A dashboard that depends on Kafka events must still reach its data when a broker fails. A topic’s replication factor sets the number of copies maintained for each partition, with copies placed on different brokers. Because a partition is the unit of replication, the factor cannot exceed the cluster’s broker count. section 2.3
Choose the value alongside the write-availability requirements:
- The default replication factor is 1. Override it when a single broker failure must not put the partition’s data at risk. section 2.3.2
- Set min.insync.replicas to the minimum number of caught-up replicas, including the leader, required for a successful write. If fewer remain in sync, producers encounter an exception. section 2.3.2
- Treat the two settings as a durability decision informed by how critical the business data is, alongside producer acknowledgments and consumer offset commits. section 10.1.3
Three-broker dashboard cluster
A Customer 360 deployment starts with three brokers and specifies three replicas and min.insync.replicas of 2 for its topics. Copies remain distributed across the brokers; a successful write requires at least two replicas to be in sync. If fewer than two remain in sync, new writes fail rather than meeting a weaker acknowledgment requirement. section 2.3.3 section 2.3.2
asyncapi: 3.0.0
info:
title: Customer 360 Project
version: 1.0.0
description: >
This project aims to aggregate data from various sources, providing a
comprehensive view of customer information.
channels:
customerProfile:
description: Storing profile information of customers.
address: CUSTOMER_PROFILES
bindings:
kafka:
partitions: 9 #1
replicas: 3
topicConfiguration:
min.insync.replicas: 2 #2
transactions:
description: Information about customer transactions.
address: TRANSACTIONS
bindings:
kafka:
partitions: 9
replicas: 3
topicConfiguration:
min.insync.replicas: 2
The AsyncAPI 3.0.0 Kafka bindings record `replicas: 3` and `min.insync.replicas: 2` alongside each topic’s partition count. section 2.3.3
Record replication choices per topic rather than relying unexamined on defaults. Early topic design can focus on partition count, replication factor, and minimum in-sync replicas, then refine other settings as requirements become clearer. section 2.3 section 2.4.7
