How to clean up Kafka logs

The following steps illustrates the way to cleanup Kafka logs.

For any logs that appear to be overflowing and consuming disk space, you can use the following steps to clean up the logs from Kafka brokers

Note: Make sure the team is informed before doing this activity. This activity will delete the Kafka topic data

Steps

1. Backup list of log file names and their disk consumption data (optional)

   kubectl exec -it kafka-v2-0 -- du -h /opt/kafka-data/logs |tee backup_0.logs

   kubectl exec -it kafka-v2-1 -- du -h /opt/kafka-data/logs |tee backup_1.logs

   kubectl exec -it kafka-v2-2 -- du -h /opt/kafka-data/logs |tee backup_2.logs

2. Cleanup the logs

   kubectl exec -it kafka-v2-0 -- rm -rf /opt/kafka-data/logs/* -n kafka-cluster

   kubectl exec -it kafka-v2-1 -- rm -rf /opt/kafka-data/logs/* -n kafka-cluster

   kubectl exec -it kafka-v2-2 -- rm -rf /opt/kafka-data/logs/* -n kafka-cluster

3. If the pod is in crashlookbackoff state, and the storage is full, use the following workaround:

• Make a copy of the pod manifest

  kubectl get statefulsets kafka-v2 -n kafka-cluster -oyaml > manifest.yaml

• Scale down the Kafka statefulset replica count to zero

  kubectl scale statefulsets kafka-v2 -n kafka-cluster --replicas=0

• Make the following changes to the copy of the statefulsets manifest file

  • Modify the command line from:

containers:
- command:
  - sh
  - -exc
  - |
    export KAFKA_BROKER_ID=${HOSTNAME##*-} && \
    export KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://${POD_NAME}.kafka-v2-headless.${POD_NAMESPACE}:9092,EXTERNAL://${HOST_IP}:$((31090 + ${KAFKA_BROKER_ID})) && \
    exec /etc/confluent/docker/run

To

containers:
- command:
  - sh
  - -exc
  - |
    tail -f /dev/null

• Apply this statefulsets manifest and scale up statefulsets replica count to 3, the pod should be in a running state now and follow [step 2].

• Again scale down the Kafka statefulset replica count to zero

  kubectl scale statefulsets kafka-v2 --replicas=0 -n kafka-cluster

• Make the following changes to the copy of the statefulsets manifest file

  • Modify the command line from:

containers:
- command:
  - sh
  - -exc
  - |
    tail -f /dev/null

To

containers:
- command:
  - sh
  - -exc
  - |
    export KAFKA_BROKER_ID=${HOSTNAME##*-} && \
    export KAFKA_ADVERTISED_LISTENERS=PLAINTEXT://${POD_NAME}.kafka-v2-headless.${POD_NAMESPACE}:9092,EXTERNAL://${HOST_IP}:$((31090 + ${KAFKA_BROKER_ID})) && \
    exec /etc/confluent/docker/run

• Apply this statefulsets manifest and scale up statefulsets replica count to 3