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When I download any document from internet using wget. It shows maximum amount of time consumed in getaddrinfo().

I know getaddrinfo() used for DNS lookup.

Tell me any method, so that this time is reduced to negligible, just like making any table for host name and their corresponding IP address, so that wget can get coresponding IP address very quickly.

Question

Tell me also, how can I implement this. Thanks in advance. Looking for your kind response.

Command, I use

ltrace -c -o log_ltrace_wget_new1.txt wget http://www.ada.gov/briefs/kovacsbr.doc

Output

% time     seconds  usecs/call     calls      function
------ ----------- ----------- --------- --------------------
 67.11    7.070607      336695        21    select
 19.67    2.071956        5739       361    strlen
 10.59    1.115199     1115199         1    getaddrinfo
  0.32    0.033705         298       113    fgets
  0.27    0.028261         197       143    malloc
  .....
  .....
  .....
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2  
Possibly it's trying to do a AAAA query to resolve IPv6 addresses and that timesout or something along those lines. Try a network capture to get a better idea of what's causing the delay. – Stephane Chazelas Mar 12 at 7:56

1 Answer

up vote 2 down vote

Build a local dns cache using nscd (Name service cache daemon) or dnsmasq (A real dns server)

Otherwise alternate your default dns server from /etc/resolv.conf

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I added IP address of www.ada.gov, i.e., 149.101.146.61 in resolv.conf. [In vi editor, it shows this line in red background] .But it shows the same time consumed in getaddrinfo. – devsda Mar 12 at 7:00
@jhamb then there's no way to improve it unless you give up glibc – warl0ck Mar 12 at 7:05
But there is no change shown in time consumed in getaddrinfo(). If I resolve DNS locally, then it should show less time than previous. Why it does not show less time ? – devsda Mar 12 at 7:07
Note that at least on Debian and Ubuntu, host caching is disabled in the default configuration, so you need to reenable it. – Stephane Chazelas Mar 12 at 7:48
2  
@jhamb jftr if you added www.ada.gov to resolv.conf nothing will change as it is the wrong configuration file. Either try to use another dns server like 8.8.8 or add www.ada.gov to /etc/hosts or follow stephanes advice – Ulrich Dangel Mar 12 at 8:01
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