Does anyone here know how the servers for iPlayer really work? The problems with any on demand media server are that they don't necessarily scale up well as the number of users increases. However, if all users are watching, or listening to different things, then effectively each user has his/her own direct dedicated connection to the server, so the server load increases, as well as the data communications traffic. N users require N times as much resource as a single user.
Schemes such as pyramid broadcasting can be used for popular items, and band width skimming is a technique which can be used to allow many users to use the same server with perhaps logarithmic scaling on the communications requirements. Log scaling would allow N users to require only log N times as much resource as a single user - for some suitable log base. Thus 1 million users (unlikely for R3) might require only 20 times as much resource as one user - assuming base 2 and other factors probably ignored. However, log scaling is definitely good news for servers and communications channels, providing the interaction between the client and server is not too complex.
The use of multicast distribution channels can also help quite a lot, as well as faster than real time for playback channels. With some compromises on what is possible, scaling can become independent of the number of users above a certain number. For example, 20 multicast channels may suffice for any number of users. The compromises may prevent skipping to any arbitrary section of the media, though.
Depending on which approaches are used by the server (hybrid approaches are possible) the software in the media players must clearly match the algorithms and processing in the server.
So, who knows?
Schemes such as pyramid broadcasting can be used for popular items, and band width skimming is a technique which can be used to allow many users to use the same server with perhaps logarithmic scaling on the communications requirements. Log scaling would allow N users to require only log N times as much resource as a single user - for some suitable log base. Thus 1 million users (unlikely for R3) might require only 20 times as much resource as one user - assuming base 2 and other factors probably ignored. However, log scaling is definitely good news for servers and communications channels, providing the interaction between the client and server is not too complex.
The use of multicast distribution channels can also help quite a lot, as well as faster than real time for playback channels. With some compromises on what is possible, scaling can become independent of the number of users above a certain number. For example, 20 multicast channels may suffice for any number of users. The compromises may prevent skipping to any arbitrary section of the media, though.
Depending on which approaches are used by the server (hybrid approaches are possible) the software in the media players must clearly match the algorithms and processing in the server.
So, who knows?
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