eclipse_newsletter/2014/june/content/en_article3.php - gerrit/www.eclipse.org/community - Git at Google

 <?php
 /*******************************************************************************
  * Copyright (c) 2015 Eclipse Foundation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *    Eric Poirier (Eclipse Foundation) - Initial implementation
  *******************************************************************************/
 ?>

 <h1 class="article-title"><?php echo $pageTitle; ?></h1>
   <p>
     <a
       href="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud.png"><img
       class="size-full wp-image-1134 alignleft"
       style="margin-left: 15px; margin-right: 15px;" alt="scout_cloud"
       src="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud.png"
       width="336" height="164" /></a>
   </p>
   <p>This article describes the initial cloud support that was added to
     Eclipse Scout with the Luna release. In the text below, we first
     motivate our efforts in this area and describe the approach chosen
     for the Scout framework. Then, the abstraction layer to implement
     access to distributed caching and messaging is discussed. And
     finally, we list the necessary requirements for Platform as a
     Service (PaaS) offerings and provide an overview of suitable public
     PaaS provider.</p>
   <br>
   <h2>
     <strong>Motivation<br />
     </strong>
   </h2>
   <p>Since 2006, when Amazon started its Web Services (AWS) offering,
     the cloud market has become a growing multi billion dollar market.
     Following customer demand, many software vendors start to provide
     their products on a Software as a Service (SaaS) basis. For
     organisations developing in-house applications, the usage of
     Platform as a Service (PaaS) offerings can help to significantly
     reduce time and costs to develop, deploy and operate applications.
     This is especially true for startup organisations, that need to
     focus their efforts on their product and the time to market for new
     features and critical bug fixes. In addition, many PaaS offerings
     support dynamic scaling by adding additional server nodes when the
     load on the existing infrastructure increases.</p>
   <p>We are convinced that the trend to move applications to the cloud
     has only begun, and will grow even stronger in the future. With the
     Luna release we targeted public PaaS providers for Scout&#8217;s
     initial cloud support. This should minimize developers efforts to
     build scalable Scout applications and to actually run such
     application in the cloud. And because we know that you won&#8217;t
     be happy to rewrite your application when you need (or want) to
     change your PaaS provider in the future, Scout&#8217;s cloud support
     works as independent of any specific PaaS as possible. Exactly
     according to the spirit of Scout&#8217;s long term strategy.</p>
   <p>&nbsp;</p>
   <h2>How to scale Scout Applications</h2>
   <p>The classical way to scale web applications is to add/remove
     application server nodes depending on the actual load on the current
     nodes. Communication between the application&#8217;s clients to the
     server are running over a common load balancer that is distributing
     the requests from clients to the available server nodes. And the
     server nodes are accessing a common database infrastructure to store
     and retrieve data that is relevant to the specific application.</p>
   <p>This is exactly the scenario that is supported by the initial Scout
     cloud support shipped with the Luna release train. As shown in the
     figure below, a Scout application may now work with a dynamic number
     of application servers operating behind a common load balancer. The
     load balancer then distributes incoming client requests to the next
     available application server. The individual servers then use a
     common infrastructure to access a distributed cache, the message
     queue and the data base.</p>
   <p>
     <a
       href="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud_architecture.png"><img
       class="alignnone  wp-image-1126" alt="scout_cloud_architecture"
       src="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud_architecture.png"
       width="731" height="423" /></a>
   </p>
   <p>
     <span id="more-1124"></span>
   </p>
   <p>
     In the past, a Scout server created a <em>ServerSession</em> for
     each individual client. This server session was then used to
     identify the Scout client and to store client specific data.
     Unfortunately, the new application architecture no longer guarantees
     that subsequent requests of a specific client are handled by the
     same Scout server instance. To ensure that each client request can
     be processed correctly the server sessions are now held in a
     distributed cache that is accessed through a caching service. This
     caching service is one of the newly added components to the Scout
     framework.
