just answer the 5 questions:
C.1: [GFS]Specify three most important considerations/rationale behind Google to  design GFS. Also specify what design choices were made to address these in GFS. 
C.2: [GFS]Illustrate through examples what happens if a chunk server goes down in  GFS, i.e., how the self-healing process takes place. 
C.3 [BigTable] Explain Big Table structure through row key, column key with examples. 
C.4 [Big Table] How is bloom filter utilized in Big Table?
C.5 [MR] Describe what happens if a task tracker fails while executing a map task how job tracker detects it and what action it takes.