The client applications layer contains the actual application as a web browser on the user's machine; basically the presentation layer. Out of the box Alfresco provides two client applications: Alfresco Explorer and Alfresco Share. Alfresco Explorer is pure document management web application whereas Alfresco Share is Web 2.0 application which provides dynamic collaborative support. In the next couple of chapters we will talk about these two applications in detail. Along with these two applications, Alfresco provides the support for CIFS, FTP, WebDAV, Microsoft Office, and so on. Refer to Chapter 9, Integrating External Applications with Alfresco, for more information on the different client applications integrated to leverage the services provided by Alfresco.

The repository services layer consists of Alfresco components and services. This new architecture has clear separation between the presentation tier and the repository tier. The Alfresco RESTful API provides access to its services via HTTP which makes it accessible to other tools and applications. The SharePoint protocol support offers Microsoft users greater choice by providing them with the first open source fully-compatible SharePoint repository. Companies can leverage existing investments in Linux, Java as well as Microsoft .NET connection software to significantly reduce their SharePoint total cost of ownership and maximize their hardware and software investments. The Content Management Interoperability Services (CMIS) specification defines a domain model and a set of API bindings, that can be used by applications to work with one or more enterprise content management repositories or systems.

The data storage layer stores the data in a relational database and filesystem.

There is a reason for using both database and filesystem as content storage. Any content within Alfresco consists of two elements, the content itself and information about the content (metadata).

The actual content can be anything from simple documents (HTML and XML) to images, audios, and videos. The actual content and its related versions are stored as binary files in the filesystem. Storing content on a filesystem has its own advantages. It allows for very large content, random-access streaming, and options for different storage devices. It is important to note that Alfresco is agnostic with respect to the filesystem it utilizes. It is possible to configure Alfresco to use a vast diversity of filesystems.

Alfresco uses Lucene and Solr, popular open source search engines, to provide metadata search and full-text search capabilities of the content. Apart from the actual binary content, indexed files are also stored on the file system.

The content metadata consists of information which includes elements such as:

The application server hosts the user interface and domain logic. It provides an abstraction and enables communication between the client and storage layers. In the case of Alfresco, the application server houses Alfresco applications (such as the Alfresco Explorer and Alfresco Share) and the Alfresco repository.

The Alfresco repository provides a set of reusable cross-cutting content management services such as content storage, query, versioning, and transformation, which may be utilized by one or more applications.

An Alfresco application provides a complete solution tailored for a specific area of content management such as document management and records management. The user interfaces for all these applications are referred to as Alfresco Explorer and Alfresco Share. Alfresco Explorer is the JSF-based client, which is highly customizable and configurable according to the user specific requirements. The out of the box web client gives you a lot of packaged functionality. With the web client management console, you can manage users, security, content, business rules, and so on. Additionally, Alfresco Share introduces a new, simplified, easy-to-use, and adept knowledge worker UI; the current JSF client will still be available and unchanged.

There is no installation or configuration required for the Alfresco user interface. Any number of web browsers can connect to the application without prior client installation costs.

The out of the box installation comes with Alfresco Share and Alfresco Share web client where you can connect to the Alfresco repository through web-based applications.

Apart from these applications, Alfresco out of the box installation supports various client applications to access Alfresco content with web services or protocols such as FTP, WebDAV, and CIFS:

Alfresco currently provides two types of product download options:

Both the options have the same code base and features, and are 100 percent open source. For both the options, you can use Alfresco documentation (wiki), community support (forums), and community contributed add-on products. Alfresco Community Edition is free. Alfresco Enterprise Edition includes per-CPU license fee.

The Alfresco Community Edition is an unsupported product and is mainly designed for developers and technical enthusiasts in non-critical environments. Alfresco Community Edition releases early, often, and renders a daily build, offering the latest functionality. It doesn't provide scalability and high availability certifications. Community editions are not updated with the latest bug fixes; those are provided in the Enterprise editions. A feature such as JMX tools support is also not available with the Community Edition.