   </p>
   <p>An additional change was necessary to properly handle client
     notification in scalable Scout applications. Client notifications
     are used in the Scout framework to push messages from the Scout
     server to the Scout clients. To manage the client notification
     messages, a queue is used to hold the messages that need to be
     delivered. With the scalable server architecture coming with the
     Luna release, Scout server applications hold individual queues that
     are updated from a common message queue using the Pub/Sub pattern.
     When a specific Scout server adds a client notification to the
     queue, or sends a notification to a specified client, the
     information is now distributed among all server instances using the
     newly added message queue.</p>
   <p>&nbsp;</p>
   <h2>PaaS Independence</h2>
   <p>To allow for long term planning, Scout applications should be as
     independent of individual PaaS providers as possible. Therefore, the
     Scout framework must not directly depend on the availability of
     specific distributed caching or message queues technologies. Rather,
     as shown in the diagram below, it takes advantage of its service
     oriented architecture. In the Scout runtime server bundle the
     necessary services to access caching and the message queue are
     located using the OSGi service registry.</p>
   <p>
     <a
       href="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_server_with_cache_and_messaging.png"><img
       class="alignnone  wp-image-1127"
       alt="scout_server_with_cache_and_messaging"
       src="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_server_with_cache_and_messaging.png"
       width="760" height="361" /></a>
   </p>
   <p>&nbsp;</p>
   <p>
     By providing alternative implementations to specific caching and
     message queue technologies, the exact same server code can be used
     for different PaaS environments. To build Scout applications for a
     specific PaaS provider, the developer only needs to select matching
     service plugins and add these to the the server product. Scout
     caching support is already available on the <a
       href="https://marketplace.eclipse.org/content/cloud-support-eclipse-scout"
       target="_blank">Eclipse marketplace</a> for <a
       href="http://memcached.org/" target="_blank">memcached</a> and <a
       href="http://redis.io/" target="_blank">redis</a>. In the case of
     message queues, support is available for <a
       href="http://activemq.apache.org/" target="_blank">ActiveMQ</a>
     and <a href="http://www.rabbitmq.com/" target="_blank">RabbitMQ</a>
     . Together with the previously existing support for <a
       href="http://www.mysql.com/" target="_blank">MySQL</a> and <a
       href="http://www.postgresql.org/" target="_blank">PostgreSQL</a>
     Scout allows to implement web application that run in many different
     environments.
   </p>
   <h2>Suitable PaaS Providers</h2>
   <p>Currently, most PaaS providers agree on a number of important core
     aspects such as support for Java 1.7, or providing Tomcat
     application servers. To quickly get started with Scout cloud
     application development, we tried to compile a short list of public
     PaaS providers that also offer application hosting. And for some of
     them, we did actual trials to verify, that the cloud support with
     the Scout Luna release actually works as expected.</p>
   <p>Prior to the selection process for the short list, some hard and
     soft requirements where compiled. The goal of the list of
     requirements is to find PaaS providers that seem suitable to host
     realistically complex Scout applications including dynamic scaling
     of server nodes, and access to shared databases, message queues and
     caching. At the same time, these services should be based on open
     standards to allow for a painless migration of the application to a
     different PaaS provider.</p>
   <p>The hard requirements also include full Java 1.7 support, a servlet
     container and access to a relational database, as well as messaging
     and caching. Once these requirements are met, dynamic scaling and
     the support of open standards for databases, caching and messaging
     have been added as soft requirements.</p>
   <p>
     <strong>Hard Requirements</strong>
   </p>
   <ul>
     <li>Public PaaS with Hosting</li>
     <li>Java 1.7</li>
     <li>Servlet Container</li>
     <li>Relational Database</li>
     <li>Message Service</li>
     <li>Cache Service</li>
   </ul>
   <p>
     <strong>Soft Requirements</strong>
   </p>
   <ul>
     <li>Automatic Scaling</li>
     <li>Open Source Database</li>
     <li>Open Source Caching</li>
     <li>Open Source Messaging</li>
   </ul>
   <p>
     The overview provided below presents the short list of public PaaS
     provider. To create this shortlist, we started with the offerings
     listed of <a href="http://www.linkedin.com/in/thecloud">Khazret
       Sapenov&#8217;s</a> <a
       href="https://docs.google.com/spreadsheet/ccc?key=0AiIXCd1D_TmGdFluZEJQakV5M0QwWXNWaXREcWR0Q0E"
       target="_blank">PaaS list</a>. The hard requirements to offer Java
     support reduced the list to roughly 35 entries. Requiring public
     hosting and eliminating double entries, offerings no longer
     available reduced the list to 14 elements. The HANA Cloud Platform,
     Uhuru PaaS and the WSO2 Stratos Live were also removed from the list
     as its offerings primarily focus on supporting proprietary software
     of the vendor itself. This process resulted in the list of the 11
     &#8220;surviving&#8221; PaaS offerings.
