You never size brokers in Confluent Cloud 17,245 . You pick a cluster type, and capacity is counted in Elastic Confluent 17,245 Units for Kafka 129 (eCKUs): each eCKU carries a share of ingress, egress, partitions, connections and requests, and an elastic cluster adds or drops eCKUs by itself as load changes, between a minimum and a ceiling you may lower to cap spending. Only Dedicated clusters use fixed CKUs that you add and remove by hand.
| Type | Capacity | Max ingress / egress | Partitions | Uptime SLA |
|---|---|---|---|---|
| Basic | 1-50 eCKU | 250 / 750 MBps | 1,500 | 99.5% |
| Standard | 1-10 eCKU | 250 / 750 MBps | 2,500 | 99.9%; 99.99% from 2 eCKU |
| Enterprise | 1-32 eCKU | 1,920 / 5,760 MBps | 96,000 | 99.9%; 99.99% from 2 eCKU |
| Freight | 2-152 eCKU | 9,120 / 27,360 MBps | 50,000 | 99.99% |
| Dedicated | CKUs, set by you | Per CKU | Per CKU | 99.95% one zone, 99.99% three |
The types differ in more than size. Basic suits development: public endpoints only and no RBAC roles on resources inside the cluster. Standard is the production default on public networking. Enterprise is reachable only over private networking (PrivateLink, Private Service Connect or AWS 24 's Private Network Interface) and scales quickly up to 10 eCKU, then about one eCKU every 20 minutes. Freight, so far in selected AWS regions, writes straight to object storage for cheap, high-volume logging at relaxed latency, and it does not support the idempotent producer or transactions, so the exactly-once patterns of Idempotent Producers and Transactions and Exactly-Once will not run on it. Dedicated is single-tenant capacity for the largest workloads and the widest choice of private networking; an organization paying by card can buy at most 4 CKUs per cluster, and one paying by invoice or through a cloud marketplace up to 24 before it must ask.
All types include Kafka ACLs, encryption in transit and at rest, and managed connectors. None lets you set broker configuration: topic settings are allowed within limits, but server.properties, the JVM and the KRaft quorum of The Kafka Log Under the Hood-Kafka 4.x in Docker are Confluent's business, the trade at the heart of every managed service.