Re^4: UDP server with IO::Socket::INET

the server could remove them when the send fails

That won't work. The send won't fail if the receiver stops receiving. You need some explicit disconnection mechanism.

send doesn't wait for the datagram to be sent and acknowledged, so at best you'd know if a past send failed.
There's no connection to keep track of a past send failures.
There's no acknowledgment sent by the remote end to say it didn't fail.

The send will only fail if there's a local error (e.g. bad argument, no more resources, etc)

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Re^5: UDP server with IO::Socket::INET by rowdog (Curate) on Mar 04, 2010 at 11:24 UTC
If this was my project, I would definitely use an explicit disconnection. That said, ICMP does provide "Destination Unreachable" which could be used to detect clients that are MIA. Of course, using ICMP for this would be a lot of work for very little practical gain, which is why I recommended multicast.	[reply]
Re^6: UDP server with IO::Socket::INET by ikegami (Patriarch) on Mar 04, 2010 at 19:37 UTC
which is why I recommended multicast. Are you saying that multicast drops unreachable machines automatically?	[reply]
Re^7: UDP server with IO::Socket::INET by rowdog (Curate) on Mar 05, 2010 at 12:54 UTC
No, I'm saying that it is possible to detect missing clients with ICMP but a much better alternative would be an existing ~~explicit connection~~ protocol, such as multicast. Update: I realized too late that multicast doesn't actually use explicit connections but that's part of the beauty of multicast.	[reply]
Re^8: UDP server with IO::Socket::INET by ikegami (Patriarch) on Mar 05, 2010 at 16:30 UTC
Re^9: UDP server with IO::Socket::INET by rowdog (Curate) on Mar 06, 2010 at 17:39 UTC
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