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