Maintained by: NLnet Labs

[Unbound-users] Packets lost when multi threading

Leo Baltus
Fri Dec 7 12:20:02 CET 2012


Op 07/12/2012 om 11:50:04 +0100, schreef W.C.A. Wijngaards:
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> Hi Leo,
> 
> On 12/07/2012 11:29 AM, Leo Baltus wrote:
> > Hi,
> > 
> > When I run unbound multi-threaded perf keeps reporting 'Packets
> > lost', but when it runs single threaded it does not.
> > 
> > $ perf -d 10 -a 'www.omroep.nl IN A' 2a02:458:101:31::34 qps:
> > 29262.9 qps: 31986.4 qps: 32167.5 qps: 32479.7 qps: 33064.3 qps:
> > 32174.4 qps: 31408.1 qps: 35887.4 qps: 37471.3 qps: 35364.5 overall
> > time: 	10.0001 sec Packets lost: 	732 0(NOERROR): 	331249 replies 
> > average qps: 	33124.5
> > 
> > This is unbound-1.4.18 with openssl-1.0.0j, ldns-1.6.16 and 
> > libevent-2.0.21-stable running on a linux-2.6.27.59 kernel.
> > 
> > It even reports this when perf is run on the host running unbound.
> > 
> > Is this a known issue?
> 
> No.  Can you try setting so-rcvbuf higher (4m) ?  It may be lost
> simply because it is out of buffers.  There is nothing intrinsic in
> unbound that makes it drop packets in this setup; it must be the OS.
> 

It makes no difference.

here's the multithreading part of my unbound.conf:

        num-threads: 4
        outgoing-range: 8192
        num-queries-per-thread: 4096
        so-rcvbuf: 4m

Also 'netstat -su' does not report any increments on 'receive errors' or
RcvbufErrors.

-- 
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