So just how many people watched the first ever live stream of Christmas in Christ Chapel this year? Well, that is a tough question to answer. It seems like that should be a pretty straight forward and simple answer. Just count up the number of requests for the video file from our systems logs and call it good right? Unfortunately it is not that easy.
Gustavus does not have unlimited bandwidth so there are only so many connections to our live stream that we can handle on our own. The HD version of the stream this year required about 4Mbit/s per viewer. We have about 800Mbit/s of bandwidth we can use for sending this out to the world so that means we can handle about 200 simultaneous viewers of the 720p HD stream before we run into trouble. Since we were expecting more that 200 viewers from around the world, we had to come up with some other way of getting that video to more people.
Our intenet connection during C in CC
So how did we do that? By sending our live video feed to YouTube and then directing most people to the embedded YouTube player. That way we only send out 1 copy of our video stream to YouTube and then let them handle distribution of that to the world.
We know that not everyone can view YouTube as some schools, businesses, etc. block YouTube and others may have issues with it for some other reason. So for these people we allow up to about 150 of them to connect directly to our local streaming server. Knowing that we could also potentially hit that limit ( we did ) we also set up an alternative method of connecting to the stream. In this case, that was done via Amazon’s CloudFront. CloundFront connects to our local streaming server on behalf of clients around the world and caches the video, taking much of the load off our internet connection.
So, to answer the original question about how many people watched the event we have to combine data gathered from all these sources, and even then we need to make some educated guesses. YouTube gives us some pretty good numbers. From their system we can see that we had up to ~1300 concurrent users at the peak and combined everyone watched ~2200 hours of streaming video as well as a total of ~4000 playbacks from 23 countries and 49 states.
Graph of viewers to the YouTube live stream
The data from our Amazon stream combined with the data from our local server are a little more difficult to parse but we do know a couple things. Our flash player recorded ~1600 unique viewers and ~4000 video plays to 24 countries. Amazon says that we used 1.2 TB of data. We know from Youtube that about 1/3 of our users watched the 720p stream, 1/3 watched the 480p stream, and 1/3 watched the other streams. From that we can guess that we averaged around 600 concurrent viewers for 2 hours via Amazon.
So here is where things get a little more difficult. How many users started with the Amazon stream and then switched to the YouTube stream? How many went the other way around? So how many “viewers” may have been counted in more than one way? That is something we will never know for sure as Amazon and YouTube don’t supply us with enough data to know that. We can guess that combined, we had about ~2000 concurrent viewers averaged over the 2 hour period. We can also tell from Google Analytics and our own logs that we had about ~3800 unique viewers to the streaming page. That does not count the users that went directly to our YouTube page.
Finally, we don’t know how many people were behind each of those viewer connections. We know that in many cases one “viewer” was actually a family watching the stream and in some cases even a room full of people. We have a little bit of an idea from the people who filled out a survey as to how many people were watching with them. So from all that information, we can guess, conservatively, that we probably had around 7,500 people tuned in to watch at least some of the live stream. And from the feedback we got via Twitter and Facebook, there were a lot of happy, excited, and appreciative viewers from all over the world who were very pleased with the results.