Cloud Computing Basics—Platform as a Service (PaaS)
Major PaaS Providers and Offerings in Cloud Services
PaaS services provide an opportunity to increase customers, boost revenue, add value to existing services and gain broader adoption of cloud services among business customers. Application development is a core capability, while additional capabilities often play to the cloud provider's brand building and strengths. To prepare for the PaaS, cloud providers are developing flexible cloud platforms to support a variety of functions for the cloud environment and processes. Examples of PaaS include, but are not limited to, Force.com, Microsoft Azure, Engine Yard, Heroku, CloudBees and Google App Engine.
Red Hat OpenShift
Red Hat OpenShift is a PaaS with Apache License 2.0. It has built-in support for Java, Python, PHP, Perl, Node.js, Ruby and extensible functionality to add languages. OpenShift supports MySQL, PostgreSQL and MongoDB. It supports Web-application frameworks, such as Rack for Ruby, WSGI for Python and PSGI for Perl. For Java, it covers end-to-end support for Java EE6, CDI/Weld, Spring, Liferay, Scala/Play!, JBoss AS7, JBoss EAP6, Tomcat 6 and 7 (JBoss EWS 1.0 and 2.0), Glassfish as DIY, Jetty as DIY, Eclipse, JBoss Tools, Jenkins, Cloud9 IDE, Appcelerator Titanium, Git, SSH access, Maven 3 and Ant. Three versions are available: OpenShift Online, OpenShift Enterprise and OpenShift Origin. A free tier is available for OpenShift Online with 512MB of RAM and 1GB disk. OpenShift Enterprise is a private cloud version from Red Hat.
CloudBees supports Java SE and Java EE. It also includes Tomcat, MySQL, commercial relational databases, BIG data—MongoDB and CouchDB in its stack. CloudBees brings quite a few unique features into the Java PaaS landscape, especially continuous integration—an entire development/testing/deployment management in the cloud. Application deployment requires no special framework, and it is easy to migrate applications in or out and to or from CloudBees. Developers can use the Jenkins service to have CloudBees automatically and continuously build, test, check in and check out code in the repository. CloudBees supports command-line tools, IDE tools (such as Eclipse), a Web-based console, Web access to logs, third-party developer/testing services and API access. New Relic monitoring is a part of the CloudBees ecosystem. Users can turn monitoring on for any of the applications with a few clicks. In CloudBees, the New Relic monitoring agent is deployed automatically into your application at the time of deployment. CloudBees also supports sending mail from applications with the SendGrid Service for RUN@cloud.
Google App Engine
Google App Engine (GAE) is designed to run Java, Python, Go or PHP applications on the Google infrastructure. In GAE, applications run within a secure environment with limited access to the underlying operating system; thus, existing applications may require significant changes—for example, applications can't write to the filesystem. It provides native support for Google Cloud SQL and Google Cloud Storage. It supports automatic scaling and load balancing. The Google App Engine SDK for Java, Python, PHP and Go are available. Users can use the Google plugin for Eclipse to develop and deploy applications. App Engine Datastore provides a NoSQL datastore, with a query engine and atomic transactions. Google Cloud SQL provides a relational database service based on the MySQL RDBMS, while Google Cloud Storage provides a storage service for objects and files. For free usage, applications can use up to 1GB of storage and adequate CPU and bandwidth to support a capable application, which can serve around 5 million requests a month. It also provides simulation of Google App Engine on your computer.
Cloud Foundry is an open-source PaaS developed by VMware and released under the Apache License 2.0. It is written in Ruby. Cloud Foundry supports the Java, Ruby, Node.js and Scala languages with runtime environments Java 6, Java 7, Ruby 1.8, Ruby 1.9, Node.js, Spring Framework 3.1, Rails and Sinatra. Cloud Foundry supports the MySQL and vFabric Postgres relational databases and the MongoDB document-based database. Users can use RabbitMQ, a reliable, scalable and portable messaging system for applications. Micro Cloud Foundry is a downloadable version of Cloud Foundry that can run on a developer's machine.
Heroku is a polyglot cloud application platform that supports Clojure, Facebook, Java, Spring, Play, Node.js, Python, Django, Ruby on Rails and Scala. It supports PostgreSQL and MongoDB as SQL and NoSQL databases, respectively. Heroku aggregates three categories of logs: app logs, system logs and API logs. It is available in the US and EU. Users can use the maintenance mode to disable access to their applications for some duration of time, where it will serve a static page to all users. Users can enable SSL to ensure that all information is transmitted securely. Its production check feature is useful to verify application configuration against recommended criteria to ensure maximum uptime.
Windows Azure is a PaaS offering from Microsoft. Microsoft released it in February 2010. Application developers can write code for it in different programming languages; there are definite SDKs started by Microsoft for Java, Python, Node.js and .NET. Microsoft publishes the source code for the client libraries on GitHub. For data storage, SQL Azure is a cloud-based scalable and highly available database service built on SQL server. Windows Azure Blobs provide storage for unstructured binary data. AppFabric simplifies connecting to cloud services and on-premise applications. For queued messaging, queues and service bus features are available. With the use of the caching and content delivery network, application performance can be enhanced. Broadcasters successfully used Windows Azure Media Services to stream the London 2012 Olympics. Windows Azure Active Directory manages user information similar to Windows Server Active Directory.
Amazon Elastic Beanstalk
Elastic Beanstalk is a PaaS offering from AWS to deploy and manage applications quickly in the AWS cloud. Elastic Beanstalk manages auto-scaling, load balancing and application monitoring. AWS Elastic Beanstalk supports Java, PHP, Python, Node.js, Ruby and .NET Web applications with the Apache Tomcat, Apache HTTP Server, Nginx, Passenger and Microsoft IIS 7.5 development stacks, respectively. It runs on the Amazon Linux AMI, Windows Server 2008 R2 AMI and the Windows Server 2012 AMI. Consumers can create 25 applications and 500 application versions. The application size can be up to 512MB. Users can use Eclipse and Visual Studio to deploy applications to AWS Elastic Beanstalk. Users can leverage the AWS Toolkit for Eclipse and the AWS Toolkit for Visual Studio for Java applications and .NET applications, respectively. Application files and optionally server log files are stored in Amazon S3. Amazon RDS, DynamoDB and SimpleDB can be used as a datastore, or users can use Oracle, Microsoft SQL Server or any other relational databases running on Amazon EC2.
Mitesh Soni has been associated with the Cloud Services Team for the past three years, which is a part of the Research and Innovation Group of iGATE. Currently, he is working there in the capacity as Technical Lead. He loves to write on technical and soci
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