Study tips AWS-SysOps

Which of the below AWS tool will help for this requirement?

What will happen to the instances?

Which of the below mentioned event categories is not supported by RDS for this snapshot source type?

Which of the below mentioned steps are not required while using Cloudformation?

Which of the below mentioned statements is not true with respect to the estimated charges?

how will AWS ensure that a switch from DB to a standby replica will not affect access to the application?

which is the best possible solution?

how many instance hours will AWS charge the user?

How can the user track the calls made to CloudWatch?

what will happen?