Web Hosting Talk : Web Hosting Main Forums : Dedicated Server : Concurrent Video Streams

[Perfecthost]

I have a client that is not satisfied with answer I have given him on a certain point. He wants a dedicated server to host short movies, as he is part a short film (non-adult ) web enthusiasts group. He wants to know how many concurrent video streams he can deliver without crashing the server.

The server he is asking about is:

Pentium 4 3.2 Ghz with 800Mhz FSB, 1MB L2 cache HT
2 GB RAM
Cpanel

I have talked with several other hosts, but query your expertise. Here is his email:

...we're using the site mainly to stream video. Some
organizations we're working with are organizing email campaigns
around our site, and we want to be careful about the server capacity
and not putting ourselves in a position of crashing the server.

For instance, if an email is sent out to hundreds of thousands of
people at one time, and a few hundred click the link to watch video
on the site at the same time, can the server handle that? If so,
great. If not, we'll still send the email, but distribute the mail
over a few days and spread out the response. But we need to have an
idea of what the server can handle in serving video at one time
(similar to saying the server can handle X amount of hits at once.,
but taking into account the extra load of video). We don't
particularly care whether it's a thousand clicks on one video or
three hundred clicks on three videos at the same time, we just want
to know what the server can handle as far as how much video it can
stream at one time, and we'll allocate our marketing accordingly.

What do you think?

[ComplexDrive]

I would need to know what bit rate he wants to stream, what type of connection does the server have?

[Xandrios]

First of all: I wouldnt quote an email of a client on a public board.

There are two main factors here: Bandwidth and CPU power. Take the max troughtput (100Mbit for example), devide that by the stream bandwidth (i.e. 512Kbit), and you know how many concurent streams the connection can handle.

The CPU part might also be a factor. It depends on how the videos are served. If people can just download them, and a webserver like Lighttpd (www.lighttpd.net) is used, the CPU will be fast enough to utilise hundreds, maybe up to a thousand concurrent connections. If some other tool is used, ie, Real Media server...then you probably need more CPU power. But how much you need....you'll only find out by testing.

But if its just plain serving files: I push 100Mbit with a P4 2.4Ghz using Lighttpd, while server load stays below 0.5. So plain files is no problem at all. (In that case only the internet connection is limiting.)

[Perfecthost]

Originally Posted by Xandrios

First of all: I wouldnt quote an email of a client on a public board.

There are two main factors here: Bandwidth and CPU power. Take the max troughtput (100Mbit for example), devide that by the stream bandwidth (i.e. 512Kbit), and you know how many concurent streams the connection can handle.

The CPU part might also be a factor. It depends on how the videos are served. If people can just download them, and a webserver like Lighttpd (www.lighttpd.net) is used, the CPU will be fast enough to utilise hundreds, maybe up to a thousand concurrent connections. If some other tool is used, ie, Real Media server...then you probably need more CPU power. But how much you need....you'll only find out by testing.

But if its just plain serving files: I push 100Mbit with a P4 2.4Ghz using Lighttpd, while server load stays below 0.5. So plain files is no problem at all. (In that case only the internet connection is limiting.)

Thank you for your reply. I would never post critical info of one of my clients. He was informed that I would be asking, also.

I am not a programmer, but he has mentioned that he wants to use Flash for delivering the video.

I have never hosted a server devoted soley to delivering video, so this is a learning experience for me.

[Dennis Nugent]

You have plenty of CPU and RAM for up to 400 mbps of capacity.
Your bottleneck will be the network card / network capacity. If you are on a 100 mbps connection, your bottleneck is around 90 mbps IF your upstream provider can do it
If you are on a GigE connection, your bottleneck will be around 400 mbps, depending on the hard drives and RAID setup

[amps]

What dennis said is true in theory for a LIVE stream.

If he is hosting many files, disk IO can play a big limiting factor. If it's under 500Mb or so of content and you have a couple gigs of RAM, any drive will do. Otherwise you need SCSI.

[Perfecthost]

The server has a 100 mbps connection.

Now, I had already told my client many of the things you all have stated, but he still persists, "How many concurrent streams can we deliver?" He is tired of my "it depends" answers.

I hope you see the issue. I can supply all the info, and give the same answers, but it is very difficult to give a number. I am just trying to get a consensus on a general number. So, throw me out a number, folks!

[Perfecthost]

Oh, the server he is asking about has 7200 rpm drives.

[amps]

RPM of the drive doesn't matter much really. In fact 10k would be ideal if you want to talk RPM =).

The answer to his question depends on his answers to a couple of questions.

1. Size of files

2. Number of files

3. Maximum bitrate of the files

4. Delivery method (apache, windows media services, IIS, ect...)