Yesterday (4/1/2013), I discovered that I was completely unable to access the Dolphin admin of my site which is running 7.1.1. I was able to log INTO the page (which loaded), but once I was in, my browser (Google Chrome) locked up to page requests, and I was unable to load anything at all from my website without completely closing the browser and re-opening. A few quick tests verified that this also occurred in IE and Firefox.
Remembering past experiences, I quickly checked to see if Boonex.com was online and a double check via the isup.me website confirmed that the site was offline. (At least in my part of the world)
Remembering something I read on the forums a few days back, I disabled the links in the $aPredefinedRssFeeds array in get_rss_feed.php, and was able to access my site again.
I had run into something similar to this when I tried to upgrade my site from 7.0.6 to 7.0.9, only that problem had been: if the forum feed was placed on the main home page, the browser locked up tight as a drum and wouldn't respond. My temporary solution to that was to disable the cURL routines in the bx_file_get_contents() function in /inc/utility.inc.php, and to let everything be retrieved through the php file_get_contents() function. However, it now seems that that wasn't fixing things in this scenario.
Having grown tired of both problems, and wanting to make as few changes to core Dolphin code as possible, I re-enabled the cURL routines so that they were back to the Dolphin standard, and then began tinkering with them.
To limit the problem that occurs when Dolphin tries to "phone home" in the admin, (to get RSS info about current blogs, modules, etc), I added a timeout of 10 seconds to the cURL connection. This way, even if the Boonex site is down, my browser won't sit forever waiting. I was then able to re-enable the Boonex links, and only suffer a minor delay of 10 seconds whenever a page tried to load something.
The second problem (the one that made me disable the cURL routines in the first place) was more troubling. I tested everything I could think of, and ruled out a cURL misconfiguration on the server (cURL could pull the page via shell, so it wasn't that) and then began scouring the internet. Finally, I ran across this page: http://stackoverflow.com/questions/5412069/can-i-do-a-curl-request-to-the-same-server
It turns out, if you have your server configured to auto-start PHP sessions, OR have either made modifications to your skin or code that uses PHP sessions, that PHP places a lock on the session while the script is running. If the script THEN tried to access another script on the same server which ALSO tries to access the session, then the 2nd script can't access the session because of the lock from the calling script, so waits patiently for the script to end. (whew) This causes the two scripts to wait patiently until the PHP page timeout occurs, at which point the scripts end, and the page never loads.
Thankfully, the same article provided a solution which I am posting here:
in the bx_file_get_contents() function in /inc/util.inc.php (around line 1161), change the code:
$sResult = curl_exec($rConnect);
to:
curl_setopt($rConnect, CURLOPT_TIMEOUT, 10);
session_write_close();
$sResult = curl_exec($rConnect);
session_start();
