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Operational Concept and Technical Documentation

IT support for, and maintenance of, the server is provided as a continuous task by GESIS’ Knowledge Technologies for the Social Sciences (WTS) Department. If you have any questions about the technical infrastructure, please contact Mahan Zolghadr. The institute’s Computational Social Science (CSS) Department (Knowledge Discovery Team) is responsible for indexing. Uta Richter or Thomas Müller can provide information on indexing.

In September 2012, SSOAR was moved to a dynamic cloud server of the provider 1&1. Within the framework of the move, SSOAR was converted to the open source software DSpace.


At the time of moving, the server was assigned a main memory of 8 GB, a hard disk size of 800 GB and two CPU cores. For its service, the provider uses a virtual server farm with AMD Opteron processors. The configuration can be extended during operation as circumstances require, so that future demands on the system can be responded to.


The server is run with the operating system Ubuntu Server 10.04 LTS. The system comprises two main components: a Typo3 instance for the editorial pages on the basis of PHP5 and a Tomcat 6 for the repository software DSpace. A MySQL database is operated for the Typo3 and a PostgreSQL database for DSpace.

Access to the systems is protected via personal identification codes. Access to the remote console is possible only by means of an SSL key and a user identification code.

Backup and Maintenance of the System

The databases are automatically saved every three hours. Incremental backups of the system are carried out on a daily basis and a complete backup is performed once a week. The data are backed up on internal GESIS data storage media, thereby ensuring the separation of server and backup. Security updates are carried out automatically and in a timely manner. If the system should fail, it can be reconstructed within a day with the standard software after the backed-up data has been imported.