Monedula
Writing & open source
Writing

Notes from the team.

09 Oct 2026 Release 9 min

Kafka Simulator v1.9 - the platform layer and a public URL format

Multi-Region Cluster observers, Cluster Linking and tiered storage complete the DR and storage story in twelve scenarios - and the playground's URL format goes public, with monedula-sim-link to turn a live cluster, or an AI agent's description, into a link.

25 Sept 2026 Release 6 min

Kafka Simulator v1.8 - multi-DC, DR and the Kafka CLI terminal

Stretched clusters, MirrorMaker 2 offset translation, failover and failback - and a terminal running the real Kafka CLI tools against the simulated cluster. The DR module explains the cluster shapes free play has offered since v1.3.

18 Sept 2026 Release 3 min

Kafka Simulator v1.7 - chaos and the Failure Lab

Kill brokers, split the network, and watch your cluster recover. v1.7 adds the Failure Lab to free play, six chaos scenarios, and a more usable mobile playground.

02 Sept 2026 Release 7 min

Kafka Simulator v1.5 + v1.6 - stretched clusters, storage and ops

Two packs at once. Free play completes its topology ladder with the 3-DC stretched and 2.5-DC witness clusters, and 19 new scenarios cover the log's lifecycle - retention, compaction, tiered storage - plus the KRaft control plane and the operations you run against a live cluster.

24 Aug 2026 Release 5 min

Kafka Simulator v1.4 - delivery semantics, transactions and active/active

Exactly-once, read_committed and the last stable offset, begin/commit/abort, and the consume–process–produce loop. The transactions module makes EOS - Kafka's hardest topic - something you can step through. Free play also gains a new cluster type: active/active.

04 Aug 2026 Release 5 min

Kafka Simulator v1.3 - durability and replication

The replication module arrives: ISR mechanics, the high watermark, acks=all and min.insync.replicas, leader election and what an unclean election actually loses. Twelve scenarios on the guarantees Kafka is famous for.

30 Jul 2026 Release 4 min

Kafka Simulator v1.2 - consumers and the rebalance

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.

24 Jun 2026 Education 9 min

Kafka is easier to understand when you can break 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.