i am trying to fetch some external data on my PHP site, but having trouble with DNS resolving. When i use curl i get namelookup_time of about 8 seconds. Also tried file_get_contents with same lousy performance. Even gethostbyname takes about 8 seconds to resolve.
I am running php on apache web server, running on CentOS 6.6. My resolv.conf is using google DNS as nameserver, and I don't have any delay when i use dig, hosts, ping or any other DNS related Linux command. Also, if I do curl directly from Linux (or wget), I dont get any delay.
My question is are there any php or apache related dns configuration because i get slow DNS resolve only when using php code, and not when running any linux DNS related command.
UPDATE:
I have made small php script:
<?php
$start = microtime(true);
gethostbyname("google.com");
$end = (microtime(true) - $start);
echo "elapsed time: $end";
?>
to get time of resolve, and when i run it on apache i get
elapsed time: 8.0323350429535
If i run using php from command line i get
elapsed time: 0.025190830230713
so it must be apache related issue.
