The analytics code has been wrapped in a try-catch block since 2 November 2014, so it definitely shouldn't be the problem (unless it doesn't work as intended?); if estabilishing a connection to the analytics server fails for whatever reason, it should log an error message to the log (/var/log/hhvm/error.log) but continue deleting whatever it can. Grepping this error log file currently yields 14 matches, 13 of them being "Can't connect to MySQL server on <IP address>" and the odd one out being "Unknown database 'analytics'" (wtf).

Further grepping the same file for "DeleteWiki" yields lots and lots of "permission denied" errors as well as these, which I believe are essentially "permission denied" errors in disguise:

Warning: unlink(/var/www/live/w/images/lumini/): No such file or directory in /var/www/live/w/extensions/CreateWiki/DeleteWiki_body.php on line 298
Warning: readdir() expects parameter 1 to be resource, boolean given in /var/www/live/w/extensions/CreateWiki/DeleteWiki_body.php on line 291

cc'ing @lewiscawte for further thoughts on this.

So without looking into it further, I seem to recall previous investigation of similar errors resulting in the conclusion that these files didn't exist, and therefore was failing as expected although a mental note was filed that better error handling was needed.

In addition to that, it might be worth checking that DeleteWiki doesn't have hardcoded paths (T40) as those are creating problems in other places (T41).