Read-write balanced pattern
In an IoT application with Cassandra as the data store, if the amount of write and the amount of read is balanced, then it is a tricky situation. It is difficult to have high availability for write as well as read. So, the best way to handle the situation is to go with the formula (W + R) > N. In other words, the sum of the number of nodes written and the number of nodes read is greater than the replication factor. It is also common to have two different but replicated clusters of Cassandra nodes, and in that, one is optimized for fast reads and the other for fast writes. But this has to be done with caution and the main reason is because once the data is written into one cluster, how fast that should be available for read from the other cluster. It is purely a business-rule-based requirement and there is no hard-and-fast rule that can be applied.
Motivations/solutions
Many of the financial transactions are highly read-write balanced patterns. This is commonly...