[Icecast-dev] listen backlog patch

"Thomas B. Rücker" thomas at ruecker.fi
Thu Feb 19 07:18:20 PST 2015


On 02/19/2015 03:07 PM, Stephan Leemburg wrote:
> Hello Icecast-dev,
> I am new to this list.


> I am working for the NPO, the Dutch Public Broadcasting agency.
> We do a lot of icecast streaming. We run at least 20 icecast server
> instances on our media streaming cluster.

That's very nice to hear.

> We ran into an issue that clients which where connecting to our streams
> seemed to be 'hanging' on the connection setup frequently. The client
> 'thinks' it is connected, but no data.
> People suggested that it probably had to do with the poll() call. So, I
> looked into that.
> I found that the issue was actually caused by the very low listen
> backlog (5).
> On our clusters, we typically set this to 8192. Yes it is high, but we
> do a _lot_ of streaming and host very high volume websites.

I'm not very familiar with socket programming, so will let Philipp
comment on this. Interesting enough this issue hasn't come up so far as
far as I can tell and there are some pretty high load deployments out there.

If you can share that info, what sort of concurrent listener load are we
talking about?

> Currently we are using icecast 2.3. We are migrating to 2.4.
> So, I have written patches for 2.3 and 2.4, but also for the current 2.5
> git tree.
> Unfortunately, I am a newby when it comes to git (sorry). But I do have
> unified diff patch files for the 2.3, 2.4 and 2.5 source trees.
> The patched 2.4 icecast was tested by our media streaming team and they
> confirmed that their issue was solved by it.
> Can I submit them (and how)?

Just send them as attachments to this list, or open a ticket over at
If trac is naughty and thinks you're a spammer, please let me know.

If there are differences between them, then please the 2.5 and 2.4
patches. Otherwise 2.5 will do just fine.

Thanks a lot for taking the time to reach out to us!



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