   </p>
   <table>
     <tbody>
       <tr>
         <th>Provider</th>
         <th>Product</th>
         <th>Hard Requirements</th>
         <th>Autoscaling</th>
         <th>Other Soft Requirements</th>
       </tr>
       <tr>
         <td>Amazon</td>
         <td><a href="http://aws.amazon.com/elasticbeanstalk/"
           target="_blank">Elastic Beanstalk</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">MySQL, Memacached,
           RabbitMQ</td>
       </tr>
       <tr>
         <td>CentruyLink</td>
         <td><a href="https://www.appfog.com/" target="_blank">AppFog</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: #ffaaaa;">NOK</td>
         <td style="background-color: lightgreen;">MySQL, Redis, RabbitMQ</td>
       </tr>
       <tr>
         <td>Clever Cloud</td>
         <td><a href="https://www.clever-cloud.com/en/" target="_blank">Clever
             Cloud</a></td>
         <td style="background-color: #ffaaaa;">NOK: Message and cache
           services missing</td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">MySQL</td>
       </tr>
       <tr>
         <td>CloudBees</td>
         <td><a href="http://www.cloudbees.com/run" target="_blank">Run@Cloud</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">MySQL, Memacached,
           RabbitMQ</td>
       </tr>
       <tr>
         <td>Google</td>
         <td><a href="https://cloud.google.com/products/app-engine/"
           target="_blank">AppEngine</a></td>
         <td style="background-color: #ffaaaa;">Java Sandbox only,
           Message service missing</td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">MySQL, Memcached</td>
       </tr>
       <tr>
         <td>Hivext</td>
         <td><a href="http://jelastic.com/" target="_blank">Jelastic</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">MySQL, Memcached, JMS</td>
       </tr>
       <tr>
         <td>Microsoft</td>
         <td><a href="http://azure.microsoft.com/en-us/" target="_blank">Microsoft
             Azure</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: #ffaaaa;">Azure SQL Database, Azure
           Cache, Azure Service Bus</td>
       </tr>
       <tr>
         <td>Oracle</td>
         <td><a href="https://cloud.oracle.com/java" target="_blank">Cloud
             Java</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: #ffaaaa;">NOK</td>
         <td style="background-color: #ffaaaa;">Oracle Database Cloud
           Service, Coherence, Oracle Messaging Cloud Service</td>
       </tr>
       <tr>
         <td>Pivotal</td>
         <td><a href="https://www.gopivotal.com/about" target="_blank">Pivotal
             One</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: #ffaaaa;">NOK</td>
         <td style="background-color: lightgreen;">MySQL, Memcached,
           RabbitMQ</td>
       </tr>
       <tr>
         <td>Red Hat</td>
         <td><a href="https://www.openshift.com/" target="_blank">OpenShift</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: lightgreen;">MySQL, Redis, ActiveMQ</td>
       </tr>
       <tr>
         <td>Salesforce</td>
         <td><a href="https://www.heroku.com/" target="_blank">Heroku</a></td>
         <td style="background-color: lightgreen;">OK</td>
         <td style="background-color: #ffaaaa;">NOK</td>
         <td style="background-color: lightgreen;">PostgreSQL, Memcached,
           RabbitMQ</td>
       </tr>
     </tbody>
   </table>
   <br>
   <p>
     Please note that the above list is bound to be out of date almost
     immediately. Some of the offerings have been around for a while, but
     the dynamics in the PaaS space is very high. Just to name an
     example, we should have included the Stratos PaaS, as this offering
     has been donated to Apache last year and been promoted to an Apache
     top level project <a
       href="https://twitter.com/TheASF/status/473781285169938432"
       target="_blank">recently</a>.
