What the possible reasons that can cause the Client disconnect?
The possible reasons may be:
1. Idle time out.
2. Server restarts.
3. Network issue.
4. Bug; if it is bug, the error should be reproduced each time.
5. Socket error: like socket cannot write. Just as DBMR1806.
6. User disconnects.
7. Kill connection by DBA or SYSADM.