Scalability refers to the ability to expand cloud facilities and services on demand to meet user needs, beyond any limits. Fault tolerance is the ability to tolerate mistakes made by users. Developing cloud systems that can scale highly and tolerate failures is challenging for cloud providers, as they must manage huge numbers of resources and users while providing competitive performance even as failures occur normally.

1. Scalability and FaultToleranceScalability and FaultTolerance
What is This??????
It is the ability to scale on-demand the facilities and
services as and when they are required by the user.
Fault Tolerance is nothing, it is just Tolerating the
faults that are done by mistake by the user.
Here the scaling is beyond the limits, it means we
even can’t imagine what will be the limit.
cloud middleware is designed on the principle of
scalability along different dimensions in mind e.g.:-
performance, size and load.

2. Scalability and Fault ToleranceScalability and Fault Tolerance
The cloud middleware manages a huge number of
resources and users which depends on the cloud to obtain
that they can’t obtain within the premises without affording
the administrative and maintenance costs.
So in this overall scenario the ability to tolerate the failure
is normal but sometimes it becomes important than
providing an efficient & optimized system.
The overall conclusion says that “it is a challenging task for
the cloud providers to develop such high scalable and fault
tolerance systems who can get managed and at the same
time they will provide a competitive performance.