For the latest stable version, please use Korvet 0.12.5!

Logging

Korvet uses Logback for logging with JSON output for easy parsing.

Log Format

Logs are output in JSON format by default:

{
  "timestamp": "2024-01-15T10:30:45.123Z",
  "level": "INFO",
  "logger": "com.redis.korvet.server.KorvetServer",
  "message": "Started KorvetServer in 2.5 seconds",
  "thread": "main"
}

Log Levels

Configure log levels via environment variables:

# Root level
export LOGGING_LEVEL_ROOT=INFO

# Korvet components (default)
export LOGGING_LEVEL_COM_REDIS_KORVET=INFO

# Spring framework
export LOGGING_LEVEL_ORG_SPRINGFRAMEWORK=WARN

# Redis client
export LOGGING_LEVEL_IO_LETTUCE=INFO

Or in application.yml:

logging:
  level:
    root: INFO
    com.redis.korvet: INFO
    org.springframework: WARN
    io.lettuce: INFO

Structured Logging

Korvet includes structured fields in logs:

  • topic: Topic name

  • partition: Partition number

  • offset: Message offset

  • clientId: Kafka client ID

  • correlationId: Request correlation ID

Log Aggregation

Filebeat

Ship logs to Elasticsearch:

filebeat.inputs:
- type: container
  paths:
    - '/var/lib/docker/containers/*/*.log'
  processors:
    - decode_json_fields:
        fields: ["message"]
        target: ""

output.elasticsearch:
  hosts: ["elasticsearch:9200"]

Fluentd

<source>
  @type tail
  path /var/log/korvet/*.log
  pos_file /var/log/korvet/korvet.log.pos
  tag korvet
  <parse>
    @type json
  </parse>
</source>

<match korvet>
  @type elasticsearch
  host elasticsearch
  port 9200
  index_name korvet
</match>

Troubleshooting Logs

Korvet defaults to INFO logging. Raise specific components to DEBUG only while troubleshooting:

export LOGGING_LEVEL_COM_REDIS_KORVET_KAFKA=DEBUG
export LOGGING_LEVEL_COM_REDIS_KORVET_REDIS=DEBUG
export LOGGING_LEVEL_COM_REDIS_KORVET=DEBUG

Next Steps