[help]strange problem about gethostbyname/getaddrinfo

[David DeSimone]

<stutiredboy at gmail.com> wrote:
>
> The problem is we found when the server porcess open 1000+ or higher
> sockets(but we can query any legal domain in the system normally), the
> gethostbyname or getaddrinfo might fetch nothing(sometimes the query
> is ok), the gethostbyname's return error is:  errno=2,strerror=Host
> name lookup failure

It sounds like the resolver library is running into a 1024-descriptor
limit.  From select(2):

NOTES
     The default size of FD_SETSIZE is currently 1024.  In order to accommo-
     date programs which might potentially use a larger number of open files
     with select(), it is possible to increase this size by having the program
     define FD_SETSIZE before the inclusion of any header which includes
     <sys/types.h>.

Unfortunately you might have to rebuild the resolver library itself in
order for it to be able to query file descriptors larger than 1024.

-- 
David DeSimone == Network Admin == fox at verio.net
  "I don't like spinach, and I'm glad I don't, because if I
   liked it I'd eat it, and I just hate it." -- Clarence Darrow


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