What is records-lag-max?

• A. The lag per consumer
• B. The total lag across all partitions
• C. The maximum lag in terms of number of records for any partition in this window
• D. The average lag across partitions

Answer: (C)

Records-lag-max captures the worst lag you have across partitions. Lag is how far behind a consumer is from the latest records in a partition, measured in number of records. For each partition the consumer group is consuming, you can compute its lag; records-lag-max is simply the largest of those per-partition lags within the monitoring window. This shows the partition that’s furthest behind, which helps you spot bottlenecks or uneven throughput.

For example, if partition A has a lag of 50, partition B has 250, and partition C has 120, the records-lag-max is 250. It’s not the total lag across partitions, nor the average lag; it’s specifically the maximum lag value among all partitions.