Big data is big in size. Exactly how much data can be
classified as big data is not very clear cut, so let's not get bogged down in
that debate. For a small company that is used to dealing with data in
gigabytes, 10 TB of data would be BIG. However for companies like Facebook and
Yahoo, petabytes is big.
Just the size of big data, makes it impossible (or at least
cost prohibitive) to store it in traditional storage like databases or
conventional filers. We are talking about cost to store gigabytes of data.
Using traditional storage filers can cost a lot of money to store big data.
Big Data Is
Unstructured or Semi-Structured
A lot of big data is unstructured. For example, click stream
log data might look like:
time stamp, user_id,
page, referrer_page
Lack of structure makes relational databases not well suited
to store big data. Plus, not many databases can cope with storing billions of
rows of data.
How Hadoop Solves the
Big Data Problem
Hadoop is built to run on a cluster of machines.
Let’s start with an example. Let's say that we need to store
lots of photos. We will start with a single disk. When we exceed a single disk,
we may use a few disks stacked on a machine. When we max out all the disks on a
single machine, we need to get a bunch of machines, each with a bunch of disks.
This is exactly how Hadoop is built. Hadoop is designed to
run on a cluster of machines from the get go.
Hadoop clusters scale horizontally
More storage and compute power can be achieved by adding
more nodes to a Hadoop cluster. This eliminates the need to buy more and more
powerful and expensive hardware.
Hadoop can handle
unstructured/semi-structured data
Hadoop doesn't enforce a schema on the data it stores. It
can handle arbitrary text and binary data. So Hadoop can digest any
unstructured data easily.
Hadoop clusters
provides storage and computing
We saw how having separate storage and processing clusters
is not the best fit for big data. Hadoop clusters, however, provide storage and
distributed computing all in one.
The Business Case for Hadoop
Hadoop provides
storage for big data at reasonable cost
Storing big data using traditional storage can be expensive.
Hadoop is built around commodity hardware, so it can provide fairly large
storage for a reasonable cost. Hadoop has been used in the field at petabyte
scale.
One study by Cloudera suggested that enterprises usually
spend around $25,000 to $50,000 per terabyte per year. With Hadoop, this cost
drops to a few thousand dollars per terabyte per year. As hardware gets cheaper
and cheaper, this cost continues to drop.
Hadoop allows for the
capture of new or more data
Sometimes organizations don't capture a type of data because
it was too cost prohibitive to store it. Since Hadoop provides storage at
reasonable cost, this type of data can be captured and stored.
One example would be website click logs. Because the volume
of these logs can be very high, not many organizations captured these. Now with
Hadoop it is possible to capture and store the logs.
With Hadoop, you can
store data longer
To manage the volume of data stored, companies periodically
purge older data. For example, only logs for the last three months could be
stored, while older logs were deleted. With Hadoop it is possible to store the
historical data longer. This allows new analytics to be done on older
historical data.
For example, take click logs from a website. A few years
ago, these logs were stored for a brief period of time to calculate statistics
like popular pages. Now with Hadoop, it is viable to store these click logs for
longer period of time.
Hadoop provides
scalable analytics
There is no point in storing all this data if we can't
analyze them. Hadoop not only provides distributed storage, but also
distributed processing as well, which means we can crunch a large volume of
data in parallel. The compute framework of Hadoop is called Map Reduce.
MapReduce has been proven to the scale of petabytes.
Hadoop provides rich
analytics
Native Map Reduce supports Java as a primary programming
language. Other languages like Ruby, Python and R can be used as well.
Of course, writing custom MapReduce code is not the only way
to analyze data in Hadoop. Higher-level Map Reduce is available. For example, a
tool named Pig takes English like data flow language and translates them into
MapReduce. Another tool, Hive, takes SQL queries and runs them using MapReduce.
Business intelligence (BI) tools can provide even higher level of analysis.
There are tools for this type of analysis as well.
QUANTUM Global Academy
is famous for providing training in Hadoop and Big Data, PMP, Six
Sigma, ITIL, event management, retail management and logistics & supply
chain in Gurgaon, Delhi. We are here to help for improving company’s
performance and productivity. For more information visit our website www.quantumglobal.org/
or can call us at 01244609530


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