wget has a default read timeout of 900 seconds
according to the manpage. What I think happens is the first
one takes 15 minutes to timeout and restart the server.
then the other 3 which have been trying to read as well
then get fails immediately when the server is restarted
which gives you the next 3 restarts.
adding --timeout=20 to the wget might fix it (it's worth a try anyway). I suspect if the server is taking more than 20 seconds to serve the dbtest page its probably in a sick state.
