Successful test of WL v0.4 with 28 users

Thierry Bücheler, on behalf of the "ShanghAI Lectures" project team based at the University of Zurich, has contributed the following guest blog to share his team’s Wonderland experience with the rest of the community.

The Artificial Intelligence Lab at the University of Zurich (UZH), Switzerland, is extensively testing Wonderland 0.4 and 0.5 distributions in order to prepare a global lecture series called the "ShanghAI Lectures" ( starting in October 2009. The tests on the current release 0.4 are necessary since the team runs a "live" pilot (a joint seminar between two Swiss universities), starting on February 26 (and hence running on WL 0.4). In the context of the ShanghAI Lectures, many scientific plugins for Wonderland are written that track avatars (e.g., record voice conversations or avatar’s moving behavior) and allow virtual world researchers to collect data on virtual team behavior.

The test included 28 users on different HW/OS settings and was a success!

Wonderland v0.4 test


Last Thursday a group of 28 people located in different spots throughout Switzerland met in the University of Zurich’s Wonderland world ( to test the server’s performance under such load. Users were using very different HW/OS settings (e.g., Ubuntu 8.10, Windows XP, MacOS X on 32 and 64 bit machines). Some clients were below the minimum specs mentioned here: (e.g., laptop computers with built-in graphic cards without 3D/OpenGL acceleration, running Windows XP on a Duo Core 1.6 GHz processor with 3 GB RAM). One interesting detail to mention: On the 64 bit dual-boot machines that were used, WL 0.4 did run, but only on the Windows installation, not on Ubuntu 8.10 (even though SUN Java was used in Ubuntu).

Users were logged in to the world for about 30 minutes, during which time there was a number of concurrent edits on OpenOffice documents, looking at the built-in video player and webcam application, all whilst chatting to each other through text and audio.

This test run was intended to stress the server in terms of number of users and audio recording. For this, the recording capabilities of jvoicebridge were employed, whereupon each user’s individual audio stream was saved to disk.

There was no issue with avatar control and text chat. Audio worked well until about 23 users were logged in, whereafter it became choppy. The reason for this behaviour is still to be determined, however whilst monitoring the server processes of the sgs, voicebridge and smc client, the sgs server seem to barely be coping, consuming nearly 100% of the cpu cycles whilst the voice-bridge consumption was only about 10-15%. The max CPU usage was at 140% with 28 concurrent users.

The server that was used has the following specs: Intel Pentium Core Duo CPU 3.40Ghz, 4 GB RAM, running debian etch.

The "ShanghAI Lectures" project team


One Response to Successful test of WL v0.4 with 28 users

  1. Miriam says:

    I recently came across your blog and have been reading along. I thought I would leave my first comment. I don’t know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.

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