Container allocation in Hadoop - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Container Allocation in Hadoop YARN

Which statement best describes the role of container allocation in Hadoop YARN?

A Containers are the physical machines where Hadoop daemons run.

B Containers store the data blocks in HDFS for distributed storage.

C Containers are used to manage network traffic between Hadoop nodes.

D Containers are allocated by the ResourceManager to run application tasks with specific resource requirements.

💡 Hint

Think about how YARN manages resources for running tasks.

In Hadoop YARN, the ResourceManager allocates containers which are units of resources (CPU, memory) to run application tasks. Containers do not store data or manage network traffic directly.

❓ Predict Output

intermediate

Output of Container Allocation Log Snippet

Given the following YARN container allocation log snippet, what is the total memory allocated to containers?

Hadoop

2024-06-01 10:00:00,000 INFO ResourceManager: Allocated container container_01 with 2048 MB
2024-06-01 10:00:01,000 INFO ResourceManager: Allocated container container_02 with 1024 MB
2024-06-01 10:00:02,000 INFO ResourceManager: Allocated container container_03 with 4096 MB

A 7168 MB

B 7164 MB

C 7167 MB

D 7169 MB

💡 Hint

Add the memory sizes of all allocated containers.

The total memory is 2048 + 1024 + 4096 = 7168 MB.

❓ data_output

advanced

Resulting Container Allocation Table

Given the following resource requests and allocations, what is the final container allocation table?

Requests: Task1 needs 2 CPUs and 2048 MB memory, Task2 needs 1 CPU and 1024 MB memory.

Allocations: Task1 got 2 CPUs and 2048 MB, Task2 got 1 CPU and 512 MB.

Hadoop

import pandas as pd

requests = {'Task': ['Task1', 'Task2'], 'CPU_requested': [2, 1], 'Memory_requested_MB': [2048, 1024]}
allocations = {'Task': ['Task1', 'Task2'], 'CPU_allocated': [2, 1], 'Memory_allocated_MB': [2048, 512]}

req_df = pd.DataFrame(requests)
alloc_df = pd.DataFrame(allocations)

result = pd.merge(req_df, alloc_df, on='Task')
result

A [{'Task': 'Task1', 'CPU_requested': 2, 'Memory_requested_MB': 2048, 'CPU_allocated': 1, 'Memory_allocated_MB': 2048}, {'Task': 'Task2', 'CPU_requested': 1, 'Memory_requested_MB': 1024, 'CPU_allocated': 1, 'Memory_allocated_MB': 512}]

B [{'Task': 'Task1', 'CPU_requested': 2, 'Memory_requested_MB': 2048, 'CPU_allocated': 2, 'Memory_allocated_MB': 2048}, {'Task': 'Task2', 'CPU_requested': 1, 'Memory_requested_MB': 1024, 'CPU_allocated': 1, 'Memory_allocated_MB': 512}]

C [{'Task': 'Task1', 'CPU_requested': 2, 'Memory_requested_MB': 2048, 'CPU_allocated': 2, 'Memory_allocated_MB': 1024}, {'Task': 'Task2', 'CPU_requested': 1, 'Memory_requested_MB': 1024, 'CPU_allocated': 1, 'Memory_allocated_MB': 512}]

D [{'Task': 'Task1', 'CPU_requested': 2, 'Memory_requested_MB': 2048, 'CPU_allocated': 2, 'Memory_allocated_MB': 512}, {'Task': 'Task2', 'CPU_requested': 1, 'Memory_requested_MB': 1024, 'CPU_allocated': 1, 'Memory_allocated_MB': 1024}]

💡 Hint

Look carefully at the allocated CPU and memory for each task.

The merged table shows requested and allocated resources side by side. Task1 got full requested resources, Task2 got less memory than requested.

❓ visualization

advanced

Interpreting Container Allocation Visualization

You see a bar chart showing container memory allocation for 3 tasks: Task1 (2048 MB), Task2 (1024 MB), Task3 (4096 MB). Which statement is true about the visualization?

A Task3 has the highest memory allocation, twice that of Task1.

B Task2 has the highest memory allocation, more than Task3.

C All tasks have equal memory allocation.

D Task1 has the lowest memory allocation, less than Task2.

💡 Hint

Compare the bar heights representing memory sizes.

Task3's 4096 MB is twice Task1's 2048 MB. Task2 has the smallest allocation.

🔧 Debug

expert

Identifying Error in Container Allocation Code

What error does the following Hadoop container allocation pseudo-code produce?

containers = []
for i in range(3):
    container = {'id': f'container_{i}', 'memory': 2048 * i}
containers.append(container)
print(containers)

A The list 'containers' will contain three containers with memory 0, 2048, and 4096 MB.

B TypeError because 'containers' is not defined.

C Only one container will be in the list because append is outside the loop.

D SyntaxError due to missing colon after for loop.

💡 Hint

Check the indentation of the append statement.

The append is outside the loop, so only the last container is added once. The list ends with one container with memory 4096 MB.