nscd and DNS cache

[Ed Greshko]

On 05/18/2012 05:21 PM, JD wrote:
> That value is good for comparison only as it is not
> the real time. Take a look at this:
>
> time dig @8.8.8.8 www.ny.com
>
> ; <<>> DiG 9.8.2-RedHat-9.8.2-1.fc16 <<>> @8.8.8.8 www.ny.com
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24466
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;www.ny.com.            IN    A
>
> ;; ANSWER SECTION:
> www.ny.com.        3383    IN    CNAME    web1.ny.com.
> web1.ny.com.        3383    IN    A    184.106.212.108
>
> ;; Query time: 61 msec
> ;; SERVER: 8.8.8.8#53(8.8.8.8)
> ;; WHEN: Fri May 18 03:17:11 2012
> ;; MSG SIZE  rcvd: 63
>
>
> real    0m10.07s
> user    0m0.01s
> sys    0m0.01s
>
> So, the router or my super lightly loaded laptop,
> or the ISP, must be the cause of such delays.
>
> $  w
>  03:20:45 up  5:52,  3 users,  load average: 0.02, 0.02, 0.05 

Something must be really strange on your system.....

The same time dig command on my system(s) yield....

;; Query time: 21 msec

real    0m0.029s
user    0m0.002s
sys     0m0.005s

Your query time is 61 msec which sounds reasonable.  So, dig sent out and got back
the response quite fast...and user and sys times seem reasonable...without knowing
your hardware. 

I can't see how your router or ISP could add to the "real" time.  I suppose you don't
have another system to check it....


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