Why does Kafka recommend setting num.io.threads to a value close to the number of available CPU cores for disk I/O optimization?

hard📝 Conceptual Q10 of 15

Kafka - Performance Tuning

Why does Kafka recommend setting num.io.threads to a value close to the number of available CPU cores for disk I/O optimization?

ATo minimize network traffic between brokers

BTo maximize parallel disk operations without causing CPU contention

CTo reduce the number of partitions per topic

DTo limit the maximum message size

Step-by-Step Solution

Solution:

Step 1: Understand CPU and io thread relationship
Setting io threads near CPU core count allows Kafka to use CPU efficiently for parallel disk I/O.
Step 2: Avoid CPU contention
Too many threads cause CPU contention; too few underutilize CPU. Matching cores balances performance.
Final Answer:
To maximize parallel disk operations without causing CPU contention -> Option B
Quick Check:
num.io.threads ~ CPU cores for balanced disk I/O [OK]

Quick Trick: Match io threads to CPU cores for best disk I/O [OK]

Common Mistakes:

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