   </p>
   <h2>Conclusions and Outlook</h2>
   <p>With the Eclipse Luna relase, Scout adds initial cloud support for
     building enterprise applications. This support makes writing
     scalable business applications as simple as possible. And with
     Scout&#8217;s abstraction layer for databases, caching and
     messaging, Scout applications become de-facto independent of
     specific PaaS provider. This let&#8217;s you focus on implementing
     functionality and removes the worry of selecting the
     &#8220;right&#8221; PaaS provider.</p>
   <p>When working with Scout desktop clients, complete scaling is
     already supported with the Scout Luna release. A logical next step
     is to add support for scaling the web servers. As the Scout web
     servers are running the web-clients of Scout web applications, this
     addition will then allow to scale complete Scout web applications.</p>
   <h2>Further Reading</h2>
   <ul>
     <li><a href="https://www.eclipsecon.org/na2014/session/scout-cloud"
       target="_blank">Scout in the Cloud</a> session at EclipseCon, San
       Francisco, 2014</li>
     <li><a
       href="http://searchcloudapplications.techtarget.com/news/2240216336/Eclipse-Scout-Open-source-framework-offers-enterprise-cloud-support"
       target="_blank">Techtarget interview</a> by <i>Caroline de
         Lacvivier</i>, 18 Mar 2014</li>
     <li><a href="https://wiki.eclipse.org/Scout/Tutorial/4.0/Cloud"
       target="_blank">Wiki Tutorial</a> to add Scout cloud support (work
       in progress)</li>
     <li>Other: <a href="http://eclipse.org/scout/">Project Home</a>, <a
       href="http://www.eclipse.org/forums/index.php?t=thread&amp;frm_id=174">Forum</a>,
       <a href="http://wiki.eclipse.org/Scout">Wiki</a>, <a
       href="https://twitter.com/#!/EclipseScout">Twitter</a></li>
   </ul>
   <h2>
     <i>Acknowlegements</i>
   </h2>
   <p>
     <i>This article is based on the master thesis of Thomas Schweigler,
       that has been also supervised by Scout committer Judith Gull. We
       expect to be able to provide access to the full thesis (in German)
       in the near future. </i><i>The cloud icon used at the beginning is
       available at <a href="http://www.iconarchive.com/">www.iconarchive.com</a>.
       According to its <a
       href="http://www.iconarchive.com/show/ios7-style-metro-ui-icons-by-igh0zt/MetroUI-Apps-iCloud-icon.html">terms</a>,
       the icon can be used freely for non-commercial use.
