Strange issues with XML / RSS Feeds on Centos 5.5

bzzik · 11-02-2010, 03:13 AM

Good day to all.

Some days ago I have upgrade my server and installed Centos 5.5 x64 using this tutorial (before that I was using Slackware i386, PHP 5.2.6). Also I updated PHP to latest 5.3.3.

But I faced strange issue with XML / RSS Feeds (may be it is not related to XML directly, but it is one of the discovered issues) on my sites. XML requests are working very slow and any of RSS feeds are not working now. I thought that it is PHP issue and downgraded to 5.2.14. But the problem still exists

I was trying to change Apache config, also changed php.ini, but nothing helps

On previous server installation everything worked fine...

Update: downgrading to PHP 5.2.6 also did not help.

Here is my current PHP info.
Here is the site where xml queries working very slow (notice server data queries).

Any advice will be helpful.

Thank you.

bzzik · 11-08-2010, 03:22 AM

So, after debugging one of the PHP scripts, I found out that the problem is in cURL. Name lookup is slow in it. Sometimes it took less that 1 second to lookup, but sometimes up to 10 seconds. If I try to lookup local server, it is always less than 1 second. If it is lookup of ours other web server (which is in LAN) - sometimes less than 1 second and sometimes up to 5 seconds.

Here are curl_getinfo() dumps

Local server

Quote:

array(20) { ["url"]=> string(19) "http://s1.contra.lv" ["content_type"]=> string(24) "text/html; charset=utf-8" ["http_code"]=> int(200) ["header_size"]=> int(761) ["request_size"]=> int(51) ["filetime"]=> int(-1) ["ssl_verify_result"]=> int(0) ["redirect_count"]=> int(0) ["total_time"]=> float(0.59913) ["namelookup_time"]=> float(2.5E-5) ["connect_time"]=> float(7.6E-5) ["pretransfer_time"]=> float(7.8E-5) ["size_upload"]=> float(0) ["size_download"]=> float(104746) ["speed_download"]=> float(174830) ["speed_upload"]=> float(0) ["download_content_length"]=> float(-1) ["upload_content_length"]=> float(0) ["starttransfer_time"]=> float(0.583356) ["redirect_time"]=> float(0) }

Took 0.59913 seconds to send a request to http://s1.contra.lv

Second web server in LAN

Quote:

array(20) { ["url"]=> string(19) "http://s2.contra.lv" ["content_type"]=> string(24) "text/html; charset=UTF-8" ["http_code"]=> int(200) ["header_size"]=> int(265) ["request_size"]=> int(51) ["filetime"]=> int(-1) ["ssl_verify_result"]=> int(0) ["redirect_count"]=> int(0) ["total_time"]=> float(5.002668) ["namelookup_time"]=> float(5.001231) ["connect_time"]=> float(5.001649) ["pretransfer_time"]=> float(5.001652) ["size_upload"]=> float(0) ["size_download"]=> float(1207) ["speed_download"]=> float(241) ["speed_upload"]=> float(0) ["download_content_length"]=> float(1207) ["upload_content_length"]=> float(0) ["starttransfer_time"]=> float(5.002648) ["redirect_time"]=> float(0) }

Took 5.002668 seconds to send a request to http://s2.contra.lv

Quote:

array(20) { ["url"]=> string(19) "http://s2.contra.lv" ["content_type"]=> string(24) "text/html; charset=UTF-8" ["http_code"]=> int(200) ["header_size"]=> int(265) ["request_size"]=> int(51) ["filetime"]=> int(-1) ["ssl_verify_result"]=> int(0) ["redirect_count"]=> int(0) ["total_time"]=> float(0.003021) ["namelookup_time"]=> float(0.001471) ["connect_time"]=> float(0.001959) ["pretransfer_time"]=> float(0.001961) ["size_upload"]=> float(0) ["size_download"]=> float(1207) ["speed_download"]=> float(399536) ["speed_upload"]=> float(0) ["download_content_length"]=> float(1207) ["upload_content_length"]=> float(0) ["starttransfer_time"]=> float(0.003006) ["redirect_time"]=> float(0) }

Took 0.003021 seconds to send a request to http://s2.contra.lv

Remote host

Quote:

array(20) { ["url"]=> string(42) "http://feeds.joomla.org/JoomlaSecurityNews" ["content_type"]=> string(23) "text/xml; charset=UTF-8" ["http_code"]=> int(200) ["header_size"]=> int(358) ["request_size"]=> int(73) ["filetime"]=> int(-1) ["ssl_verify_result"]=> int(0) ["redirect_count"]=> int(0) ["total_time"]=> float(0.270293) ["namelookup_time"]=> float(0.002906) ["connect_time"]=> float(0.061371) ["pretransfer_time"]=> float(0.061374) ["size_upload"]=> float(0) ["size_download"]=> float(21219) ["speed_download"]=> float(78503) ["speed_upload"]=> float(0) ["download_content_length"]=> float(-1) ["upload_content_length"]=> float(0) ["starttransfer_time"]=> float(0.149823) ["redirect_time"]=> float(0) }

Took 0.270293 seconds to send a request to http://feeds.joomla.org/JoomlaSecurityNews

Quote:

array(20) { ["url"]=> string(42) "http://feeds.joomla.org/JoomlaSecurityNews" ["content_type"]=> string(23) "text/xml; charset=UTF-8" ["http_code"]=> int(200) ["header_size"]=> int(358) ["request_size"]=> int(73) ["filetime"]=> int(-1) ["ssl_verify_result"]=> int(0) ["redirect_count"]=> int(0) ["total_time"]=> float(10.272009) ["namelookup_time"]=> float(10.003368) ["connect_time"]=> float(10.057596) ["pretransfer_time"]=> float(10.0576) ["size_upload"]=> float(0) ["size_download"]=> float(21219) ["speed_download"]=> float(2065) ["speed_upload"]=> float(0) ["download_content_length"]=> float(-1) ["upload_content_length"]=> float(0) ["starttransfer_time"]=> float(10.160526) ["redirect_time"]=> float(0) }

Took 10.272009 seconds to send a request to http://feeds.joomla.org/JoomlaSecurityNews

So may be the problem not in cURL, but I have an incorrect server configuration. Some problem in resolving? I checked resolv.conf and there are correct nameservers. I compared setting with second web server and they are seems to be fine.

P.S.
Please note, that everything is fine on my second web server. Such problem is only on this server.

Update:
The problem is solved. In resolv.conf were incorrect nameservers (from another ISP). Changed them and after sometime everything started to working fine. Hope, this helped.