Today I am going to explore the second part of interactions within BBB. As i said before when user does something with Big Blue Button the information is sent to the web server, and web-server sends it to one of the two places either to bbb-web or bbb-aps.
In this post i will be writing about bbb-web. bbb-web is used for every not audio or video actions inside the BBB. As an example it is used to schedule conferences, login/logout, retrieving/saving data to database, also to work with uploaded data. So as i found out from the Video Tutorial bbb-web is a Grails application. And Grails is Java based web-app framework. “bbb-web” stands on top of Tomcat servlet container.
Also “bbb-web” uses MySQL database that keeps information about all data used in BBB (e.g conferences time, user info etc.).
bbb-web uses 2 converters they are named as “SWFtools”.Swf tools are used to convert pdf or png presentations, that teacher uploads, into “swf” format, otherwise students won’t be able to see presentations . The action in the Video where user uploads a presentation and it is seen on the website is done by bbb-web that receives png or pdf data and converts it to the flash swf format.
To create thumbnails of the presentation is used tools called Imagemagic and GhostScript, the second task of Imagemagic is to work as SwiftTools in case they fail to convert presentation for any reason. I guess that Imagemagic is not used primarily for this task because small converters work faster.
The last thing in this post i want write about is a tool s called “activemq“. ActiveMQ is an messaging server that through Java scripts sends information about convertion status bbb-web and bbb-aps (I will talk about bbb-aps in the next post). It is needed to track errors and make the communication between two essential components of BBB.
This is it for now about the bbb-web. In the next post I am going to get in depth about bbb-aps and how it interacts with the whole system.