MySQL and HeatWave

  • Sun
    October 24, 2008

MySQL University Using Dimdim

Stefan Hinz
MySQL Documentation Manager

After a series of tests, we've just conducted the first MySQL University session using a new conferencing system, Dimdim, and I thought I'd let you know how it went.

MySQL University is an educational program for engineers from Sun/MySQL and the MySQL community, Dimdim is the new conferencing system that we hope will be able to replace our old presentation system, and "we" isn't plurale majestatis but rather refers to the guys running the MySQL University program, the Sun Database Group documentation team.

I started the Dimdim session fifteen minutes before the hour, and when the two presenters arrived we did a sound check. Petr and David connected from Sun offices in Prague, Czechia, and California, respectively, and I was on a DSL line in my home office in Berlin, Germany. Sound quality was excellent, as if Petr and David were standing next to me. Other attendees confirmed that sound was great for them, too, and also reliable (very few drop-outs). Speaking of sound: Dimdim doesn't require you to use a telephone for the voice channel (although you could) – it's VoIP, straight over the Internet and out of your browser's Flash plugin. It's VoIP for presenters, too – all you have to do is allow Flash to access your microphone, and your voice can be heard. If you have a camera attached you could also video-stream your face, but we haven't tried this.

David sharing his desktop to demonstrate using MySQL with NetBeans

What worries me is that my own voice sounded like I was a chipmunk (or, as David put it, as if I had inhalated helium). The day before, in one of the many test sessions I ran, my voice was okay, but then I was sitting in the same room where my wireless access point is located. This time, I was sitting in a room next door, in an effort to reduce sounds from my children playing. Looks like connection quality is extremely important for Dimdim's VoIP, at least on the "active" side – just for listening it didn't make a difference when I was on a signal-wise low-quality wifi (at other test sessions we did). I'm not sure how this will work out for presenters who are on less-than-optimal Internet connections.

There were twelve people in this session, including presenters and host. I asked them where they were from, and it turned out they were from all over Europe and North America (see screen shot). One participant was from Japan. Since no one was reporting anything but minor problems, this indicates that Dimdim works well in many places on this planet.

Petr and David showed some slides. Currently you can share PowerPoint and PDF. It's quick for both presenters and audience, and the user interface for presenters is functional and slick. They also shared their desktops to demo NetBeans – desktop sharing requires a browser plugin that's available only for Windows and Mac OS X, but the Dimdim folks claim that they're working on a Linux version, too. Desktop sharing is kind of slow, but as long as presenters keep in mind that redrawing on the receiving end takes some time I think it's good enough. For presenters, it's a bit of a challenge to arrange their windows in a way that they can still see the Dimdim chat sidebar (so they can see questions), and also they should use only a small part of their screen because otherwise the audience will have to scroll in the shared-desktop area in order to see everything. From what I know Petr and David used a resolution of 1280x1024, and they demoed in the upper left two thirds of their screens. I could see everything they did in my full-screen browser window without having to scroll.

Now for some bad news:

  • "Active" voice stopped working for me after a few minutes. I noticed when Petr rudely ignored and interrupted my talking, but it turned out that Flash had stopped capturing my voice. Being the host, I couldn't just restart my browser, or the meeting would have ended surprisingly for everyone. (I still have to find out if that's really the case or if I'm just paranoid.)
  • Recording has severe limitations. For one thing, not everything is recorded. According to Dimdim, audio and video of the presenter is recorded, and so is the chat log. The shared area is recorded only for presentation slides. Shared-desktop sessions and whiteboard scribblings aren't recorded. What's worse, you can only record one presenter. Had I recorded Petr, the recording would have stopped after assigning the presenter status to David. Restarting recording would have resulted in Petr's recording being overwritten by David's. Lame. So I resorted to just recording David's part of the presentation. After the session had ended, I received an email with a link to the chat log. And that was it. No link to the voice recording. Maybe the session wasn't ended properly (see next bullet item) and thus some trigger on Dimdim's side didn't fire, I don't know. I've reported the problem to the Dimdim folks.
  • Firefox froze after I clicked "end meeting". This has happened before, and I suspect it's due to Flash doing bad things to my browser. Nothing major, though, since it only happens when the session is over, anyway, and thanks to Firefox' excellent crash recovery it's back with its previously opened tabs within seconds.
  • I'm on Linux (for this particular session, on 32-bit Linux). Multimedia applications often favor Mac OS X and Windows to an extent that Linux users can only hope that things will work at all for them. Not so Dimdim – they've done a remarkably good job for Linux users. Still, there's that feeling that things are less smooth and reliable on Linux, but I guess the Dimdim folks can only do so much about it, since most of the issues will likely have to be resolved by the makers of Flash.
To conclude, I'm quite happy with how this session went. I'm curious to see if things will work out similarly well for other presenters, particularly if they're on Linux. Time will tell.

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Comments ( 2 )
  • gerard Friday, October 24, 2008

    very interesting, but is there a chance to have it working on (open)solaris?


  • Stefan Hinz Monday, October 27, 2008

    Thanks for pointing this out! Seems like Dimdim is refusing anything other than Mac OS X, Windows, or Linux. We've filed a bug.

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