to make payment. The merchant will also normally issue a receipt for the transaction. The POS in various retail industries uses customized hardware and software as per their requirements. Retailers may utilize weighing scales, scanners, electronic and manual cash registers, EFTPOS (Electronic Funds Transfer at Point of Sale — is an electronic payment system involving electronic funds transfers based on the use of payment cards, such as debit or credit cards, at terminals located at points of sale.) terminals, touch screens and any other wide variety of hardware and software available for use with POS. For example, a grocery or candy store uses a scale at the Point of Sale, while bars and restaurants use software to customize the item or service sold when a customer has a special meal or drink request.

The modern Point of Sale is often referred to as the Point of Service because it is not just a Point of Sale but also a Point of Return. Additionally it includes advanced features to cater to different functionality, such as inventory management, CRM, financials, warehousing, etc., all built into the POS software. Prior to the modern POS, all of these functions were done independently and required the manual re-keying of information, which can lead to entry errors.

mPOS - Mobile Point of Sale in a single word, a "Dongle Plus Smartphone" innovation for modern POS system. An mPOS - Mobile Point of Sale is a smartphone, tablet or dedicated wireless device that performs the functions of a cash register or electronic Point of Sale (POS) terminal. 

mPOS implementations allow service and sales industries to conduct transactions in place, improving the customer experience and freeing up valuable real estate that would otherwise be dedicated to a POS counter. An mPOS can also be cost-effective, allowing a small business owner to conduct transactions without having to invest in an electronic register or pay someone to support the software. 

Any smartphone or tablet can be transformed into an mPOS with a downloadable mobile app. Typically, when the business owner registers the app, the vendor sends the business owner a card reader that plugs into the mobile device's audio jack. Some mPOS software vendors also provide optional hand-held docking stations (called sleds) that allow the mobile device to read barcodes and print receipts. 

Depending on the software, a mPOS can operate as a stand-alone device that's simply linked to the business' bank account or it can be an integrated component of a larger, legacy POS system. To protect cardholder data, customer data is encrypted and stored in the cloud -- not on the device.

Popular mobile POS vendors include PayPal, Square, Intuit and VeriFone. 

NOTE:   mPOS implementation requires Strong Security Awareness.  

Quick Reference Guide - CRUSH & Ceph

CRUSH

CRUSH (Controlled Replication Under Scalable Hashing) is a hash-based algorithm for calculating how and where to store and retrieve data in a distributed object-based storage cluster.

CRUSH is the pseudo-random data placement algorithm that efficiently distributes object replicas across a Ceph storage cluster. Cluster size needs to be flexible, and device failure is going to happen. CRUSH allows for the addition and removal of storage devices with as little movement of data as possible. Ceph utilizes the CRUSH algorithm to compute where data can be found or should be written. This eliminates metadata bottlenecks, which increases overall efficiency accessing data in the cluster. Ceph clients accessing storage and Ceph devices that replicate data to their peers both run the CRUSH algorithm. This allows the work to scale linearly with the size of the cluster.

CRUSH is an algorithm that can calculate the physical location of data in Ceph, given the object name, cluster map and CRUSH rules as input.

CRUSH distributes data evenly across available object storage devices in what is often described as a pseudo-random manner. Distribution is controlled by a hierarchical cluster map called a CRUSH map. The CRUSH map, which can be customized by the storage administrator, informs the cluster about the layout and capacity of nodes in the storage network and specifies how redundancy should be managed. 

CRUSH replicates data in multiple locations and fault domains. So when a disk fails, CRUSH replicates data across available OSDs. There is no need for RAID, which typically just adds to the hardware cost.

Ceph and CRUSH allow you to work in a heterogeneous structured environment that frees you from vendor lock-in and expensive proprietary hardware. CRUSH is also self-managing and self-healing, this reduces the overall need for human intervention in your data center.

CRUSH is one of the key features that makes Ceph powerful and uniquely scalable compared to other storage systems that we see today.

Ceph

Linux's impressive selection of file systems is Ceph, a distributed file system that incorporates replication and fault tolerance while maintaining POSIX compatibility.

CRUSH was designed for Ceph, an open source software designed to provide object-, block- and file-based storage under a unified system. Because CRUSH allows clients to communicate directly with storage devices without the need for a central index server to manage data object locations, Ceph clusters can store and retrieve data very quickly and scale up or down quite easily.

As if the dynamic and adaptive nature of the file system weren't enough, Ceph also implements some interesting features visible to the user. Users can create snapshots, for example, in Ceph on any subdirectory (including all of the contents). It's also possible to perform file and capacity accounting at the subdirectory level, which reports the storage size and number of files for a given subdirectory (and all of its nested contents).

Ceph is a distributed object store and file system designed to provide excellent performance, reliability and scalability.

Goals

• Easy scalability to multi-petabyte capacity (Required for BigData)

• High performance over varying workloads (input/output operations per second [IOPS] and bandwidth)

• Strong reliability

Note:

Ceph is not only a file system but an object storage ecosystem with enterprise-class features. Ceph isn't unique in the distributed file system space, but it is unique in the way that it manages a large storage ecosystem. Other examples of distributed file systems include the Google File System (GFS), the General Parallel File System (GPFS), and Lustre etc. The ideas behind Ceph appear to offer an interesting future for distributed file systems, as massive scales introduce unique challenges to the massive storage problem. 

Although Ceph is now integrated into the mainline Linux kernel, it's properly noted there as experimental. File systems in this state are useful to evaluate but are not yet ready for production environments.