International Symposium on Distributed Computing and Artificial Intelligence 2009International Symposium on Distributed Computing and Artificial Intelligence 2009

Optimizing the Use of an Integrated LMS: Optimizing the Use of an Integrated LMS:

Hardware Evolution through Distributed ComputingHardware Evolution through Distributed Computing

Experience from the Experience from the Universitat de ValènciaUniversitat de València

Paloma Moreno-Clari, Sergio Cubero-Torres, Agustín López-Bueno

• Introduction

– Current technologies offer almost unlimited and ubiquitous access to contents and they help to improve interaction

– However, the provision of top ICT infrastructures and tools does not ensure the fulfillment of educational objectives

– Adequate use of these tools that results in a more efficient instruction

– Plans and actions must be added to equipment and applications

Universitat de València

Hardware four years-evolution to achieve an integrated LMS for all the university community, using distributed open and collaborative hardware

• Selection Process, Implementation, Integration and Functionalities’ Improvement

– The University of Valencia is one of the largest in Spain

– 2003: The university already counted with an important ICT infrastructure

• not integrated under a single platform• it was decided to integrate all these applications under a

single LMS

– Exhaustive survey of the available platforms • Availability• Standardization• Integration• scalability

• Open Source .LRN project

• A single access point for many of the existing applications

• The LMS offered a number of useful services to the academic community

• Functionalities were provided for each module:

– document repository– event calendar– news section– possibility of creating forums– e-mail and chat services– support for notifications– submission of homework– repository for learning objects– application to create Web presentations, weblogs– photo album and a FAQs section

• Distributed Hardware and Evolution

– Firstly implemented over two servers with AMD Opteron dual

processors and operating system Debian GNU/Linux

– In one of these, the AOL web server and the .LRN application were installed

– In the other, it was installed the PostgreSQL (7.4) database, based in Open Source

– All hardware changes and evolution decisions have been made taking into account the academic community size, the best performance solutions and the previous experience in such problems of other .LRN community members

• The First UV LMS Cluster (Academic Year 2005-06)

– The progressive LMS implantation, in the Universitat de València particular case, has led to an exponential increase of simultaneous accesses

– Scalability problems

– The application server inability to manage great memory

– Application and performance mistakes

– It was decided to install a device to balance the workload between two web servers; to change the Operating System to a 64 bits version; and to rewrite the consultations’ logic.

• Growth and Stability (Academic Year 2006-07)

– In the first four-month period of the academic year 2006-07 there were made changes in the hardware configuration:

• the incorporation of an Apache server to deliver the static elements• the database server updating PostgreSQL 8.1.

– It was installed a high availability and high performance cluster, and there was improved the device to balance the workload between the web servers

– This architecture distributes the application server and the web server work between different machines

– The main problems of this configuration were cluster nodes synchronization failures that forced the modification of some code parts

• Virtualization and Availability (Academic Year 2007-08)

– Improvements: • The number of cluster elements was increased to six

• The web and applications servers were virtualized to simplify its maintenance and the new elements management

• A multimedia server was integrated in the general architecture to stimulate the multimedia contents creation at the platform

• Conclusions and Future Work

– At Universitat de València it’s remarkable the experience with an open source tool and the collaboration work in a world-wide developing community

– Universitat de València is one of the largest in Spain adopting an open source platform linked to educative innovation for blended learning, integrated with preexisting systems, and for the use of all academic community

– It constitutes the world largest .LRN implementation fully open source (.LRN on top of PostgreSQL).

• Conclusions and Future Work

– Changes and hardware evolution by using distributed computing, have improved the access quality and the system workload

– Other changes alternatives, as database replication, combined hardware and software load balancing or cluster elements virtualization have been considered, but there not were taken because they need a more in depth study and research, which is currently being made

– The UV platform changes which may be applicable to other .LRN personalization will be made available to the community. So, the .LRN architecture and its functionalities will be continuously improved