Acknowledgment modes (acks=0, 1, all) in Kafka - Step-by-Step Execution

Process Flow - Acknowledgment modes (acks=0, 1, all)

Producer sends message

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Check acks setting

Shows how Kafka producer waits for acknowledgments based on the acks setting before continuing.

Execution Sample

Kafka

producer.send(record, acks=0)
producer.send(record, acks=1)
producer.send(record, acks='all')

Sends messages with different acknowledgment modes to Kafka.

Process Table

Step	acks value	Action	Wait for	Result	Continue
1	0	Send message	No one	No confirmation	Immediately
2	1	Send message	Leader broker	Leader confirms	After leader ack
3	all	Send message	All in-sync replicas	All confirm	After all acks
4	-	Stop	-	No more messages	-

💡 Producer stops sending after all messages are sent with specified acks.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	Final
acks	-	0	1	all	all
confirmation_received	false	false	true	true	true
producer_continues	true	true	true	true	true

Key Moments - 3 Insights

Why does acks=0 not wait for any confirmation?

Because as shown in execution_table row 1, acks=0 means the producer sends the message and immediately continues without waiting for any broker acknowledgment.

What does acks=1 guarantee about the message?

As per execution_table row 2, acks=1 waits for the leader broker to confirm the message, ensuring it is received by the leader but not necessarily replicated yet.

How does acks='all' improve message durability?

According to execution_table row 3, acks='all' waits for all in-sync replicas to confirm, ensuring the message is fully replicated and durable before continuing.

Visual Quiz - 3 Questions

Look at the execution_table, at which step does the producer wait for all replicas to confirm?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Check the 'Wait for' column in execution_table row 3.

According to variable_tracker, what is the value of 'confirmation_received' after step 1?

A false

B true

C 'all'

D undefined

💡 Hint

Look at the 'confirmation_received' row under 'After Step 1' in variable_tracker.

If acks is set to 1, when does the producer continue sending messages?

A After all replicas confirm

B Immediately after sending

C After leader broker confirms

D Never continues

💡 Hint

Refer to execution_table row 2 under 'Continue' column.

Concept Snapshot

Kafka producer acks modes:
acks=0: No wait, no confirmation, fastest but risky.
acks=1: Wait for leader ack, safer.
acks=all: Wait for all replicas, safest.
Choose based on durability vs latency needs.

Full Transcript

This visual execution shows how Kafka producer's acknowledgment modes control message sending. When acks=0, the producer sends and continues immediately without waiting for confirmation. With acks=1, it waits for the leader broker to confirm receipt before continuing. With acks='all', it waits for all in-sync replicas to confirm, ensuring full replication. Variables like 'confirmation_received' track if acknowledgments arrived. This helps balance speed and safety in message delivery.