     </i>
   </p>

 <div class="bottomitem">
   <h3>About the Authors</h3>

   <div class="row">
     <div class="col-sm-12">
       <div class="row">
         <div class="col-sm-8">
           <img class="author-picture"
         src="/community/eclipse_newsletter/2014/june/images/mzi3.png"
         width="75" alt="Matthias Zimmermann" />
         </div>
         <div class="col-sm-16">
           <p class="author-name">
         Matthias Zimmermann<br />
         <a target="_blank" href="http://www.bsiag.com/">BSI</a>
       </p>
       <ul class="author-link">
         <li><a target="_blank" href="http://www.bsiag.com/scout/">Blog</a></li>
         <li><a target="_blank" href="https://twitter.com/EclipseScout">Twitter</a></li>
         <!--<li><a target="_blank" href="">Google +</a></li>-->
       </ul>
         </div>
       </div>
     </div>
   </div>
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	<?php
	/*******************************************************************************
	* Copyright (c) 2015 Eclipse Foundation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Eric Poirier (Eclipse Foundation) - Initial implementation
	*******************************************************************************/
	?>

	<h1 class="article-title"><?php echo $pageTitle; ?></h1>
	<p>
	<a
	href="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud.png"><img
	class="size-full wp-image-1134 alignleft"
	style="margin-left: 15px; margin-right: 15px;" alt="scout_cloud"
	src="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud.png"
	width="336" height="164" /></a>
	</p>
	<p>This article describes the initial cloud support that was added to
	Eclipse Scout with the Luna release. In the text below, we first
	motivate our efforts in this area and describe the approach chosen
	for the Scout framework. Then, the abstraction layer to implement
	access to distributed caching and messaging is discussed. And
	finally, we list the necessary requirements for Platform as a
	Service (PaaS) offerings and provide an overview of suitable public
	PaaS provider.</p>
	<br>
	<h2>
	<strong>Motivation<br />
	</strong>
	</h2>
	<p>Since 2006, when Amazon started its Web Services (AWS) offering,
	the cloud market has become a growing multi billion dollar market.
	Following customer demand, many software vendors start to provide
	their products on a Software as a Service (SaaS) basis. For
	organisations developing in-house applications, the usage of
	Platform as a Service (PaaS) offerings can help to significantly
	reduce time and costs to develop, deploy and operate applications.
	This is especially true for startup organisations, that need to
	focus their efforts on their product and the time to market for new
	features and critical bug fixes. In addition, many PaaS offerings
	support dynamic scaling by adding additional server nodes when the
	load on the existing infrastructure increases.</p>
	<p>We are convinced that the trend to move applications to the cloud
	has only begun, and will grow even stronger in the future. With the
	Luna release we targeted public PaaS providers for Scout’s
	initial cloud support. This should minimize developers efforts to
	build scalable Scout applications and to actually run such
	application in the cloud. And because we know that you won’t
	be happy to rewrite your application when you need (or want) to
	change your PaaS provider in the future, Scout’s cloud support
	works as independent of any specific PaaS as possible. Exactly
	according to the spirit of Scout’s long term strategy.</p>
	<p> </p>
	<h2>How to scale Scout Applications</h2>
	<p>The classical way to scale web applications is to add/remove
	application server nodes depending on the actual load on the current
	nodes. Communication between the application’s clients to the
	server are running over a common load balancer that is distributing
	the requests from clients to the available server nodes. And the
	server nodes are accessing a common database infrastructure to store
	and retrieve data that is relevant to the specific application.</p>
	<p>This is exactly the scenario that is supported by the initial Scout
	cloud support shipped with the Luna release train. As shown in the
	figure below, a Scout application may now work with a dynamic number
	of application servers operating behind a common load balancer. The
	load balancer then distributes incoming client requests to the next
	available application server. The individual servers then use a
	common infrastructure to access a distributed cache, the message
	queue and the data base.</p>
	<p>
	<a
	href="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud_architecture.png"><img
	class="alignnone wp-image-1126" alt="scout_cloud_architecture"
	src="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_cloud_architecture.png"
	width="731" height="423" /></a>
	</p>
	<p>
	<span id="more-1124"></span>
	</p>
	<p>
	In the past, a Scout server created a <em>ServerSession</em> for
	each individual client. This server session was then used to
	identify the Scout client and to store client specific data.
	Unfortunately, the new application architecture no longer guarantees
	that subsequent requests of a specific client are handled by the
	same Scout server instance. To ensure that each client request can
	be processed correctly the server sessions are now held in a
	distributed cache that is accessed through a caching service. This
	caching service is one of the newly added components to the Scout
	framework.
