When your wordpress blog keep down , not enough connection, while you not expecting that much of traffic, check the web server log see if you can get this, and get a lot of this :
[24/Apr/2016:18:49:01 +0800] “POST /xmlrpc.php HTTP/1.1” 500 585
You may already get attack by xmlrpc.
To disable xmlrpc :
Download and activate plugin , “Disable XMP-RPC” from word press, activate it will disable xml rpc, and issue will solve.
