Process 0x0xdaf25e08 appears to be hung in Auto SQL Tuning task

Hello

        I got message in the alert log like this(below).It appears almost at the same time everyday.

        From ASH, I can see the session start at 22:00. No event info.

        What's the reason about this question ?

      

       Version Oracle11gR2  11.2.0.4.7

  

ALert: 

Mon Oct 09 23:10:59 2017

Process 0x0xdaf25e08 appears to be hung in Auto SQL Tuning task

Current time = 1507561858, process death time = 1507561801

Attempting to kill process 0x0xdaf25e08 with OS pid = 17147

OSD kill succeeded for process 0xdaf25e08

Tue Oct 10 23:10:12 2017

Process 0x0xdaf25e08 appears to be hung in Auto SQL Tuning task

Current time = 1507648211, process death time = 1507648202

Attempting to kill process 0x0xdaf25e08 with OS pid = 14899