	</p>
	<p>An additional change was necessary to properly handle client
	notification in scalable Scout applications. Client notifications
	are used in the Scout framework to push messages from the Scout
	server to the Scout clients. To manage the client notification
	messages, a queue is used to hold the messages that need to be
	delivered. With the scalable server architecture coming with the
	Luna release, Scout server applications hold individual queues that
	are updated from a common message queue using the Pub/Sub pattern.
	When a specific Scout server adds a client notification to the
	queue, or sends a notification to a specified client, the
	information is now distributed among all server instances using the
	newly added message queue.</p>
	<p> </p>
	<h2>PaaS Independence</h2>
	<p>To allow for long term planning, Scout applications should be as
	independent of individual PaaS providers as possible. Therefore, the
	Scout framework must not directly depend on the availability of
	specific distributed caching or message queues technologies. Rather,
	as shown in the diagram below, it takes advantage of its service
	oriented architecture. In the Scout runtime server bundle the
	necessary services to access caching and the message queue are
	located using the OSGi service registry.</p>
	<p>
	<a
	href="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_server_with_cache_and_messaging.png"><img
	class="alignnone wp-image-1127"
	alt="scout_server_with_cache_and_messaging"
	src="http://www.bsiag.com/scout/wp-content/uploads/2014/06/scout_server_with_cache_and_messaging.png"
	width="760" height="361" /></a>
	</p>
	<p> </p>
	<p>
	By providing alternative implementations to specific caching and
	message queue technologies, the exact same server code can be used
	for different PaaS environments. To build Scout applications for a
	specific PaaS provider, the developer only needs to select matching
	service plugins and add these to the the server product. Scout
	caching support is already available on the <a
	href="https://marketplace.eclipse.org/content/cloud-support-eclipse-scout"
	target="_blank">Eclipse marketplace</a> for <a
	href="http://memcached.org/" target="_blank">memcached</a> and <a
	href="http://redis.io/" target="_blank">redis</a>. In the case of
	message queues, support is available for <a
	href="http://activemq.apache.org/" target="_blank">ActiveMQ</a>
	and <a href="http://www.rabbitmq.com/" target="_blank">RabbitMQ</a>
	. Together with the previously existing support for <a
	href="http://www.mysql.com/" target="_blank">MySQL</a> and <a
	href="http://www.postgresql.org/" target="_blank">PostgreSQL</a>
	Scout allows to implement web application that run in many different
	environments.
	</p>
	<h2>Suitable PaaS Providers</h2>
	<p>Currently, most PaaS providers agree on a number of important core
	aspects such as support for Java 1.7, or providing Tomcat
	application servers. To quickly get started with Scout cloud
	application development, we tried to compile a short list of public
	PaaS providers that also offer application hosting. And for some of
	them, we did actual trials to verify, that the cloud support with
	the Scout Luna release actually works as expected.</p>
	<p>Prior to the selection process for the short list, some hard and
	soft requirements where compiled. The goal of the list of
	requirements is to find PaaS providers that seem suitable to host
	realistically complex Scout applications including dynamic scaling
	of server nodes, and access to shared databases, message queues and
	caching. At the same time, these services should be based on open
	standards to allow for a painless migration of the application to a
	different PaaS provider.</p>
	<p>The hard requirements also include full Java 1.7 support, a servlet
	container and access to a relational database, as well as messaging
	and caching. Once these requirements are met, dynamic scaling and
	the support of open standards for databases, caching and messaging
	have been added as soft requirements.</p>
	<p>
	<strong>Hard Requirements</strong>
	</p>
	<ul>
	<li>Public PaaS with Hosting</li>
	<li>Java 1.7</li>
	<li>Servlet Container</li>
	<li>Relational Database</li>
	<li>Message Service</li>
	<li>Cache Service</li>
	</ul>
	<p>
	<strong>Soft Requirements</strong>
	</p>
	<ul>
	<li>Automatic Scaling</li>
	<li>Open Source Database</li>
	<li>Open Source Caching</li>
	<li>Open Source Messaging</li>
	</ul>
	<p>
	The overview provided below presents the short list of public PaaS
	provider. To create this shortlist, we started with the offerings
	listed of <a href="http://www.linkedin.com/in/thecloud">Khazret
	Sapenov’s</a> <a
	href="https://docs.google.com/spreadsheet/ccc?key=0AiIXCd1D_TmGdFluZEJQakV5M0QwWXNWaXREcWR0Q0E"
	target="_blank">PaaS list</a>. The hard requirements to offer Java
	support reduced the list to roughly 35 entries. Requiring public
	hosting and eliminating double entries, offerings no longer
	available reduced the list to 14 elements. The HANA Cloud Platform,
	Uhuru PaaS and the WSO2 Stratos Live were also removed from the list
	as its offerings primarily focus on supporting proprietary software
	of the vendor itself. This process resulted in the list of the 11
	“surviving” PaaS offerings.
