Producers and Producer Settings

Producer Basics

A producer sends records to topics. The mandatory configuration is bootstrap.servers and key/value serializers. A record carries a topic, key, value, headers and an optional timestamp.

Keys and Partitioning

Records with the same key go to the same partition, preserving per-key order - e.g., all events for user 42 land in one partition. Without a key, producers round-robin across partitions.

Config: acks

acks=all          # strongest durability, wait for ISR
acks=1            # leader confirms alone
acks=0            # fire and forget

acks=all is the recommended default for production systems that cannot afford lost records.

Retries and Idempotence

retries=5
enable.idempotence=true   # prevents duplicates on retry
compression.type=lz4

Idempotent producers tag records so retries never duplicate precise offsets; compression lowers network bytes.

Producer Code Shape

// Java-style pseudocode
ProducerConfig acks = all; enable.idempotence = true;
producer.send(new ProducerRecord<>("orders", key, value), callback);

Key Points

• Keys guarantee per-partition order.
• acks controls the durability/throughput trade.
• Idempotence removes duplicate emissions.
• Serializers drive the record format.