Code Library

The data storage options listed earlier include both Platform-as-a-Service (PaaS) and Infrastructure-as-a-Service (IaaS) solutions.

In a PaaS solution, Microsoft manages the hardware and software infrastructure and you just use the service. SQL Database is a PaaS feature of Azure. You ask for databases, and behind the scenes Azure sets up and configures the virtual machines (VMs) and sets up the databases on them. You don’t have direct access to the VMs and don’t have to manage them.

In an IaaS solution, you set up, configure, and manage VMs that run in Microsoft’s data center infrastructure, and you put whatever you want on them. Microsoft provides a gallery of preconfigured VM images for common VM configurations. For example, you can install preconfigured VM images for Windows Server 2008, Windows Server 2012, BizTalk Server, Oracle WebLogic Server, Oracle Database, and others.

PaaS data solutions that Azure offers include:
• Azure SQL Database (formerly known as SQL Azure) A cloud relational database based on SQL Server.
• Azure Table storage A column-oriented NoSQL database.
• Azure Blob storage File storage in the cloud.

For IaaS, you can run any software that you can load onto a VM, for example:
• Relational databases such as SQL Server, Oracle, MySQL, SQL Compact, SQLite, or Postgres.
• Key/value data stores such as Memcached, Redis, Cassandra, and Riak.
• Column data stores such as HBase.
• Document databases such as MongoDB, RavenDB, and CouchDB.
• Graph databases such as Neo4j.

The IaaS option gives you almost unlimited data storage options, and many of them are especially easy to use because you can create VMs using preconfigured images. For example, in the management portal, go to Virtual Machines, click the Images tab, and then click Browse VM Depot.

You then see a list of hundreds of preconfigured VM images, and you can create a VM from an image that has a database management system such as MongoDB, Neo4J, Redis, Cassandra, or CouchDB preinstalled:

Azure makes IaaS data storage options as easy to use as possible, but the PaaS offerings have many advantages that make them more cost-effective and practical for many scenarios:

• You don’t have to create VMs; you just use the portal or a script to set up a data store. If you want a 200-terabyte data store, you just click a button or run a command, and in seconds it’s ready for you to use.

• You don’t have to manage or patch the VMs used by the service; Microsoft does that for you automatically.

• You don’t have to worry about setting up infrastructure for scaling or high availability; Microsoft handles all that for you.

• You don’t have to buy licenses; license fees are included in the service fees.

• You pay only for what you use.

PaaS data storage options in Azure include offerings by third-party providers. For example, you can choose the MongoLab Add-On from the Azure Store to provision a MongoDB database as a service.

Source of Information : Building Cloud Apps With Microsoft Azure