17 January 2021
Cassandra is a popular, tried-and-true NoSQL database that supports key-value wide-column tables. Like any powerful tool, Cassandra has its ideal use cases - in particular, Cassandra excels at supporting write-heavy workloads, while having limitations when supporting read-heavy workloads. Cassandra's eventual consistency model and lack of transactions, multi-table support like joins, subqueries can also limit its usefulness.
However, using Cassandra as a metadata database for an object storage system introduces significant complexity resulting in data integrity and performance issues at scale - particularly if one wants to use their object store as a primary storage system. Object storage needs are far simpler and different from what Cassandra is built for.