Re^3: Apache or Daemon in Perl ?

I'm curious ... Let's say, using UDP, message 1 comes in, then message 3, then message 5, and then message 2, and message 4 got dropped. How would you check ordering here? You process 1 immediately, but wait for a few messages to come in, then get message 2, process 2 and 3, and then ... when do you process 5? Or would you be proposing that with UDP, you would only process the messages that already came back in order, dropping all that were delayed out of order?

Comment on Re^3: Apache or Daemon in Perl ?

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Re^4: Apache or Daemon in Perl ? by hardburn (Abbot) on Jan 18, 2005 at 16:04 UTC
There are many ways to do this. Some protocols treat UDP like AOL CDs--it doesn't matter if the post office forgets to to deliver the one you got today, because you'll get another one tommarow. A good example protocol where it does matter is TFTP (RFC 1350) (which is very different from regular FTP). It solves it with a challenge-response mechanism. The sender sends packet 1, and the receiver acks it. Then the sender sends packet 2, and so on. If a packet is lost or comes out of order, the sender is expected to resend after a timeout. "There is no shame in being self-taught, only in not trying to learn in the first place." -- Atrus, Myst: The Book of D'ni.	[reply]
Re^4: Apache or Daemon in Perl ? by Mutant (Priest) on Jan 18, 2005 at 16:46 UTC
The idea of UDP is that you implement whatever achitecture you want to deal with whatever your specific situation is (the U is for User :)	[reply]
Re^4: Apache or Daemon in Perl ? by jimrobertsiii (Scribe) on Jan 19, 2005 at 05:58 UTC
In the past we have added a "sequenceid" to the header and dropped any packets that were out of sequence. -Jim	[reply]