Atlas with latest bits is not responding for any query, the request times out. This behavior can be seen for more than ~15 minutes after atlas startup and everything will be back to normal after this period.
I suspect one of the threads is looping or hanging which is resulting in this state. Atlas logs does not show any suspicious information (checked with debug logs as well). I took a thread dump of Atlas, attaching the dump file and report below. I strongly suspect, this might be an issue with newer jetty version introduced recently.