What is the difference between nas (network attached storage) and hdfs?

50

---

What is a rack awareness algorithm?

58

---

What is the problem in having lots of small files in hdfs?

46

---

Why rack awareness algorithm is used in hadoop?

41

---

Can you change the block size of hdfs files?

45

---

What is an identity mapper and identity reducer?

600

---

What are the advantages of using mapreduce with hadoop?

588

---

What do you know about nlineinputformat?

679

---

Why the output of map tasks are stored (spilled ) into local disc and not in hdfs?

660

---

What is the role of recordreader in hadoop mapreduce?

728

---

What happens when the node running the map task fails before the map output has been sent to the reducer?

646

---

Define speculative execution?

711

---

Is it legal to set the number of reducer task to zero? Where the output will be stored in this case?

658

---

What are the advantages of using map side join in mapreduce?

644

---

What is a map side join?

683

---