kafka.producer.buffer_total_bytes

When CockroachDB changefeeds emit to Kafka and the high_water_timestamp lag increases significantly, it indicates the Kafka sink cannot keep up with database changes. This creates backpressure where database CDC events queue up, potentially causing CockroachDB performance degradation.

When producer buffer memory is exhausted, send calls block waiting for space, causing application threads to stall and reducing overall throughput.