Topic Configs

Configurations pertinent to topics have both a server default as well an optional per-topic override. If no per-topic configuration is given the server default is used. The override can be set at topic creation time by giving one or more --config options. This example creates a topic named my-topic with a custom max message size and flush rate:

$ bin/kafka-topics.sh --bootstrap-server localhost:9092 --create --topic my-topic --partitions 1 \
  --replication-factor 1 --config max.message.bytes=64000 --config flush.messages=1

Overrides can also be changed or set later using the alter configs command. This example updates the max message size for my-topic :

$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type topics --entity-name my-topic \
  --alter --add-config max.message.bytes=128000

To check overrides set on the topic you can do

$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type topics --entity-name my-topic --describe

To remove an override you can do

$ bin/kafka-configs.sh --bootstrap-server localhost:9092 --entity-type topics --entity-name my-topic \
  --alter --delete-config max.message.bytes

Below is the topic configuration. The server's default configuration for this property is given under the Server Default Property heading. A given server default config value only applies to a topic if it does not have an explicit topic config override.