	</p>
	<table>
	<tbody>
	<tr>
	<th>Provider</th>
	<th>Product</th>
	<th>Hard Requirements</th>
	<th>Autoscaling</th>
	<th>Other Soft Requirements</th>
	</tr>
	<tr>
	<td>Amazon</td>
	<td><a href="http://aws.amazon.com/elasticbeanstalk/"
	target="_blank">Elastic Beanstalk</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">MySQL, Memacached,
	RabbitMQ</td>
	</tr>
	<tr>
	<td>CentruyLink</td>
	<td><a href="https://www.appfog.com/" target="_blank">AppFog</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: #ffaaaa;">NOK</td>
	<td style="background-color: lightgreen;">MySQL, Redis, RabbitMQ</td>
	</tr>
	<tr>
	<td>Clever Cloud</td>
	<td><a href="https://www.clever-cloud.com/en/" target="_blank">Clever
	Cloud</a></td>
	<td style="background-color: #ffaaaa;">NOK: Message and cache
	services missing</td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">MySQL</td>
	</tr>
	<tr>
	<td>CloudBees</td>
	<td><a href="http://www.cloudbees.com/run" target="_blank">Run@Cloud</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">MySQL, Memacached,
	RabbitMQ</td>
	</tr>
	<tr>
	<td>Google</td>
	<td><a href="https://cloud.google.com/products/app-engine/"
	target="_blank">AppEngine</a></td>
	<td style="background-color: #ffaaaa;">Java Sandbox only,
	Message service missing</td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">MySQL, Memcached</td>
	</tr>
	<tr>
	<td>Hivext</td>
	<td><a href="http://jelastic.com/" target="_blank">Jelastic</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">MySQL, Memcached, JMS</td>
	</tr>
	<tr>
	<td>Microsoft</td>
	<td><a href="http://azure.microsoft.com/en-us/" target="_blank">Microsoft
	Azure</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: #ffaaaa;">Azure SQL Database, Azure
	Cache, Azure Service Bus</td>
	</tr>
	<tr>
	<td>Oracle</td>
	<td><a href="https://cloud.oracle.com/java" target="_blank">Cloud
	Java</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: #ffaaaa;">NOK</td>
	<td style="background-color: #ffaaaa;">Oracle Database Cloud
	Service, Coherence, Oracle Messaging Cloud Service</td>
	</tr>
	<tr>
	<td>Pivotal</td>
	<td><a href="https://www.gopivotal.com/about" target="_blank">Pivotal
	One</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: #ffaaaa;">NOK</td>
	<td style="background-color: lightgreen;">MySQL, Memcached,
	RabbitMQ</td>
	</tr>
	<tr>
	<td>Red Hat</td>
	<td><a href="https://www.openshift.com/" target="_blank">OpenShift</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: lightgreen;">MySQL, Redis, ActiveMQ</td>
	</tr>
	<tr>
	<td>Salesforce</td>
	<td><a href="https://www.heroku.com/" target="_blank">Heroku</a></td>
	<td style="background-color: lightgreen;">OK</td>
	<td style="background-color: #ffaaaa;">NOK</td>
	<td style="background-color: lightgreen;">PostgreSQL, Memcached,
	RabbitMQ</td>
	</tr>
	</tbody>
	</table>
	<br>
	<p>
	Please note that the above list is bound to be out of date almost
	immediately. Some of the offerings have been around for a while, but
	the dynamics in the PaaS space is very high. Just to name an
	example, we should have included the Stratos PaaS, as this offering
	has been donated to Apache last year and been promoted to an Apache
	top level project <a
	href="https://twitter.com/TheASF/status/473781285169938432"
	target="_blank">recently</a>.
