Cluster planning and sizing in Hadoop - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to specify the number of nodes in the Hadoop cluster.

Hadoop

num_nodes = [1]

Drag options to blanks, or click blank then click option'

Acluster_size

B10

Cnode_count

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name instead of a number.

Choosing a number too large for a small cluster.

The number of nodes is set to 5 to define the cluster size.

2fill in blank

medium

Complete the code to calculate total storage capacity in TB.

Hadoop

total_storage_tb = num_nodes * [1]

Drag options to blanks, or click blank then click option'

A500

B100

C2

D1024

Attempts:

3 left

💡 Hint

Common Mistakes

Using storage size in GB instead of TB.

Multiplying by an incorrect storage value.

Each node has 2 TB storage, so total storage is nodes times 2.

3fill in blank

hard

Fix the error in the code to calculate total memory in GB.

Hadoop

total_memory_gb = num_nodes [1] 64

Drag options to blanks, or click blank then click option'

A*

B-

C+

D/

Attempts:

3 left

💡 Hint

Common Mistakes

Using addition instead of multiplication.

Using division which gives wrong results.

Total memory is number of nodes multiplied by memory per node (64 GB).

4fill in blank

hard

Fill both blanks to create a dictionary of node memory and storage.

Hadoop

node_specs = {'memory_gb': [1], 'storage_tb': [2]

Drag options to blanks, or click blank then click option'

A64

B128

C2

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing memory and storage values.

Using total cluster values instead of per node.

Each node has 64 GB memory and 2 TB storage.

5fill in blank

hard

Fill all three blanks to create a summary dictionary with nodes, total memory, and total storage.

Hadoop

cluster_summary = {'nodes': [1], 'total_memory_gb': [2], 'total_storage_tb': [3]

Drag options to blanks, or click blank then click option'

A5

B320

C10

D64

Attempts:

3 left

💡 Hint

Common Mistakes

Using per node values instead of totals.

Mixing up memory and storage values.

The cluster has 5 nodes, total memory is 5*64=320 GB, and total storage is 5*2=10 TB.

Practice

1. What is the main goal of cluster planning in Hadoop?

easy

A. To increase network speed only

B. To write complex MapReduce code

C. To ensure enough resources for big data tasks

D. To reduce the size of data stored

Solution

1. Step 1: Understand cluster planning purpose

   Cluster planning is about preparing resources like CPU, memory, and storage to handle big data jobs efficiently.

2. Step 2: Identify the main goal

   The main goal is to ensure the cluster has enough resources to process and store data reliably.

3. Final Answer:

   To ensure enough resources for big data tasks -> Option C

4. Quick Check:

   Cluster planning = resource readiness [OK]

Hint: Think about what cluster planning prepares for [OK]

Common Mistakes:

• Confusing cluster planning with coding tasks
• Thinking it only improves network speed
• Assuming it reduces data size

2. Which of the following is the correct way to calculate total storage needed for a Hadoop cluster with 10 TB data and replication factor 3?

easy

A. 10 TB * 3 = 30 TB

B. 10 TB / 3 = 3.33 TB

C. 10 TB + 3 = 13 TB

D. 10 TB - 3 = 7 TB

Solution

1. Step 1: Understand replication factor meaning

   Replication factor 3 means each data block is stored 3 times for fault tolerance.

2. Step 2: Calculate total storage

   Total storage = original data size * replication factor = 10 TB * 3 = 30 TB.

3. Final Answer:

   10 TB * 3 = 30 TB -> Option A

4. Quick Check:

   Storage needed = data size x replication factor [OK]

Hint: Multiply data size by replication factor [OK]

Common Mistakes:

• Dividing instead of multiplying
• Adding or subtracting replication factor incorrectly
• Ignoring replication factor

3. Given a Hadoop cluster with 5 nodes, each having 16 CPU cores and 64 GB RAM, what is the total CPU cores and RAM available?

medium

A. 80 CPU cores and 320 GB RAM

B. 16 CPU cores and 64 GB RAM

C. 5 CPU cores and 5 GB RAM

D. 320 CPU cores and 80 GB RAM

Solution

1. Step 1: Calculate total CPU cores

   Total CPU cores = number of nodes * CPU cores per node = 5 * 16 = 80 cores.

2. Step 2: Calculate total RAM

   Total RAM = number of nodes * RAM per node = 5 * 64 GB = 320 GB.

3. Final Answer:

   80 CPU cores and 320 GB RAM -> Option A

4. Quick Check:

   Total CPU = 5x16, Total RAM = 5x64 [OK]

Hint: Multiply nodes by cores and RAM per node [OK]

Common Mistakes:

• Adding CPU cores and RAM instead of multiplying
• Mixing CPU cores with RAM units
• Using per node values as total

4. Identify the error in this cluster sizing calculation: A cluster has 8 nodes, each with 32 GB RAM. The total RAM is calculated as 8 + 32 = 40 GB. What is wrong?

medium

A. Ignoring CPU cores

B. Multiplying nodes and RAM correctly

C. Using wrong units for RAM

D. Adding nodes and RAM instead of multiplying

Solution

1. Step 1: Understand total RAM calculation

   Total RAM should be number of nodes multiplied by RAM per node, not added.

2. Step 2: Identify the mistake

   The calculation 8 + 32 = 40 GB is incorrect; it should be 8 * 32 = 256 GB.

3. Final Answer:

   Adding nodes and RAM instead of multiplying -> Option D

4. Quick Check:

   Total RAM = nodes x RAM per node [OK]

Hint: Multiply nodes by RAM, don't add [OK]

Common Mistakes:

• Adding node count and RAM size
• Confusing units of measurement
• Ignoring multiplication for totals

5. You have 20 TB of raw data with replication factor 3 and want to plan a Hadoop cluster. Each node has 4 TB usable storage. How many nodes are needed at minimum to store the data?

hard

A. 20 nodes

B. 15 nodes

C. 60 nodes

D. 5 nodes

Solution

1. Step 1: Calculate total storage needed with replication

   Total storage = raw data x replication factor = 20 TB x 3 = 60 TB.

2. Step 2: Calculate number of nodes needed

   Nodes needed = total storage / storage per node = 60 TB / 4 TB = 15 nodes.

3. Final Answer:

   15 nodes -> Option B

4. Quick Check:

   Nodes = (data x replication) ÷ node storage [OK]

Hint: Divide total replicated data by node storage [OK]

Common Mistakes:

• Ignoring replication factor
• Dividing raw data by node storage only
• Rounding nodes incorrectly