Hello,
as some noticed and informed privately or on mailing list, several
days ago kamailio.org was not accessible.
It was caused by apache getting stuck on connecting to a remote host
due to the pingback feature of wordpress. All the other services
were fine. Listing running processes showed a large number of apache
instances connecting to an address like 23.x.y.204 and being stuck
in that state.
Fetching the page from that address with wget resulted in some html
with embedded obfuscated javascript. I couldn't find a reason why
apache was not closing the connection, although there are some
timeouts in configs. Also, as I expect apache/php/wordpress don't
run javascript, the issue should be somewhere at the http layer. At
some point apache reached the max number of threads and didn't serve
other requests.
The solution was to disable the pingbacks using a plugin for
wordpress named: Disable XML-RPC Pingback . All seems ok for the
last days.
I posted here just in case it will be useful for someone else, but
also to get hints on other tweaks that we should to do wordpress to
prevent similar situation, if anyone can share from his/her
experience.
Cheers,
Daniel
--
Daniel-Constantin Mierla
http://twitter.com/#!/miconda - http://www.linkedin.com/in/miconda
Kamailio World Conference, May 27-29, 2015
Berlin, Germany - http://www.kamailioworld.com