	</p>
	<h2>Conclusions and Outlook</h2>
	<p>With the Eclipse Luna relase, Scout adds initial cloud support for
	building enterprise applications. This support makes writing
	scalable business applications as simple as possible. And with
	Scout’s abstraction layer for databases, caching and
	messaging, Scout applications become de-facto independent of
	specific PaaS provider. This let’s you focus on implementing
	functionality and removes the worry of selecting the
	“right” PaaS provider.</p>
	<p>When working with Scout desktop clients, complete scaling is
	already supported with the Scout Luna release. A logical next step
	is to add support for scaling the web servers. As the Scout web
	servers are running the web-clients of Scout web applications, this
	addition will then allow to scale complete Scout web applications.</p>
	<h2>Further Reading</h2>
	<ul>
	<li><a href="https://www.eclipsecon.org/na2014/session/scout-cloud"
	target="_blank">Scout in the Cloud</a> session at EclipseCon, San
	Francisco, 2014</li>
	<li><a
	href="http://searchcloudapplications.techtarget.com/news/2240216336/Eclipse-Scout-Open-source-framework-offers-enterprise-cloud-support"
	target="_blank">Techtarget interview</a> by <i>Caroline de
	Lacvivier</i>, 18 Mar 2014</li>
	<li><a href="https://wiki.eclipse.org/Scout/Tutorial/4.0/Cloud"
	target="_blank">Wiki Tutorial</a> to add Scout cloud support (work
	in progress)</li>
	<li>Other: <a href="http://eclipse.org/scout/">Project Home</a>, <a
	href="http://www.eclipse.org/forums/index.php?t=thread&frm_id=174">Forum</a>,
	<a href="http://wiki.eclipse.org/Scout">Wiki</a>, <a
	href="https://twitter.com/#!/EclipseScout">Twitter</a></li>
	</ul>
	<h2>
	<i>Acknowlegements</i>
	</h2>
	<p>
	<i>This article is based on the master thesis of Thomas Schweigler,
	that has been also supervised by Scout committer Judith Gull. We
	expect to be able to provide access to the full thesis (in German)
	in the near future. </i><i>The cloud icon used at the beginning is
	available at <a href="http://www.iconarchive.com/">www.iconarchive.com</a>.
	According to its <a
	href="http://www.iconarchive.com/show/ios7-style-metro-ui-icons-by-igh0zt/MetroUI-Apps-iCloud-icon.html">terms</a>,
	the icon can be used freely for non-commercial use.
	</i>
	</p>

	<div class="bottomitem">
	<h3>About the Authors</h3>

	<div class="row">
	<div class="col-sm-12">
	<div class="row">
	<div class="col-sm-8">
	<img class="author-picture"
	src="/community/eclipse_newsletter/2014/june/images/mzi3.png"
	width="75" alt="Matthias Zimmermann" />
	</div>
	<div class="col-sm-16">
	<p class="author-name">
	Matthias Zimmermann<br />
	<a target="_blank" href="http://www.bsiag.com/">BSI</a>
	</p>
	<ul class="author-link">
	<li><a target="_blank" href="http://www.bsiag.com/scout/">Blog</a></li>
	<li><a target="_blank" href="https://twitter.com/EclipseScout">Twitter</a></li>
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	</ul>
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