Kafka follows a pub-sub mechanism wherein producer writes to a topic and one or more consumers read from that topic. However, Reads in Kafka always lag behind Writes as there is always some delay between the moment a message is written and the moment it is consumed. This delta between Latest Offset and Consumer Offset is called Consumer Lag There are various open source tools available to measure consumer lag e.g. LinkedIn Burrow. Confluent Kafka comes with out of the box tools to measure lag.