Icecast Streaming Media Server

[trogne]

Hi,

Suppose I have a 300 kbps upload bandwith,

and I broadcast at 50 kbps.

What happen when I reach the max listeners (6) ?

Does the radio starts lagging for everyone?
Or is it just the 7th listeners that will have problems?

Should I set a 'clients' limit in icecast config?


Patrick

[DJ-Zath]

Hi there!

If you have a max listeners limit set in icecast <limits> tag set to 6, then the 7trh listener will receive an "unable to connect, server full" error message (example "ICY 204* - Server full") message while the current listeners will remain not effected.

BUT:

your math isn't entirely correct, I'm afraid.. as if you have 300 Kbps, you'll start to "break up" just after 4 listeners, as this doesn't account for overhead and other network traffic thats also associated with your broadcast and connection handshaking and such..

the basic rule is "no more than 2/3rds your total upload bandwidth" so that means no more than 225 of your total upstream bandwidth can be used for Icecast.

since you're set to 50 Kbps per cast, so @ 225 kbps= 4 listeners max.

I hope this helps!
_________________
-DjZ-

[karlH]

you may get away with 5 listeners, it is getting close and doesn't allow for much with other connections that may be running at the same time.

karl.

[trogne]

OK thanks.

But when there's no 'clients' limit sets,
what is happening when the limit is reached?
Does it affects all the listeners, or only the last one ?


Karl, I don't understand : "doesn't allow for much with other connections that may be running at the same time."

What do you mean?

Patrick

[DJ-Zath]

hi there!

(sorry I didn't see an update here, or I would have replied earlier..)

in the case of this example:

if you exceed the max number of listeners that your bandwidth can support, even by one.. then all the listeners will be effected; this effect can range from latent/missing meta information to complete failure to hold a stream for any said listener(s) Usually, the effect is extreme skipping/tearing of the streams for ALL listeners, making your stream 'un-listenable'.
_________________
-DjZ-

[karlH]

there is always a clients limit, the default is something like 256 and no, I don't know why that figure was decided on originally. If you are getting close to your max throughput then other services could fill in the rest, so web or sql or an FTP transfer could cause streams to stall. As I said 5 is putting it close, less than that should be fine.

karl.

[superfrank]

[superfrank]

[karlH]

if you get the parsinig failure on the xml then the server will terminate and no listeners will get any content. set <max-listeners> in the <mount> for that stream to 5 and you should be fine, setting <clients> to 5 will affect web pages.

karl.

[trogne]

Hi,

What do you mean by 'affect web page' ?

In my config file, I don't set mount tags.

Do you say it is better to replace the <limits><clients>5
with <mount><max-listeners>5
?

[karlH]

clients applies to all requests, so if you request /status.xsl then the browser then starts several connections at the same time for the images, css etc. it won't take many of those to reach the limit if
you set it to 5 or 6. In such cases, it would be better to to set clients higher and set max-listeners in the mount, obviously there will not be many mountpoints in such cases.


karl.

[trogne]

In icecast admin, under 'Global Server Stats', I see the total number of listeners (mount 1 + mount 2).

In icecast config, is it possible to set a max-listeners for the total of all mounts ? (instead of clients, which I see now is clearly not only listeners).

[karlH]

not currently which is why I didn't mention that.

karl.