[nsd-users] nsd utilize 100% cpu

Vadim vvatlin at yandex.ru
Fri Dec 11 15:52:53 UTC 2009

Paul Wouters wrote:
> On Thu, 10 Dec 2009, Vadim wrote:
>>> Apparently nsd writes each domain label separately, without any attempt
>>> to batch writes.  It's much better than writing by single char as some
>>> other programs are doing but worse still than batching writes in at 
>>> least
>>> 512byte blocks like stdio is doing.
>>>> And even after 20 minutes after "nsd patch" have finished, nsd 
>>>> process still use 100% cpu.
>>> How long it takes total? 
>> I ran again nsdc patch and nsd utilized  100% cpu about 10 minutes
> You mean nsdc rebuild? I wouldn't expect nsd patch to take that long. 
> Though
> AFAIK, nsd patch should not affect the nameserver operations going on.
No. I mean nsdc patch. I don't know what nsd do at this time, because 
command nsd patch works:
time nsdc patch > /dev/null 2>&1

real    0m43.057s
user    0m15.181s
sys     0m1.404s

But after that, nsd process begin utilize 100% cpu for a long time. I 
showed strace above.

Look what I see in top:

26044 nsd       25   0  204m 193m  356 R 99.9    37.8     32:05.96 

for 20 minutes now. Also I have upgraded nsd to 3.2.3 version but I see 
the same behaviour.

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