YAKLE (Yet Another Kafka Lag Exporter)

Kafka lag exporter are either broken, slow or only send metrics to influx. This is my attempt to write my own. This is inspired by burrowx, but simplified with the more robust logic I could think of. Yakle basically export the same sets of metrics as danielqsj/kafka_exporter and kminion. Dashboards are based on kminion one but a bit extended.

One cool feature compared to other exporters is that yakle can reports not only offset lag but also time lag (real time lag, not interpolated). Be aware that this only work for non compacted topics and that this feature is relatively slow (need to fetch lot of individual offsets). Yakle is "production" tested and worked since months in our environment (dozen of kafka clusters, hundred of brokers/topics/groups with many partitions) Yakle is tested fast enough. Parallelism is set to 10 workers by default. You can try to increase it but this is not measured faster and put a lot of pressure on kafka cluster.

Usage

Usage of ./yakle:
  -kafka-brokers="localhost:9092": address list of kafka brokers to connect to
  -kafka-fetch-timestamp=false: enable timestamps calculation
  -kafka-label="kafka-cluster": kafka cluster name for labeling metrics
  -kafka-workers=10: number of parallel workers for fetching metrics
  -log-debug=false: enable debug and sarama logging
  -refresh-interval=30: interval for refreshing metrics
  -topic-filter="^__.*": regex for excluding topics, default to internal topics
  -group-filter="^__.*": regex for excluding groups, default to internal groups
  -web-listen-address=":8080": address (host:port) to listen on for telemetry
  -web-telemetry-path="/metrics": path under which to expose metrics

Flags can be also be passed as environment variables.

Docker image exist at dockerhub ut0mt8/yakle:latest

Exposed metrics

Common Labels

cluster: Cluster name topic: Topic name partition: Partition ID group: Consumer group name

Metrics

Global metrics

Metric	Description
kafka_cluster_info{cluster, broker_count, controller_id, group_count, topic_count}	General informations for the cluster
kafka_broker_info{cluster, broker_id, address, is_controller, rack_id}	Informations for a given broker

Topic metrics

Metric	Description
kafka_topic_info{cluster, topic, partition_count, replication_factor}	Informations for a given topic
kafka_topic_broker_logdir_size{cluster, topic, broker, path}	Logdir size for a given topic/broker

Topic / Partition metrics

Metric	Description
kafka_topic_partition_info{cluster, topic, partition, leader, replicas, insync_replicas}	Informations for a given topic/partition
kafka_topic_partition_not_preferred{cluster, topic, partition}	Boolean indicating if the leader don't use its preferred broker for a given topic/partition
kafka_topic_partition_under_replicated{cluster, topic, partition}	Boolean indicating if all replicas are in sync for a given topic/partition
kafka_topic_partition_newest_offset{cluster, topic, partition}	Latest commited offset for a given topic/partition
kafka_topic_partition_oldest_offset{cluster, topic, partition}	Oldest offset available for a given topic/partition
kafka_topic_partition_oldest_time{cluster, topic, partition}	Timestamp in ms of the oldest offset available for a given topic/partition

Consumer group metrics

Metric	Description
kafka_group_info{cluster, group, coordinator_id, state, members_count}	Informations for a given group
kafka_group_topic_partition_current_offset{cluster, group, topic, partition}	Current offset for a given group/topic/partition
kafka_group_topic_partition_offset_lag{cluster, group, topic, partition}	Offset lag for a given group/topic/partition
kafka_group_topic_partition_time_lag{cluster, group, topic, partition}	Time lag (in ms) for a given group/topic/partition

Todo

• Add unit tests...