#48 Failed DNS lookups cause long freezes

Engine (43)

DNS lookups that time out cause ZNC to do nothing during the attempted lookup, this leads to 30+ second freezes if the DNS server for the domain is down.

This was observed on FreeBSD 7.0-RELEASE, I have not tested other platforms.

Xaquseg - IRCHighWay, server co-admin of avalon.*


  • Psychon

    Psychon - 2009-01-07

    I can confirm that ZNC does blocking DNS, however you have more serious problems than short lockops in this case.
    Some quick got a 10 and a 15 sec timeout on linux and a 18 second timeout on a freebsd box for an unreachable DNS server, so I don't know why yours is soo high.
    Anyway, while it may be annoying, these freezes shouldnt cause too much trouble, so they are not a top priority so far. Still we are working on a fix.

  • Psychon

    Psychon - 2009-01-07
    • priority: 5 --> 4
    • assigned_to: prozacx --> nobody
  • Psychon

    Psychon - 2009-08-03
    • status: open --> closed
  • Psychon

    Psychon - 2009-08-03

    Starting with 0.052 ZNC can use c-ares which fixes this.


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