On Fri, May 9, 2014 at 4:55 AM, Andrew McLean <li...@andros.org.uk> wrote: > Because of latency in the DNS lookup this could > benefit from multithreading.
Before you go too far down roads that are starting to look problematic: A DNS lookup is a UDP packet out and a UDP packet in (ignoring the possibility of TCP queries, which you probably won't be doing here). Maybe it would be easier to implement it as asynchronous networking? I don't know that Python makes it easy for you to construct DNS requests and parse DNS responses; that's something more in Pike's line of work. But it may be more possible to outright do the DNS query asynchronously. TBH I haven't looked into it; but it's another option to consider. Separately from your programming model, though, how are you handling timeouts? Any form of DNS error (NXDOMAIN being the most likely), and the sort-of-error-but-not-error state of getting a response with no answer, indicates that the address is invalid; but what if you just don't hear back from the server? Will that mark addresses off as dead? ChrisA -- https://mail.python.org/mailman/listinfo/python-list
