Kafka: Consumer lag is the number that matters in production

Lag is the distance between the log end offset and the group's committed offset - growing lag means you are falling behind.

Code

kafka-consumer-groups.sh --bootstrap-server localhost:9092 \
  --describe --group orders-service

Output

TOPIC   PARTITION  CURRENT-OFFSET  LOG-END-OFFSET  LAG
orders  0          182034          182040          6
orders  1          97112           241880          144768   <- this one is stuck

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Published 2026-08-11