10,000 users watching VOD is a fairly large number of simultaneous customers for most (general content) providers, but it can be done using current technology. It will mean investing in the right network connections and building a well architected and tested configuration. No p2p is required so you can continue to maintain control of both your content and your viewer (not to mention that you won't have to worry about anyone blocking/denying your attempts to send over a p2p link).
For example, we have data from a (dated) configuration posted in our FAQ showing that with just 2 cores, 2 GB of RAM, 2 data hard drives, and a 1 GbitE connection, we were able to use 400 randomly selected files to establish 700 connections:
and use our testing tool liberally (the tool is available by sending email to test[at]
Watch your I/O patterns closely- if your working set of VOD files is very large, you may need to invest in either software which provides storage device caching (according to tests at Oracle's Sun benchmark labs, their ZFS will provide useful caching of data in RAM). We have other customers who simply bought a pool of SSD units large enough to hold their working set of files. Storage tuning is required because the workloads faced by any storage product have traditionally been way too widely varying to ensure high end out-of-box performance.
If you need further guidance in tuning, I've found that most of the top-tier hardware vendors have benchmarking labs and competency centers where they have staff who are more than happy to ensure that you're getting maximum performance out of their gear. That being said, they will need you to setup the load testing tool in advance to provide data gathered of your most intense I/O access pattern (since running a video server looks quite different from running a database).
If you need an introduction to the HW vendors, just send an email to sales[at]wowzamedia[dot]com (include the contact info for your current sales team contact at that vendor to ensure your inquiry gets tracked & escalated).