Cloud-Computing-Concepts-Part-2

Coursera course : https://www.coursera.org/specializations/cloud-computing

What is the project?

• Building a Fault-Tolerant Key-Value Store.

• The main functionalities of the Key-Value Store :

  • CRUD operations : A key-value store supporting CRUD operations (Create, Read, Update, Delete).
  • Load-balancing : via a consistent hashing ring to hash both servers and keys.
  • Fault-tolerance up to two failures : by replicating each key three times to three successive nodes in the ring, starting from the first node at or to the clockwise of the hashed key.
  • Quorum consistency level for both reads and writes (at least two replicas).
  • Stabilization : after failure (recreate three replicas after failure).

Principle of Fault-Tolerant Key-Value Store :

How do I run the Grader on my computer ?

• There is a grader script KVStoreGrader.sh. The tests include:
  • Basic CRUD tests that test if three replicas respond
  • Single failure followed immediately by operations which should succeed (as quorum can still be reached with 1 failure)
  • Multiple failures followed immediately by operations which should fail as quorum cannot be reached
  • Failures followed by a time for the system to re-stabilize, followed by operations that should succeed because the key has been re-replicated again at three nodes.

	$ chmod +x KVStoreGrader.sh
	$ ./KVStoreGrader.sh

Result

• Points achieved: 90 out of 90 [100%]