Which of the following is primarily used to provide fault tolerance at the application level? (Select
TWO)
A.
Load balancing
B.
RAID array
C.
RAID 6
D.
Server clustering
E.
JBOD array
Get 50% Discount on All Your Purchases
at PrepAway.com - Latest Exam Questions
This is ONE TIME OFFER
50%
I agree with server clustering, but RAID array includes RAID 0 which has no redundancy (fault tolerance) so I think the second choice should be RAID 6 which can overcome hardware failure.
0
0
You make a good point. A RAID array is usually fault tolerant, but RAID 6 is always fault tolerant.
0
0
RAID6 is not at application layer….answer is A and D
1
0
I agree. Raid is both hardware and software but load balancing and clustering is at application level
2
0
As it is with such questions, I always look for the key words and concepts.
We are clearly after FAULT TOLERANCE in here. Apart from JBOD, all the answers deal with that one way or another. Yet, we are after fault tolerance at the APPLICATION LEVEL (the Application layer of the OSI model.)
Dealing with the remaining concepts.
RAID. Redundant Array of Independent Disks, is a data storage virtualization technology that combines multiple physical disk drive components into one or more logical units for the purposes of data redundancy, performance improvement, or both.
Clustering v Load Balancing .What is the difference.
These 2 terms are used in the same sense by a majority of IT people with relative impunity.
Clustering has a formal meaning. A cluster is a group of resources that are trying to achieve a common objective, and are AWARE of one another. Clustering usually involves setting up the resources (servers usually) to exchange details on a particular channel (port) and keep exchanging their states, so a resources state is replicated at other places as well. It usually also includes load balancing, wherein, the request is routed to one of the resources in the cluster as per the load balancing policy. So LOAD BALANCING is an integral part of CLUSTERING.
Load balancing can also happen without clustering when we have multiple independent servers that have same setup, but other than that, are UNAWARE of each other. Then, we can use a load balancer to forward requests to either one server or other, but one server does not use the other servers resources. Also, one resource does not share its state with other resources. Load balance deals more with PERFORMANCE, rather than with REDUNDANCY
So to my mind, in order to provide redundancy at the Application layer of the OSI model we need
B.RAID ARRAY
D.Server Clustering
1
0