Welcome to TechScreen

Welcome to the TechScreen site. This side shall support the exchange of knowledge in the domain of Web Engineering and related aspects. As a side effect, this side is used for research on knowledge management technologies. User can pose challenges in the problem domain and can participate in quizzes. Further a bibliography about arcticles in different related domains is continously extended. Finally, questionnaires on different issues are provided. To be able to participate you need an account and a password from TU Wien's TISS system.

Cheap Yet Secure Daily Backups For Database And Files

I need to make backups of a webapplication's MySQL database and some files for a client. Backups should be done on a daily basis and the whole system should be as cheap as possible - "ok, backups are important, but I don't want to spend any money on it anyway...". The backup should be fully automated. Furthermore installing an FTP server on one of the client's local machines (to upload the backups there) is not wanted, due to security concerns.

PostgreSQL Database Backup Takes Too Long

While giving a training course on PostgreSQL, the problem arose that a pg_dump of their database would take too long. The database contains more or less nothing else than BLOBs (PDF files). Currently only 500MB, but there are 45GB of archived files (from the last 10 years or so) and new ones will be added on a daily basis. So at least 50GB (older files could be removed) will be stored in the database. Doing a test dump with pg_dump takes approximately 3 minutes for 500MB (on the given system) - which means 50GB will take somewhere around 5 hours.

Windows SBS2003 Drops Internet Connection

I administrate a small (1 server, <10 clients) network where I deployed a Windows Small Business Server 2003 Standard as domain controller, DNS / Exchange / WSUS / PostgreSQL / ... server, and default gateway (2 NICs). However the internet connection is occasionally dropped.

Using Git DVCS (distributed version control system) and GitHub to effectively collaborate on an open-source software project

While collaboratively working together on an open-source project (which aims to provide a fresh web app framework in this concrete case) and moves at a fast pace it conseqeuntly turned out that using the standard approach of centralized VCS for it soon hit its limits. Therefore, we jointly decided in the community to switch to a decentralized one, namely Git. This DVCS was originally developed by Linus Torvalds for managing the development of the Linux kernel. Its main concept basically is that everybody has his/her own complete "clone" of the code repository.

Setting up a Subversion repository and corresponding Trac app on a (Debian/Apache) server

So the basic problem here is how to best work together productively in a programming/development project and the question which are good tools providing capabilities to potentially support and improve this. One such tool is a version control systems (VCS) which basically helps to keep the code and especially its progress under (version) control in a code repository (transparently). A specific such VCS is Subversion (a.k.a. SVN). This is at the time one of the most popular and up-to-date systems of its kind (i.e., centralized VCS).

Connecting an Authentication Server to a Drupal Content Management System

For my Ph.D. thesis I need a community portal, which supports students to share their experience about internet technologies. It turned out, that the content management system Drupal is a perfect fit to fullfill the given requirements. As usual for a content management system, Drupal also has its own user management function. This means, that students have to register before they may produce content on the portal. Although TechScreen is a software system on a prototype level, it is yet hosted on a server inside the TU computer network.

Oracle and C-Compiling Error

For security reasons a server offering webservices should be installed new: It is used to run CGI-Webapplications manipulating data in an Oracle 8.1.8. database via webformulas. I first installed Solaris and then Oracle 8.1.8 and the webserver. Both are running without errors. In the next step I used the compiled Files from the backup copy: The webservices are running. To modify the applications a new compilation is necessary. I dir not panipulate *.c files. I just tried to compile it. CC or GCC did not work.

Getting WLAN access with iPhone at the university

I have an account jdorn@mobil.tuwien.ac.at that I use on a Laptop to access the closed TUWIS WLAN. In an Internet browser I enter account and password. Then I have access to the Internet for a limited period of time. On my iPhone the entering of the required data is too cumbersome.

Installation of an iCal Server on Mac OS X Leopard

Apple’s description of the iCal Server installation process is very scarce. Apple’s Directory service is required to authenticate users and a correct DNS configuration is required to enable Directory service. DNS is a problem if you have a local network installed with Airport.


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