retention

What is the difference between the following two retention configurations? offsets.retention.minutes log.retention.minutes I don't get how it differs or relate to each other. From my understanding, once the offset is removed, the record in the log is not accessible and vice versa. Is there something I have misunderstood? The offset is a pointer to the most recent message that has been consumed by a consumer. So if you read 10 messages, the offset moves 10 places. offsets.retention.minutes allows you to move the offset back to the beginning if it isn't changed within a set period of time. To

With Kafka 0.8.1.1, how do I change the log retention time while it's running? The documentation says the property is log.retention.hours , but trying to change it using kafka-topics.sh returns this error $ bin/kafka-topics.sh --zookeeper zk.yoursite.com --alter --topic as-access --config topic.log.retention.hours=24 Error while executing topic command requirement failed: Unknown configuration "topic.log.retention.hours". java.lang.IllegalArgumentException: requirement failed: Unknown configuration "topic.log.retention.hours". at scala.Predef$.require(Predef.scala:145) at kafka.log.LogConfig$