I would recommend this to use as the research vehicle for new features and as the platform for the Alfresco Community and consider it as a test drive before you install.

If you are implementing Alfresco for major corporations, financial, insurance, government, or healthcare organizations, I would recommend you to go for Alfresco Enterprise Edition support. The primary benefit is that with the support of Alfresco and its certified partners you would get a stable, reliable, certified, and supported application with warranty and indemnity. Your Alfresco version will be certified on all available stacks such as Linux, Windows, MySQL, and Oracle. You will benefit from Alfresco support which includes problem resolution, compatibility advice, and migration advice and upgrade support. You will receive 24 x 7 support from Alfresco experts for mission critical applications. You can know more about Alfresco support stack by going to http://www.alfresco.com/services/subscription/supported-platforms.

Choosing an operating system to run Alfresco will be based on various factors. For some companies it depends on in-house expertise. For example, if you have administrators and IT staff who can easily manage business applications running on Microsoft Windows platform, then your choice could be to go with the Windows operating system. For some companies it is based on the integration requirements with the existing systems.

If you do not have any preferences, I would recommend you to go with the Linux operating system for production use. Linux source code is freely distributed. Tens and thousands of programmers have reviewed the source code to improve performance, eliminate bugs, and strengthen security. No other operating system has ever undergone this level of review. The key advantages of Linux are listed as follows:

The data access layer of Alfresco is implemented using an open source software component and ORM (Object Relational Mapping) tool called MyBatis. If you have already chosen the Microsoft Windows operating system, then the natural choice for you could be MS SQL server. If you already have Oracle license, then Oracle database is the best choice for you. You will get PostgreSQL by default with the Alfresco installation.

If you do not have any preference, I recommend that you go with the MySQL database which costs nothing if you go with the open source version. The MySQL database has become the world's most popular open source database because it is consistent, and also because of its fast performance, high reliability, and ease of use. It's used in more than 10 million installations ranging from large corporations to specialized embedded applications. MySQL runs on more than 20 platforms including Linux, Windows, OS/X, HP-UX, AIX, and Netware, giving you the kind of flexibility that puts you in control.

Alfresco runs on any J2SE 5.0 complaint servlet container. Hence there are no application server specific dependencies. However it is important to make a choice of the application server before moving into production.

Alfresco uses the Spring framework and not the Enterprise Java Beans (EJB) framework. So there is no dependency on JBoss or any other application server which provides the EJB container. Spring is an open source application framework for Java/JEE. The Alfresco repository uses the Spring framework as the core foundation of its architecture. If you are developing a standalone application, then Tomcat might be a good option. Apache Tomcat powers numerous large-scale and mission-critical web applications across a diverse range of industries and organizations. It is the most widely accepted web servlet container in the market.

On the other hand, you must consider using JBoss application server, which has the highest market capture (> 35 percent) in J2EE-based application servers in the world. JBoss internally uses Tomcat and hence you get the benefits of Tomcat servlet engine as well.

Alfresco application is implemented in a way to utilize JBoss cache's ability to distribute and maintain data caches, making it possible to build large-scale systems that outperform traditional enterprise content management systems. Alfresco also utilizes the clustering, failover, and load balancing facilities of the JBoss application server to increase scalability. Alfresco uses JBOSS jBPM tool and Activiti for business process management features.

If you have already invested in JBoss, then Alfresco provides complementary industry-leading enterprise content management technology to the JBoss enterprise middleware system suite.

It is optional for you to go with a portal of your choice; if you already have an enterprise portal you can integrate Alfresco with it. If you do not have a portal in place and you would like to leverage the portal framework, then you can consider using either JBoss portal or Liferay portal. Both of these are based on J2EE technology; both of them are open source and open-standards based and both of them have Alfresco built-in support.

The JBoss portal provides an open source platform for hosting and serving a portal's web interface, publishing and managing its content, and customizing its experience. While most packaged portal frameworks help enterprises launch portals more quickly, only JBoss portal delivers the benefits of a zero-cost, open source license combined with a flexible and scalable underlying platform. The JBoss community portal project no more exists. It's been managed by JBoss community and GateIn. The new portal introduced with their combined effort is known as the GateIn Portal framework. You can read more about this from http://www.jboss.org/gatein.

