Maintained by: NLnet Labs

Unbound exiting on stats write failure?,Re: Unbound exiting on stats write failure?

Havard Eidnes
Mon Oct 3 14:12:57 CEST 2016

>> one of our unbound hosts recently exited, and before it did, it
>> logged this:
>>   Sep 19 14:25:56 xxxxxxx unbound: [96:4] error: tube msg write failed: Resource temporarily unavailable
>>   Sep 19 14:25:56 xxxxxxx unbound: [96:4] fatal error: could not write stat values over cmd channel
> The error is on a pipe between unbound processes (threads).  It should
> not be out of resources (it might block of course, waiting for them, and
> blocking pipes are not a problem for unbound, but this error is like a
> pipe randomly breaks up).

This turned out to be caused by us running a too old version of
unbound, version 1.5.4.  I've since upgraded to 1.5.9, so this
exact problem should not happen again for us.  In-between there,
tube_write_msg() grew a test for EAGAIN (causing a retry) in the
non-blocking case.


- Håvard