Hello Alwina,
I am sorry, but not exactly sure about how to check and obtain the answers to your questions.
Here is the exact alert:
Alert Details
Name....................ABAP Instance not available
Start Time..............17.03.2015 20:13:12 CET
End Time................17.03.2015 20:13:12 CET
Managed Object..........<SID>~ABAP~<SID>_<SID>_10
Managed Object Type.....Technical Instance
Rating..................Yellow
Category................Availability
Status..................Open
Alert Description
The ABAP instance <SID>_<SID>_10 or parts of it are not running. Please check the alert details to see which components do not respond. Restart the instance if necessary.
Analysis Tools:
View instance status in SAP Management Console.
Manually check the Http availability of the instance.
Try to log on to the instance:
Alert Data
Link to Alert Details
Link to Alert Inbox