Liferay is the most downloaded and popular open source portal with 40,000 downloads per month. It runs on top of any J2EE servlet such as Tomcat, so a full installation of JBoss is not required, but it can run against most full application servers out of the box including JBoss, JRun, BEA WebLogic, and Orion. It has a full set of web service interfaces to the portal. Liferay supports more than 800 portlets (products) and has wider adoption in the market.

You need to make the best choice of software to install Alfresco. If you do not have any specific requirements, you might consider a complete open source stack for production usage and go with the Alfresco Enterprise Edition on the Linux operating system, with MySQL database running on the JBoss application server with the Liferay portal.

The examples in this book were created and tested with the following choice of Alfresco installation:

The default installation of Alfresco software requires installing the windows enterprise version alfresco-enterprise-<version>-installer-win-x64.exe downloaded from the SourceForge project location (http://wiki.alfresco.com/wiki/Download_and_Install_Alfresco). Now Alfresco is hosting its own community download area. You can also download this from http://www.alfresco.com/products/ecm/enttrial/. Select the download package. And you will be asked for the user name and password of the Alfresco content community.

At the time of writing this book, the latest version was Alfresco Enterprise 4.1.2 and installer file alfresco-enterprise-4.1.2-installer-win-x64.exe is approximately 470 MB in size.

This installer will install:

To install and run Alfresco, you need at least 500 MB disk space and at least 512 MB RAM on the desktop or server.

The following steps are a simple way of installing all software and components required to run Alfresco through the installation wizard:

This section contains the installation steps to configure Alfresco on Tomcat. Alfresco requires JDK to be already installed on your machine.

Alfresco uses various open source components for different purposes. You can install and configure them based on your business requirements. In this section we will see how to install those components and configure it with Alfresco.

Let's take a peek into the installation directory <alfresco_installation_folder> to look at the folders:

You can uninstall the program by clicking on the uninstall.exe application.

The options for starting and stopping Alfresco as console application can be viewed by navigating to Start | All Programs | Alfresco Enterprise | Alfresco Enterprise Service as shown in the following screenshot:

The options are as follows:

Alternatively, you can always start, stop, and restart the Tomcat application server, and the MySQL database server manually, by going to their respective directories. It gives more control to the user. However, the console option gives batch files to perform the start/stop procedures in a consolidated way, relieving the user of any unwanted errors.

You can also configure Alfresco as a Windows service in a standard Alfresco/Tomcat installation. With the default installation, Alfresco is bundled as a web application that launches within Tomcat. To configure Alfresco to run as a Windows service, you need to set up Tomcat to run as a Windows service.

Steps to configure Alfresco as a Windows service

Alfresco supports the German (de), English (en), Spanish (es), French (fr), Italian (it), Japanese (ja), and Dutch (nl) language packs in translations. On complete Alfresco installation, all the language packs get installed by default. If you want translation support which is not supplied with Alfresco installation, then you need to install the TinyMCE language pack. Use the following steps to install the language pack manually:

For installing any AMP module in Alfresco, please refer to the following steps:

You can apply the module file to alfresco.war using the command prompt. You can use the following command to apply the AMP file:

java -jar alfresco-mmt-2.1.jar [args]

In order to use this command you need to set some JAR files on the class path. Run the <alfresco_installation_folder>/scripts/setenv.sh file before running the previous command to set JAR files on the class path. You will also have to set the ALF_HOME and CATALINA_HOME environment variables.

Let's understand the commands you can get with the MMT tool.

You can use MMT with Maven as well. You can visit http://wiki.alfresco.com/wiki/Managing_Alfresco_Lifecyle_with_Maven for more information.

Some of the extension modules available with Alfresco are alfresco-enterprise-spp.amp for SharePoint protocol support, alfresco-fb-doclib.amp for Facebook integration and alfresco-recordsmanagement.amp for Records Management sample functionality.