- New Subsystems
- Storage Policies
Subsystems are mini-servers that run embedded within the overall Alfresco system. They are independent processes that can be brought up and down. This design lets an administrator of the system change a single configuration without having to bring down the entire Alfresco system. The advantages are reliability and availability.
Subsystems can be configured via any JMX client [Enterprise Alfresco only]. In the demonstration, Paul used JConsole, a common JMX console used by the JDK. From the console, the subsystems can be stopped and started, and parameters of the individual subsystems can then be reconfigured.
Starting in Alfresco 3.2 the file alfresco-global.properties is a centralized place for system configurations -- unless you are using JMX. If you are using JMX, the alfresco-global.properties file values are used until you configure new subsystem values via JMX. JMX changes get stored in the database, and thereafter, any time you start your system, the database values will override those of the properties file. An advantage of this approach is that system changes are stored in the database and easily propagated to all servers in a cluster. But the properties file is not updated and may lead to confusion about what system values are currently being used.
Examples of Alfresco Subsystems include:
- File Servers
- Third party
- WCM Development Receiver
- OpenOffice Transformations
Paul gives a good detailed example in the demonstration of how he could stop the OpenOffice Transformation subsystem, configure a second one, and then start up two OpenOffice Transformation subsystems.
Storage Policies were covered in the second portion of the webcast. (There is also an Alfresco brief description of Storage Policies here.) Storage policies can be part of an Information Lifecycle Management (ILM) strategy. They let the administrator determine which content should be stored where.
Paul shows in the webcast an example where he automatically stores content to a particular location based on content type -- or whatever other criteria you might have. He accomplishes this by setting up rules that get run when the content is checked in. Images, videos, and PDFs, for example, could all be stored in separate directories or volumes.