Testing and Deployment: Quality Is King - Deploying and Managing a Cloud Infrastructure - page 297

EC2 offers massive scalability and performance, making it ideal for large enterprise
applications that need to support millions of customer queries.
Amazon provides multiple offerings, including Elastic Block Store (EBS), Simple Storage
Service (S3), and Relational Database Service (RDS). (We covered EBS and S3 in Chapter 9,
“Storage Provisioning and Networking.”) RDS offers SQL Server, MySQL, and Oracle
storage instances. Apart from providing a list of available relational storage solutions, the
two biggest advantages of RDS include availability and database size (200 to 1,000 GBs).
When the customer creates a database instance, the Amazon RDS creates a standby replica
in another Availability Zone that supports synchronous replication.
This means that the availability of the application that uses the RDS service underneath
can continue to operate unless there is a service blackout in two different Availability Zones
containing the same replica. However, the only major problem with such a feature is that
organizations carrying and processing private customer data and bound by regional laws to
not export the data to other countries or regions will have to find another solution or deploy
their own.
Other Features
Amazon provides other rich features as well, such as the availability of a more costly data-
base solution that utilizes SSD drives to deliver up to 30,000 I/O operations per second.
A maximum of five replicas are supported. Backups are more frequent than they are in
Windows Azure and provide snapshots down to the second. Apart from providing standby
replicas that support synchronous replication, the RDS comes with the ability to automati-
cally replace dead hosts.
Rackspace
Rackspace is powered by OpenStack, which offers an open and flexible cloud
platform. Rackspace provides a responsive API and a good dashboard panel to manage
server instances. The OpenStack API used by the next-generation Rackspace cloud service
includes new features such as management of server metadata.
Just as with Amazon, the Rackspace customers can choose a region to host their data
and services. Regional control also helps in managing availability and connectivity to cloud
services. Data replicas are spread across regions to aid with disaster recovery in case of a
regional failure.
Rackspace uses OpenStack Swift. Swift is a distributed object storage system for static
data objects such as VM snapshots and backup. In design and principle, Swift resembles
Amazon's S3 storage technology. Objects are written to multiple drives across the data
center. Swift takes care of data replication and integrity across the cluster. In the case of
a drive failure, Swift is responsible for replicating data to a healthy drive. This powerful
feature is called self-healing .
Swift allows objects of 5 GB in size. By design, a proxy handles all the requests and
looks up the location of the account, container and object. It then routes the request
accordingly. The proxy is also responsible for handling failures.