Cloud Computing Expo #1

Today, I went to the 1st Cloud Computing Expo (Cloud Japan) to listen to a talk given by Yuji Chino of NicoNico Video(ニコニコ動画).
Actually, it was the keynote speech of the Data Storage Expo which was joint hosted with that.
That's why, his talk was mainly focusing on storage subsystem perspective of their system.

Here are my notes:
- Nico Video has about 140TB of data in total. Individual video file has 2 or 3 copies including the original.
- At this moment, Nico Video supports only 2 levels of resolution. This is one trade off decision.
- At this moment, Nico Video does not preserve the original uploaded data. This is another trade off decision.
- Nico Video's system uses 3-tier model, edge servers(400), origin servers(100) and storage subsystem(3).
- I'm not sure what is the origin server, but it looks like a kind of cache server.
- Because of their load balancing and multi-tier cache architecture, there is no significant I/O traffic for the storage subsystem even they are using NFS, not FC fabric.
- The edge servers utilizes fast I/O throughput of SSD, for other servers capacity is primarily important.