DevLearn
Production Support

Troubleshooting Guide

Common Kafka issues, symptoms, root causes, and resolution steps

3

Critical

3

Warning

6

Total Issues

24/7

Support Ready

Symptoms

  • Messages piling up in topics
  • Consumers unable to keep up with producers
  • Increasing lag in kafka-consumer-groups output

Root Causes

  • Consumer processing too slow
  • Not enough consumers in the group
  • Network bottlenecks
  • Garbage collection pauses in Java consumers

Resolution Steps

  1. Scale out consumers (add more instances)
  2. Optimize consumer processing logic
  3. Increase partition count for parallelism
  4. Tune JVM settings for better performance

Diagnostic Commands

Check consumer lag

kafka-consumer-groups.sh --describe --group <group-name> --bootstrap-server localhost:9092

Monitor lag over time

kafka-consumer-groups.sh --describe --all-groups --bootstrap-server localhost:9092

Sample Log Messages

[Consumer clientId=consumer-1] Skipping fetch for partition orders-0 because it has no usable fetch position
[Consumer clientId=consumer-1] Setting offset for partition orders-0 to the committed offset 12345