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

56

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What is a rack awareness algorithm?

70

---

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

58

---

Why rack awareness algorithm is used in hadoop?

53

---

Can you change the block size of hdfs files?

63

---

What is an identity mapper and identity reducer?

668

---

What are the advantages of using mapreduce with hadoop?

642

---

What do you know about nlineinputformat?

746

---

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

720

---

What is the role of recordreader in hadoop mapreduce?

795

---

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

699

---

Define speculative execution?

769

---

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

712

---

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

700

---

What is a map side join?

737

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