Kafka

JR has been built with Apache Kafka in mind since the inception, so the Kafka support is pretty advanced.

Writing data to Apache Kafka

Just use the --output kafka (which defaults to console) flag and --topic flag to indicate the topic name:

jr run net_device -n 5 -f 500ms -o kafka -t test

If you don’t specify a key, ta null key will be used for each record. Using --key you can use a template for the key, to be embedded directly in the command:

For example:

jr run -k '{{key "KEY" 20}}' -f 1s -d 10s net_device -o kafka -t test

Another example:

jr run -k '{{randoms "ONE|TWO|THREE"}}' -f 1s -d 10s net_device -o kafka -t test

Autocreate topics

Topics autocreation is disabled in Confluent Cloud. If you are really lazy you can use the -a option, so JR will create the topic for you.

jr run -a -k '{{randoms "ONE|TWO|THREE"}}' -f 1s -d 10s net_device -o kafka -t mynewtopic

Alternatively, you can also create it explicitly from JR:

jr createTopic mynewtopic

If you want to specify number of partitions and replication Factor you can use the -p and -r flags:

jr createTopic mynewtopic -p 10 -r 2