Understanding where DSpace content is stored
DSpace repository content consists of a database and files known as assets. The database acts as a fast index and the asset object data is stored as files in their native format but without an extension.
In addition to importing the SQL dump into the database obtained from the University of Nottingham, we need to copy over the corresponding assets. Should there be a delay in obtaining the SQL dump and the assets it is possible that they may not be synchronised. It may be worth taking the source site down to prevent editing whilst exporting the content. The asset files contain item content but also other information such as licence agreements. Although we took the assets at the same time as the SQL dump, when cross checking, we found the number of asset folders was greater than the number of items in the SQL dump.
DSpace Installation Key Locations
There are three important locations in our DSpace installation:
- The source release directory.
- The DSpace build directory and
- The Tomcat directory.
1. DSpace Source directory
The location of the downloaded DSpace source code. After unpacking the full source download this folder will be named after the DSpace version number e.g. dspace-1.7.2-src-release/. Most changes to the DSpace configuration require that it is rebuilt.
Any changes to the working web application therefore must also be made in this location.
2. DSpace Build directory
The DSpace build directory is populated when DSpace is built or rebuilt from the source code. The DSpace Web application is output to the location specified in [DSpace source directory]/dspace/config/dspace.cfg. This can be thought of as being the compiled working application. The asset files with item content are stored here.
3. Tomcat directory
Named after the version of Apache Tomcat e.g. apache-tomcat-7.0.11. Tomcat is the Web Server that provides a Web interface to DSpace. In our implementation, the Web Application in the build folder is copied into the Tomcat webapps directory. (Copy the folder [DSpace build directory]/webapps/xmlui to [Tomcat directory]/webapps/). The XMLUI Web application interacts with the DSpace application in the build directory.
Tomcat can be configured to point directly at [DSpace Build Folder]/webapps. This would seem simpler than having the copy of webapps – but it does require changing the default Tomcat configuration.
The ELOGeo asset files go under the [DSpace build directory]/assetstore/. Inside will be a number of numeric directories containing the repository content. When DSpace is rebuilt this content will not be deleted. It is not necessary nor a good idea to copy back the files to the [DSpace Source Directory] because the files in the Build Directory are the current live files.
Several themes are available for DSPace. The ELOGeo repository uses a variation on the Mirage theme. This determines the look and feel of the DSpace interface using XSL, JS and CSS files to control the layout and styling of the HTML markup. If any changes are made to the live Web application, it is important that they be copied back to the Source directory so they will be incorporated in future builds. The theme files will be present in thre locations:
- Source Code: [DSpace source release directory]/dspace-xmlui/dspace-xmlui-webapp/src/main/webapp/themes
- Application: [DSpace build directory]/webapps/xmlui/themes
- Tomcat copy of application: [Tomcat directory]/webapps/xmlui/themes
To use a specific theme, in our case “elogeo”, the configuration file needs to be amended:
DSpace source directory]/dspace/config/xmlui.conf
This required theme needs to be the last entry in the <themes> element.
<theme name=”[Theme name]” regex=”.*” path=”[theme directory name]/” />
DSpace will need to be rebuilt for the changes to take effect. It is possible to edit the theme in use without rebuilding DSpace. This will be outlined in a later post on editing themes.
This work has enabled us to gain an understanding of how and where DSpace stored content and how the layout of its interface can be customised.
This demonstrates that there is a relatively easy way of copying one instance to another using the database dump, asset files and some configuration changes.
The relationship between the three file locations isn’t at first obvious. It is crucial to understand which files need to be copied back to the source code and which files shouldn’t be copied back to the source code so they can be incorporated into future builds.