Storage Provisioning and Networking - Deploying and Managing a Cloud Infrastructure - page 265

Options for secure data upload and download is provided. Encryption of data is also
provided as an additional option.

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S3 uses standard REST and SOAP interfaces to work with any web services develop-
ment toolkit.

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S3 is built for flexibility. Users can add protocol or functional layers. HTTP is offered
as the default download protocol. BitTorrent protocol interface is provided as an option
to lower costs and enable high-scale distribution.

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S3 also provides functionality to simplify management of data. For example, the
Amazon S3 Management Console ( http://console.aws.amazon.com/s3 ) provides
options for segregating data by buckets, monitoring and controlling spending, and
automatically archiving data to low-cost storage.

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Data Management
Amazon S3 offers data life cycle management, which refers to how the data is managed
from creation to deletion (if and when it is no longer needed). The life cycle management
handles storage capacity and automatic archival and sets up scheduled deletions.
One of the biggest advantages of S3 is the ability to dynamically increase or decrease
capacity as required. This eliminates the need for capacity planning in advance, especially
in circumstances where it is difficult to predetermine the quantity of data inflow. Moreover,
this mitigates underutilization of storage resources, thus also cutting operational costs.
Amazon S3 also takes care of automatic and transparent migration of data from old to
new hardware, thus eliminating the need to perform this tedious, risky, and costly process.
The S3 also provides programmatic options for setting up recurring deletions, includ-
ing high-volume deletions of objects in a single request. Objects can be standard, RSS, and
archived.

Data Durability and Reliability
To ensure durability, S3 redundantly stores data on multiple devices in multiple facilities.
For detecting corrupt data packets, S3 calculates checksums on all network traffic when
retrieving or storing data. To avoid tedious data verification and repair, S3 performs data
integrity tests regularly and automatically handles manual repairs if required.
Versioning systems are used to store, retrieve, and restore objects according to a saved
previous version. This way, unintended user actions and application failures can be con-
veniently reversed. The API provides the ability to retrieve an older version of an object
by specifying a version in the request. By default a request would retrieve the latest saved
version of the object.
Amazon claims that the S3 system is designed for 99.999999999 percent durability
and 99.99 percent availability of objects over a given year. Amazon further claims that
the system is able to sustain concurrent loss of data in two facilities.
Within Amazon S3, users get a couple of options for archival and low-cost storage. One
is a cheaper version of S3 offering lower redundancy, which is called Reduced Redundancy
Storage (RRS). The other is the Amazon Glacier, extremely low-cost storage for data