Confluent Kafka
The built-in Confluent Kafka system type — scraping the Confluent Cloud Metrics API export endpoint, detection prefixes, starter checks for consumer lag, cluster load and hot partitions, and tuning notes.
Confluent Cloud is managed Kafka — the brokers are Confluent’s problem, but the usage is still yours: consumers lagging, a Dedicated cluster running out of headroom, one partition taking disproportionate ingress. Confluent publishes exactly these signals through its Metrics API, and this system type turns them into starter checks.
Key: confluent-kafka · applied automatically to services emitting metrics prefixed confluent_kafka_ or confluent.kafka..
Getting the telemetry
Section titled “Getting the telemetry”The Confluent Cloud Metrics API has a Prometheus-format export endpoint — scrape it with the Collector’s prometheus receiver using a Cloud API key:
receivers: prometheus/confluent: config: scrape_configs: - job_name: confluent-cloud scrape_interval: 60s scheme: https metrics_path: /v2/metrics/cloud/export params: resource.kafka.id: ["lkc-xxxxxx"] # your cluster id(s) static_configs: - targets: ["api.telemetry.confluent.cloud"] basic_auth: username: ${env:CONFLUENT_API_KEY} password: ${env:CONFLUENT_API_SECRET}Wire the receiver into a metrics pipeline with a resource processor setting a service.name, exactly as in Monitoring with the OpenTelemetry Collector.
What Sluicio detects
Section titled “What Sluicio detects”Metrics prefixed confluent_kafka_ or confluent.kafka.. Scraped from the export endpoint, names arrive in the underscored Prometheus form — confluent_kafka_server_consumer_lag_offsets, confluent_kafka_server_cluster_load_percent, confluent_kafka_server_hot_partition_ingress, and so on; the dotted prefix covers setups that translate the names to OTel conventions.
Starter checks
Section titled “Starter checks”| Check | Condition | Severity | Why it matters |
|---|---|---|---|
| Consumer lag | confluent_kafka_server_consumer_lag_offsets > 1,000, split by consumer_group_id | Warning | A group is falling behind its topics — same signal as self-hosted Kafka lag, served by Confluent. |
| Cluster load | Cluster load ratio > 0.8 | Warning | On Dedicated clusters, load approaching 1.0 means you’re out of CKU headroom — expect throttling; time to expand. |
| Hot partition ingress | Confluent reports a partition as hot on ingress | Warning | One partition absorbing outsized traffic — usually a skewed partition key — throttles that partition while the rest idle. |
Tuning notes
Section titled “Tuning notes”- Cluster load only exists on Dedicated clusters. On Basic and Standard clusters the metric isn’t reported and the check simply never fires — disable it there to keep the check list honest. 0.8 is a reasonable “start planning” line; how close to 1.0 you can cruise depends on how bursty your traffic is.
- Consumer lag carries the same advice as the Apache Kafka type: tune per group against real throughput, and add a duration. Note the export endpoint’s granularity — with one sample per minute, short spikes are invisible anyway.
- Hot partition alerts point at your partition keys, not at Confluent. The fix is usually rekeying or increasing partition count on the affected topic.
- The export endpoint returns the latest complete minute per metric; keep
scrape_intervalat 60s — scraping faster only re-reads the same sample.