AWS MSK and Confluent. Are they really Serverless?
Blog post from Upstash
The analysis compares three managed Kafka services—AWS MSK (Serverless), Confluent Cloud, and Upstash Kafka—focusing on their serverless nature and pricing models. AWS MSK and Confluent Cloud, which charge for inactive clusters, are examined for their inability to scale pricing to zero, thus questioning their serverless classification. AWS MSK's pricing mirrors Confluent Cloud's but with a lower cluster-per-hour cost. Upstash Kafka, however, truly scales to zero by not charging for inactive clusters and offers a competitive pricing model based on message count, with a monthly cap of $360 to prevent excessive costs, making it suitable for high-throughput scenarios. The study concludes that Upstash aligns more closely with serverless principles by only charging for actual usage, while AWS MSK and Confluent Cloud do not fully meet this criterion.