Monedula — WritingNotes from the Monedula team on writing and open source.https://monedula.dev/Kafka Simulator v1.2 — consumers and the rebalancehttps://monedula.dev/blog/kafka-simulator-v1-2-consumers-and-rebalances/https://monedula.dev/blog/kafka-simulator-v1-2-consumers-and-rebalances/Consumer groups, assignment strategies, static membership and the two timeouts that decide when a member is gone. Ten new scenarios that make the rebalance — Kafka's most misunderstood moment — something you can watch instead of guess at.Thu, 30 Jul 2026 00:00:00 GMTKafka Simulator v1.1: Understanding Kafka Producer Semanticshttps://monedula.dev/blog/kafka-simulator-v1-1-producer-semantics/https://monedula.dev/blog/kafka-simulator-v1-1-producer-semantics/Kafka Simulator v1.1 adds ten scenarios covering producer batching, partitioning, compression, backpressure, retries, and idempotence.Tue, 14 Jul 2026 00:00:00 GMTKafka client metrics over OTLP — one more piece of the puzzlehttps://monedula.dev/blog/kafka-monedula-metrics-kip-714/https://monedula.dev/blog/kafka-monedula-metrics-kip-714/KIP-714 lets Kafka clients push their own metrics to brokers over OTLP. monedula-metrics-reporter now forwards those metrics too, next to broker SPI and Yammer metrics.Tue, 07 Jul 2026 00:00:00 GMTKafka is easier to understand when you can break ithttps://monedula.dev/blog/kafka-simulator-learn-kafka-by-breaking-it/https://monedula.dev/blog/kafka-simulator-learn-kafka-by-breaking-it/Kafka's most important lessons live in the transitions: before and after a broker dies, before and after the ISR shrinks. We built a browser-based simulator so you can break a cluster safely and watch exactly why it reacts the way it does.Wed, 24 Jun 2026 00:00:00 GMTFrom Kafka ACLs to Confluent RBAC: A Safe Migration Path with a New Open-Source Toolhttps://monedula.dev/blog/kafka-acls-confluent-rbac-migration-monedula-acl-rbac-converter/https://monedula.dev/blog/kafka-acls-confluent-rbac-migration-monedula-acl-rbac-converter/Moving an existing Kafka estate from ACLs to Confluent RBAC is a risk-management exercise, not a syntax conversion. Here's a safe, auditable, repeatable migration workflow — and the tool we built for it.Wed, 17 Jun 2026 00:00:00 GMTDo Kafka metrics have to be so difficult?https://monedula.dev/blog/kafka-metrics-opentelemetry-otlp-monedula-metrics-reporter/https://monedula.dev/blog/kafka-metrics-opentelemetry-otlp-monedula-metrics-reporter/Why Kafka metrics are painful, why JMX dashboards often show no data, and how to export Kafka metrics natively over OTLP.Tue, 26 May 2026 00:00:00 GMT